Grow Great Fruit
Guide:
What’s bugging
my fruit?
Common Insect Pests of
Deciduous Fruit Trees
Mt Alexander
Fruit Gardens
Grow Great
Fruit Guide
How to use this book
This book is intended to be a general guide to the most common pests of deciduous fruit
trees, not an exhaustive list of insects—we’re orchardists, not entomologists. It’s largely
based on our experience, and purposely has a focus on practical solutions for the pests that
are likely to get in the way of you harvesting delicious, edible fruit from your trees.
We’ve included a lot of photos of the insects, and the damage they produce, to help
familiarise you with the types of insects you’re likely to meet in your garden. The reality is,
unless you take a particular interest or have training in identifying insects, you’re unlikely to
ever know what most of the insects you see are. And that’s just fine—as long as you protect
your trees and your fruit from serious damage, in the ways we describe in this book, then
there’s no need to identify them. Just stand back and watch in awe as the natural world of
predator and prey sorts itself out.
Acknowledgements
A great deal of the information in this book is the result of our own experience. We’ve learnt
mostly by trial and error, by being subjected to a wide range of extreme environmental
conditions, and by being open to learning from our mistakes, as well as our successes.
There’s a few people we’d like to thank for being generous in allowing us to use their
resources and photos—Kevin Dodds from the NSW Department of Primary Industries, Mallik
Malipatil from the Victorian Department of Primary Industries, Jerry Tangren from Washington
State University and Alan Biggs from West Virginia University. Individual photo credits are
listed at the back of the book.
Disclaimer
We make every effort to ensure the information given in this guide is accurate. While
we hope you find this information of use, we do not guarantee that the book is without flaws
of any kind, or is appropriate for your particular purpose, or will be implemented without
regard to a number of variables outside of our control, and therefore we disclaim all liability
for any error, loss or other consequence which may arise from you relying on any information
in this book.
© Mt Alexander Fruit Gardens 2014
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© Mt Alexander Fruit Gardens 2014
Contents
Our story..........................................................1
Introduction....................................................3
The eight key steps to organic pest control.....6
Life cycles of insect pests................................8
Fruit tree hygiene..........................................12
The insect pests.............................................14
Aphids.......................................................14
Carpophilus beetle.....................................17
Codling moth.............................................19
Earwigs.....................................................22
Fruit tree borer..........................................26
Garden weevil............................................27
Grasshoppers............................................29
Heliothis....................................................30
Mealybug...................................................31
Pear leaf blister mite.................................32
Pear and cherry slug..................................33
Rutherglen and harlequin bugs....................35
San Jose scale............................................36
Thrips........................................................37
Predator insects.............................................39
Make your own organic pesticides..................41
Insect pest control through the seasons.........46
Contact us......................................................47
References and photo credits.........................48
3
© Mt Alexander Fruit Gardens 2014
Our story
H
i, Hugh and Katie Finlay
here, thanks for reading
our story. We draw on
more than 16 years’ experience
as orchardists to bring you this
guide to common insect pests of
deciduous fruit—and believe us,
we’ve met them all!
Mt Alexander Fruit Gardens is
our organic farm, in the foothills
of Mt Alexander at Harcourt, in
central Victoria, Australia. This is
a traditional fruit growing area,
with great climate and granitic
soil that grows terrific tasting
fruit. In fact, Harcourt has been
famous for its apples for more
than 150 years. In the early
days of European settlement,
a lot of other types of fruit
were also grown in this district,
including many of the heritage
varieties of apricots, peaches,
nectarines, plums, and cherries
that we’ve reinstated on our
farm.
Since we came home to
the family farm in 1998, our
climate’s been anything but
‘normal’—in fact, because of
the effects of climate change,
we don’t really know what
normal is any more! In the
last 10 years we've seen some
pretty wild conditions—from
drought to flood and everything
in between—which has been
very challenging at times, but
means we’ve learnt lots about
growing fruit in a wide variety of
conditions.
Our farm is planted like an
1
old fashioned ‘garden’ (the
early name for an orchard) with
small plantings of more than 90
varieties, providing an extended
season of fresh fruit off the tree
for almost 6 months.
With a combination of careful
planning, looking after the trees
well, good storage, and a range
of preserving techniques, we’ve
turned the farm into a working
demonstration of how to keep
farming (in fact we don’t think
there’s anything conventional
about it, and prefer to call it
‘chemical farming’).
But there were all sorts of
barriers to switching to organic
growing—some real, and some
imagined! At the beginning
we just couldn’t imagine how
we could manage to grow fruit
without chemicals to solve all
our ‘problems’.
“Our farm is a working demonstration of how
to keep your family supplied with home grown
organic fruit all year round...”
your family supplied with homegrown organic fruit all year
round.
We came home to the farm
after we’d both tried many
different and diverse careers,
including politics, sales, business
services, travel writing for
Lonely Planet, and editing
(just to name a few), and both
had successful and exciting
careers in the city. But we found
ourselves drawn to the country
to give our kids the carefree
and natural upbringing we didn’t
think city life would provide.
Coming home to the family farm
seemed like the natural thing to
do.
Almost straight away we
struck a problem—we absolutely
hated using the chemicals that
are involved with ‘conventional’
But the more we found out
about the poisons we were
using, the more horrified we
became and, one after another,
we just stopped using them. And
then a most miraculous thing
happened! Most of our perceived
problems disappeared.
And so began an amazing
journey of exploration,
education, and experience, as
we discovered the truth behind
our problems (that in fact we’d
been causing most of them with
the poisons we had been using),
began to understand how to
work with—instead of against—)
nature, and truly learned
to understand, value, and
appreciate our most amazing
asset—the soil!
By 2008 we were ready to
apply for organic certification
© Mt Alexander Fruit Gardens 2014
with the National Association of
Sustainable Agriculture Australia
(NASAA), and by 2010 we
had achieved our first level of
certification!
Now we proudly use organic
growing methods—and teach
them—not only because it's
better for everyone's health, but
because we're acutely aware of
how fast the climate is changing,
and we want our farm to be part
of the solution, not part of the
problem!
Being certified organic means
that everything we do (and
everything we use on our farm)
must comply with the Australian
Organic Standards. We're
audited once a year by a NASAA
officer, who has the legal right
to look at EVERYTHING we do,
including all our bookwork and
procedures.
But we don’t mind—in fact,
we wholeheartedly support
organic certification, and love
that it's such a rigorous process,
because we think that gives
the people who buy our fruit
the confidence that we actually
are doing everything the right
way, and not just saying that
we are. It's too easy for people
to say they're organic when
what they mean is spray free,
or almost spray free. When
sort that fed the entire human
race before about 1920 when
superphosphate was invented,
and our soils were ruined!).
Natural fertility relies on using
compost, compost tea, and
other forms or organic matter
to create healthy soil, full of
microbes that provide the trees
with nutrients.
Why did we start
teaching?
B
ecause, as organic farmers,
we're connected to the land,
and to our community, both
local and global! We want to
share what we know, to give
people the skills to grow their
own food.
As well as that, we’ve talked
to thousands of home fruit
growers over the years when
we sell our fruit at markets,
and it was depressing that we
were hearing the same simple
mistakes being made time
and again. If we had a dollar
for every time we’ve heard a
gardener tell us they didn’t get
any fruit from their tree this
year, we’d be very rich!
We were frustrated because
we knew we had simple
solutions to all these problems—
but by the time we heard about
“With our experience, we’re in a great position to
help you get the skills you need...”
you're shopping, if someone is
claiming to be organic, ask them
who they're certified with, and if
they're not, ask them why not!
Being certified organic means
(amongst other things) that no
artificial fertilisers are used on
the farm. We rely instead on
natural fertility (you know, the
2
them, it was too late to save the
crop. We realised that we had
the answers, but that people
needed to be delivered the
information before the problems
happened!
We’ve also heard (more times
than we can count) that
• most people know it's much
healthier to eat organic food
(we agree, we wish the
whole world could afford to
eat organics!),
• many people worry about
food security for their kids
as the world's population
increases,
• most gardeners want to
improve the environment,
and
• almost no-one wants to use
chemicals on their homegrown food—but they don’t
know what else to do!
You may not know it, but if
you’re reading this, you're part
of a huge movement of people
interested in growing their own
food. With our experience, we're
in a great position to help you
get the skills you need, which
is why we came up with the
Grow Great Fruit membership
program, and this range of
guides. The information is
simple to read, simple to use,
and will help you to grow a great
crop of fruit, every year!
© Mt Alexander Fruit Gardens 2014
Introduction
Why we wrote this book
W
e only write about what we know about, so
this book is about the common pests that
affect the types of fruit trees we grow—cherries,
apricots, peaches, nectarines, apples and pears.
We have a long history of fruit-growing
experience behind us, in fact we’re the third
generation of orchardists in the family. Since we
took over Katie’s family farm in 1998, converted
the farm to organic production in 2008, and with
a combination of training, experience and trial
and error, we’ve come up with organic solutions to
most fruit-growing problems.
Of course there are many more potential
pests of fruit trees than those listed in this book.
We’ve included these because they are the most
common, and the most problematic.
One of our key discoveries when we converted
to organic production was that many of the
common pests either disappeared, or damage
was reduced to the point where it ceased to be a
problem. Orchards or gardens where chemicals
are habitually used have more pest problems,
because the chemicals kill the predator insects,
kill the soil microbes, and throw the natural
control system out of balance.
If you have pest problems that are not included
in this book, you should still find the chapter on
the Eight Key Steps to Organic Pest and Disease
Control valuable to help get your system back in
balance. Once you
improve your soil
and encourage a
wide diversity of
predator insects
into your garden,
you may find the
problem disappears
by itself. We had
this happen again
and again as our
system recovered
from using
chemicals.
If you want
information about
pests that affect
deciduous fruit
trees in your part
of the world that
are not included in
this book, please
contact us and we’ll
do the research and
maybe include it in
a later edition.
3
Pest control: why organic?
D
o you eat organic food? More and more people
every year are deciding to eat organics, with
the global organic industry growing from $20
billion worldwide in 2001 to $63 billion in 2012,
and continuing to grow rapidly.
People switch to organics for different reasons,
and health is one of the main motivators. A 2014
Australian study (Australian Organic Market
Report 2014) found that half of organic shoppers
first bought organics because they became more
aware of the positive impact organics had on their
personal health, with 16% doing so because of
illness. A further 32% said that they first bought
organics for environmental reasons and 25%
because of animal welfare concerns associated
with conventional food producing systems.
Another recent study in Australia, published
in Environmental Research, has proven this
instinct to be correct, showing that eating a diet
consisting of at least 80% organic food can reduce
organophosphate pesticide levels in urine by 89%
in adults, with results showing after only 8 days.
We choose (and teach) organic pest control
not only for the health benefits for us humans,
but also because it’s so much better for the
environment to restore soil health, and restore
the natural balance between pests and predators
in the ecosystem. And it works!
© Mt Alexander Fruit Gardens 2014
Why are healthy trees less likely to
be attacked by pests and diseases?
I
t’s often not a matter of luck whether or not
your trees get sick—the science shows that
healthy trees are much less likely to be attacked
by insects, especially sap-sucking bugs.
Unfortunately, there are some limitations! No
matter how healthy your trees are, they can’t
protect themselves against birds or fruit bats,
or the big pests like hares and rabbits, and
even healthy trees are likely to be attacked by
Queensland fruit fly and Codling moth.
Nor can we influence the extreme weather
conditions that create favourable conditions for
pests and diseases. But there are many factors
you can influence to give your fruit trees the best
possible chance of defending themselves.
Plants have a secret life of which we know
little, and have a well-organised natural defence
system to protect themselves! They have a highly
evolved natural defence system against attack
by disease (much like humans), that includes
plant hairs, developing thick cuticles, and making
a range of protective chemicals. And just like
humans, the first layer of defence is the plant’s
skin, ie, the tree’s bark, the thick skin of stems,
and the waxy layer on leaves.
The protective chemicals that plants make
have various effects on the bugs that eat them;
they might stop the insects growing properly,
sterilise them, repel them, or mask how delicious
the plant really is. Some plants even make their
own poisons—some acacias will produce hydrogen
cyanide in response to insects feeding on their
leaves!
Other defence mechanisms that trees use
include producing gum (as seen in gummosis,
which is usually the tree’s response to attack by
fungus or bacteria), allowing a section of the leaf
around the affected area to die, causing a leaf
spot, or by dropping infected leaves altogether.
Have you ever wondered why some people
succumb to every cold in winter, and others
never seem to get sick? Or have you had the
experience of having a fruit tree mysteriously get
sick and die, while the tree over the fence is in
blooming health? The pathogens (microbes that
cause infectious diseases, such as fungal spores)
are commonly present in the environment, just
4
as the microbes that cause the common cold
are everywhere. So for many common diseases,
whether or not an individual (tree or person)
gets sick is often more to do with the strength of
their immune system than the presence of the
pathogen.
Some trees are naturally resistant to some
diseases, and increasingly, as new varieties are
being developed, they are often bred specifically
for disease resistance. A great example of this
is the Honeycrisp apple, which is very resistant
to black spot (apple scab)—a common fungal
disease.
Traditionally, resistance has been bred into
fruit varieties using natural breeding selection
methods, but there is a worrying trend towards
using genetic modification, where genes are
artificially spliced into fruit to add particular
characteristics. Why are we worried? Because
there is now a mountain of scientific evidence
showing that artificially meddling with genetics in
this way can have extremely harmful effects on
human health. We definitely recommend staying
away from GM fruit!
Where is my tree’s immune system?
F
ruit trees have a vascular system, which is
made up of xylem (which takes water and
dissolved nutrients up from the soil up into the
leaves), and phloem (which takes the sugars that
are made in the leaves down into the roots, where
they are used to feed the microbes in the soil,
amongst other things)!
If all the necessary minerals and trace
elements are available in the soil (tree health
invariably comes back to the soil...), the xylem
transports them from the roots into the tree,
where they are rapidly made into complete
proteins. The resulting healthy plants will have
a strong vascular system and strong, healthy
stems and leaves that are much harder for
insects to bite into. The tree can also make new
tissues quickly, have harder cell walls and tougher
cuticles, are able to produce chemical protection,
and can rapidly recover from wounds or pest
attack.
Problems arise if the soil is deficient in
nutrients, if the right balance of nutrients is not
present in a plant-available form, or if the tree
© Mt Alexander Fruit Gardens 2014
is under stress for some other reason. This is
when plants become vulnerable, because without
some crucial minerals, they can’t build strong
cell walls or thick outer leaf layers. As well as the
devastating physical effects, mineral-deficient
plants will also give off chemical signals that tell
the insects that they’re weak, and ripe for attack.
Insect pests target weak, deformed,
nutritionally deficient or unbalanced plants.
Insects love trees like this, because they have
lots of incomplete proteins (called amino acids)
in their sap; the insects can digest amino acids
easily, whereas they can’t digest and break down
complete proteins.
So, not only are the trees easier for the insects
to attack because they have weaker cell walls,
they are also actually sending out signals to let
the insects know they’re weaker (traitors!), and
by having lots of free amino acids in their sap, the
trees provide the perfect, easily digestible food for
insects. It’s a lose-lose-lose situation!
Can organic farming feed the world?
A
lot of people worry that if they don’t use
chemicals in their gardens to control pests,
they won’t get a good yield. (This is the same
argument chemical and GM companies use to
scare people into believing the planet will starve
to death if we don’t all use chemicals on our
crops!)
Luckily, it’s not true! You might be surprised to
know that many studies (including comparative
studies over more than 20 years by the Rodale
Institute in America) have shown that organic
farming systems can produce a yield between
80% and 110% of chemical systems. They also
use (on average) 50% less fertiliser, 97% less
pesticide, and up to 53% less energy, so they can
be much more efficient. Organic farms are also
more resilient, and tend to survive conditions like
droughts and hurricanes better than chemical
farms (usually due to higher carbon in the soil).
But be warned, if you’re shifting from chemical
gardening to organic, you need to be patient! It
can take a while for nature to repair the damage,
and for the crucial predator insect populations to
build up again in your garden.
Why do so many farms use
chemicals, and what do they use
them for?
C
ontrolling pests and diseases with chemicals
needs less labour input, gives the farmer a
greater sense of control, and is all a lot of farmers
know! As farmers ourselves, we understand how
distressing it is to see your precious crop attacked
by pests or diseases, and many’s the time we’ve
wished we had a magic wand to fix the problem!
At the time of writing, in Australia 77 pesticides
are registered for use against Codling moth, there
are 546 registered chemicals for killing aphids,
and 261 registered fungicides. Some of the
commonly used pesticides are organophosphates
5
including Malathion, Diazinon, and Chlorpyrifos,
as well as carbamates and synthetic pyrethroids.
There are also 3,076 registered herbicides for
killing weeds.
A review of current scientific literature by
Andre Leu from the Organic Federation of
Australia found that many of these registered
chemicals have been linked to
• disruptions in the hormone, nervous, and
immune systems;
• cancers including pancreatic, colon,
lymphoma, leukaemia, breast, uterine, and
prostate; and
• auto-immune diseases such as asthma,
arthritis, and chronic fatigue syndrome.
Some examples
T
he review contained many examples of studies
that have clearly shown the damage that
agricultural chemicals are doing to human health.
We’ve included just a few examples:
1. Atrazine is one of the world’s most commonly
used herbicides. Two peer-reviewed studies
showed that levels 1,000 times lower than
currently permitted in our food and in the
environment cause severe reproductive
deformities in frogs.
2. The Report by the US President’s Cancer Panel
in 2010 stated that environmental toxins,
especially chemicals, are the main causes of
cancer, and raises particular concerns over the
exposure levels for children.
3. Four studies published in the peer-reviewed
journal Environmental Health Perspectives in
2010 and 2011 showed that prenatal exposure
to organophosphate insecticides adversely
affects the neurological development of
children and reduces their IQ.
Conversely, the review also provided more
evidence for how organic food can improve
health:
1. A study by the University of Washington found
that children who eat organic foods have
lower levels of pesticides in their bodies, and
that feeding children organic food can reduce
their exposure to pesticides to a negligible
risk.
2. The French Agency for Food Safety found in
2010 that organic foods have higher levels of
minerals and one-third more antioxidants on
average.
We learned the hard way that chemicals are not
the magic wand farmers wish they were! They’re
expensive, they damage human health and the
environment, and they cause more problems in
the long term than they solve in the short term
by destroying natural fertility, killing predators,
and upsetting the natural balance of a biodiverse
garden.
© Mt Alexander Fruit Gardens 2014
The eight keys to organic
pest control
S
ince we started our journey to organic
production, we’ve learned that weaning
yourself from chemicals can take time,
persistence, and a lot of hard work. After a lot of
experience and trial and error, we’ve worked out
the keys to organic pest and disease control.
1. Soil
Having healthy soil containing lots of
microorganisms (like bacterial, fungi, protozoa,
and nematodes); worms, ants, and other critters;
lots of nutrients; and plenty of organic matter
means your fruit trees will get all the nutrients
they need, at the right time. This means the tree’s
sap (and the fruit) will be nutrient rich and contain
complete proteins, instead of incomplete amino
acids, and this makes them very indigestible to
insects.
2. Prevention is easier than cure
Understanding the life cycle of pests and diseases
helps you figure out how and when to disrupt it,
thereby preventing it becoming a pest in the first
place.
3. Most pests have predators
The first few pests to show up in spring are often
essential in attracting the right predators to your
garden.
4. Encourage variety in your garden
to provide habitat for beneficial
insects
The more diverse your garden is, ie, the more
different types of fruit trees, other plants,
animals, insects, weeds, microbes, birds, water
sources, and micro climates you have, the more
balanced your system will become and the fewer
pests and diseases you’ll need to deal with.
5. Hygiene is important
Cleaning up fallen fruit, diseased wood, etc. is
one of the basic ways to interrupt the life cycle of
many pests and diseases, and is vitally important
in organic gardens.
6. Maintain your trees well with
nutrition, pruning and water
Making sure your fruit trees aren’t stressed gives
them the best chance of staying healthy (see the
check list on the next page).
7. Monitor your trees regularly
Keeping on eye on things, at least once a week,
avoids problems sneaking up on you. It’s easier
to nip a problem in the bud than deal with the
damage afterwards.
8. Plan your fruit tree garden
Having the right number of fruit trees—with fruit
you really love—will help you look after them
properly.
Most pests have
predators—a wasp
lays its egg in an
aphid
6
Orchard hygiene is
vital—fruit left lying
on the ground is a
disease trap
© Mt Alexander Fruit Gardens 2014
Keeping your fruit trees healthy: An overview
Avoid artificial fertilisers
One of the ways trees can end up with incomplete proteins, or free
or fragmented nutrients, is from the supply of excess nutrient, such
as nitrogen, from artificial fertilisers.
Artificial fertilisers also damage the soil. They are salts, and can
either kill the healthy soil microbes your trees need outright, or
make the soil too unfriendly for them to thrive.
For this and a whole lot of other reasons, just avoid them
altogether!
Make sure your trees have
a balanced supply of all
the nutrients they need,
especially trace elements,
in a plant-available form
Build healthy soil by
• adding a variety of organic matter from different sources, eg,
natural fertilisers such as well-rotted manures, worm castings,
good compost, mulch, and green manures;
• providing the right soil conditions to provide a happy home for
healthy soil microbes and worms, ie, air, enough moisture, and
lots of organic matter;
• if you’re making your own compost, making sure it’s diverse by
adding different types of food waste, plants, herbs, and manures;
• if you’re buying compost, changing suppliers regularly; and
• if you have a worm farm, feeding your worms a wide range of
foods so they produce diverse worm castings, including the whole
range of nutrients, to use in your garden.
Manage your tree’s water
requirements
Make sure your trees have enough water (but not too much),
especially at key times in their development
Make sure the trees have
adequate drainage
If it rains heavily, you don’t want your trees sitting in water. This
can be done either by planting the trees on mounds or swales,
putting aggie pipe in when you plant the trees, or choosing a site in
your garden that has good drainage. If you’re not sure, go out after
it rains and check the ground. Anywhere there is still a puddle when
all the other water has drained away is likely to be a spot with poor
drainage.
Grow your trees in
conditions that suit the
variety
Plants that are grown at the edge of the environment in which
they are most comfortable will be less resistant because they
will be under more stress (for example, if the rainfall is too high,
temperatures are too high or low, or you’re trying to grow tropical
trees in a temperate environment). Having said that, it’s always fun
and interesting to stretch the boundaries of where fruit is ‘supposed’
to grow, by creating micro climates.
Encourage biodiversity in
your garden—monoculture
favours the pests, diversity
favours the predators
The more different types of plants you have (including ‘weeds’), the
more habitat you are providing for beneficial insects and the less
chance the pests have to get established and do damage to your
trees. Other ways to encourage biodiversity include
• choosing plants of different heights to create different habitats;
• having water sources that are easily accessible, eg, ponds and
dams, to help attract lizards, frogs, and birds, which all play an
important part in keeping your fruit tree healthy;
• including some native plants (we prefer native food plants, but
whatever takes your fancy...); and
• making sure you have no bare ground, but good ground cover,
including fallen wood, to provide extra habitat.
Reduce the pressure from
Good orchard hygiene, like removing ‘mummies’ and getting
pathogens around your fruit diseased wood out of your fruit trees, will reduce the stress on them
trees
and help to keep them healthy.
7
© Mt Alexander Fruit Gardens 2014
Life cycles of insect pests
U
nderstanding the life cycles
of pests gives clues to how
we can control them. The more
we know about them, the more
we can be clever about finding
easy ways to interrupt their life
cycle when they’re vulnerable.
Insects go through different
life stages, and are more
vulnerable at some times than
others.
Different bugs have
different lifestyles…
I
nsects go through
metamorphosis between life
stages, which means they may
experience big changes in body
shape, diet, and habitat. There
are two main types of life cycle.
Simple metamorphosis
This is also called an ‘incomplete
life cycle’, and the main feature
is that the young look similar
to the adults. Examples of
insects in this category include
mites, grasshoppers, bugs (eg,
apple dimpling bug, long-tailed
mealybug), earwigs, and aphids.
There are three stages of
growth:
• egg
• nymph
• adult
Nymphs usually look similar
to adults only smaller and often
wingless, but they usually eat
the same food source.
Complete metamorphosis
More advanced insects
(including most of the major
pests of fruit trees) go through
a ‘complete life cycle’ which has
four stages:
• egg
• larvae
• pupae
• adult
This is important because
the larval and pupal stages
are when the insects are most
8
vulnerable to control by us! They
will also usually have a different
food source.
This group includes moths
(eg, Codling moth), weevils,
ladybirds, and parasitic wasps.
Different bugs have
different eating habits…
M
ost pest insects fall into two
broad categories, which
again can help us to come up
with a plan of attack.
Chewers
This group includes stem
borers, leaf eaters, leaf
skeletonisers and root eaters,
eg, beetles, larvae, caterpillars,
grasshoppers, crickets, ants and
millipedes. They have strong,
toothed jaws called mandibles.
Chewers are susceptible to
stomach poisons, repellents, and
to predators. They are often (but
not always) crawlers, so can be
prevented getting into your fruit
trees with a barrier, and can
also be washed off, picked off by
hand, or shaken off!
Suckers
These insects have tube-like
mouthparts called a proboscis
which is designed to penetrate
tissue. They usually feed
on plant fluids which they
tap directly from the plant’s
circulatory system (xylem and
phloem), or they might suck out
the contents of plant cells.
This group includes scale,
aphids, mealybugs, leafhoppers,
cicadas, stink bugs, Harlequin
bugs, and thrips.
Some sucking bugs feed
on other insects (these are
beneficial insects), and these
include lacewing larvae and
some flies, some mites, spiders,
and centipedes.
Plant suckers affect plants by
reducing their vigour, and may
also spread viral and bacterial
diseases.
Suckers can be smothered
with a variety of means. The
crawlers can be deterred with
barriers, other insects can be
rubbed off, physically removed
with water jets or trapped. They
tend to be very vulnerable to
predators.
Control
Our guiding principle in putting
together this guide has been
“do no harm” (though obviously
on occasion harm is done to
individual insects but mostly we
leave it up to the predators to
do this unsavoury job for us).
For both chewers and suckers,
organic pesticides are available
that will kill them, but these
should only be used as an
absolute last resort, because it’s
too easy to kill beneficial insects
that would kill the pests you’re
trying to control, and you’ll end
up doing more harm than good!
Another guiding principle
we rely on heavily is the notion
of interrupting the life cycle
when the insect is at its most
vulnerable. To give you an
overview of how this works, the
table on the next page gives an
‘at a glance’ summary of the
most common insect pests of
fruit trees, and some tips on
how you can swoop while they’re
vulnerable!
More detail on each method
is provided in The Insect Pests
chapter, where we provide
information about each insect
including a range of control
methods for that specific pest,
though of course many methods
will work on a range of pests.
© Mt Alexander Fruit Gardens 2014
Get ’em while they’re vulnerable!
Pest
Vulnerable part of life cycle Control method
Codling moth
Larvae looking for somewhere to
pupate
Provide pupating site with
cardboard
Pupae in soil
Chooks
Newly emerged female moth
Banding around tree trunk with
sticky tape
Male moth looking for mate
Mating disruption with pheromones
Larvae on leaves
Dust with drying agent
Pupae in soil
Chooks
Eggs overwintering on leaves
Smother with winter oil spray
Soft-bodied adult stage delicious to
predators
Encourage predators with a range
of white and yellow flowering
plants
Adults crawling up trunk into tree
Banding around tree trunk with
double-sided sticky tape or
horticultural glue
Adults overwintering in soil and
emerging early spring
Chooks
Carpophilus beetle
Adults looking for mature fruit to
breed in
Clean up all ripe fruit from tree
and ground
Fruit tree borer
Larvae live in holes in trunk for up
to 2 years with clear evidence of
presence of hole
Stick a bit of wire in the hole and
wiggle it!
Fruit fly
Newly hatched adults needing to find Trap and kill with protein-based
protein source before they can mate trap
Pear and cherry slug
Aphids
Earwigs and garden
weevils
Grasshoppers
9
Mated females needing ripe fruit to
lay eggs
Clean up all ripe fruit from tree
and ground
Overwintering as eggs
Smother eggs with winter oil
© Mt Alexander Fruit Gardens 2014
Monitoring for insect pests
G
etting to know your fruit trees will help you
respond quickly to attack from pests or
diseases, and may help you save your crop! The
best way to monitor your fruit trees is to visit
them often—say once a week—and check them
out. A quick 5 minute check is all you need to stay
on top of the game!
Most pests are active throughout spring and
summer, often going through several complete
life cycles in that time—the number of cycles
will depend on several variables, including
your climate, the number of predators, and the
weather in any given year. In autumn/fall many of
the pests make preparations to survive the winter,
and most pests are dormant in winter.
How to monitor your trees
A
ssess the overall health of the tree—do the
limbs and leaves look generally healthy? If the
tree still has fruit on it, look at individual pieces
of fruit and check for damage, particularly from
earwigs, garden weevils, Fruit fly, and Codling
moth. Check the leaves for sign of pear and
cherry slug, aphids, or anything else that might
be eating them.
If you’re not sure what is causing the damage,
carefully look around the tree and fruit for any
evidence you can find—particularly fresh damage
to leaves, or insects on the tree. Check inside
curled leaves, and in dark places on the tree
(some insects are nocturnal and will hide during
the day). Use the photos in this book to help you
identify the problem.
You can also take a photo and post it to the
forum on our website, and Grow Great Fruit
members can also post specific questions and
photos directly to us for some personalised help.
earwigs (and then removing as many pests as
possible from the tree), baiting or using fruit
shields for fruit fly.
3. If the fruit will still be usable when it ripens
and is not creating a further problem, leave it
on the tree and do nothing.
4. If you diagnose or suspect a nutritional
problem with the tree, you’ll need to pay
attention to the nutritional health of your tree,
starting with the soil.
It’s a great idea to start keeping notes on each of
your fruit trees (for members of the Grow Great
Fruit program we provide a Fruit Tree Diary for
this purpose). Note the date, your diagnosis of
the problem, and any action you took. This can be
helpful in preventing problems from recurring next
spring.
And remember, DON’T PANIC. In a healthy
garden, pests are inevitably followed by
predators, and it’s important not to rush in and
spray a pest—in fact, it’s very easy to do more
harm than good!
It’s easy to confuse the pest with the predator,
and if you spray what you think is causing the
damage, you might be killing your saviour.
It can also take some time for the predators
to show up. One year we had very bad pear and
cherry slug in the pear, cherry, and plum trees,
which we monitored closely throughout the
summer, ready to spray an organic insecticide if
we needed to save the trees. Luckily the damage
didn’t get that bad and we didn’t have to spray,
and by the next summer the predators had built
up in sufficient numbers to take care of the
Taking action
D
iagnosing a problem in your fruit tree can help
you decide what to do next—which may be
one (or more) of these four options:
1. Damaged fruit should be removed from the
tree and destroyed as soon as you notice
pest damage, if doing so will help to disrupt
the life cycle of the pest. This can stop the
pest numbers from building up, and can help
reduce the problem the following year. This
applies especially to Fruit fly and Codling
moth.
2. Take preventive action to prevent further
damage to any remaining fruit on the tree,
eg, netting the tree to prevent bird damage,
putting a barrier (eg, double-sided tape or
horticultural glue) around the trunk of the tree
to prevent damage from garden weevils or
10
Monitoring for aphids
© Mt Alexander Fruit Gardens 2014
problem for us (and much more efficiently than
we could have). If the tree is not suffering too
much damage, it’s worth cultivating patience and
keeping a close watch.
What’s normal: how should my trees
look throughout the year?
Winter
Deciduous trees by definition lose their leaves
every year and become dormant over winter.
This means the tree is not photosynthesising or
growing. The roots have also stopped working, so
the tree is not using any water from the soil.
Spring
You can tell your trees are coming out of
dormancy when their buds start swelling. Stone
fruit trees (cherries, apricots, peaches, nectarines
and plums) all start flowering first, then the
leaves appear. It’s the reverse for apples and
pears, which produce leaves first then flowers.
All the energy for this first flush of growth and
flowering comes from stored energy in the tree’s
buds, shoots, and bark.
At the same time as the buds start swelling,
the fine root hairs start to grow, letting the trees
begin to extract the nutrition they need to keep
growing from the soil.
The flowers shrivel and fall off. If they have
been fertilised, the flowers leave behind a tiny
fruit that then starts to develop. If they weren’t
fertilised, the entire flower falls off, and just
leaves remain.
The leaves unfurl and grow, and some of the
leaf buds will start to elongate to make new
shoots. In healthy trees this can happen very
quickly, and it’s not uncommon to see several
centimetres of new growth in the first month
of spring. New leaves are often orange or red,
possibly with a dark margin, and then gradually
turn to green as they grow. New leaves usually
continue to grow throughout spring.
As spring progresses, the tiny fruits start to
enlarge and grow, fuelled now by photosynthesis
You don’t need to touch
spiders—just like them!
11
through the leaves converting sunlight into
sugars.
Summer
Shoot growth starts to slow down as the summer
temperatures increase, particularly if a tree has
a lot of fruit. Fruit continues to grow until it’s ripe
and ready to harvest, though different fruits grow
at different rates. Most fruit grows fastest in early
spring, and then again in the 6 weeks before it
ripens, with relatively slow growth in between.
Autumn/Fall
In early autumn trees should still be covered with
leaves, and the leaves of most varieties should
be large, medium-to-dark green, and healthy
looking. It’s completely normal for the leaves
to have accumulated some damage throughout
summer; they may have some discolouration
or holes as a result of physical damage or
environmental conditions.
Once the fruit has been picked, the tree may
begin to lose its leaves, or the leaves may go
yellow, orange, or red before starting to fall. This
is normal and can sometimes happen quite quickly
after all the fruit has been picked. The leaves have
essentially done their job (of converting sunlight
into sugar in the fruit) for the year, and the tree
no longer needs them, so it starts to withdraw the
nutrients from the leaves (hence the change of
colour), and go into shutdown mode for winter.
Accumulated damage
It’s very normal for fruit trees to start
accumulating some damage to their leaves each
year, starting in spring or summer, and in most
cases the tree will bear this very well without any
(or much) loss of function. The damage might be
caused by insects pests, larger pests, disease,
nutritional problems, environmental effects like
heatwaves, or physical damage.
Part of the reason we encourage regular
monitoring of fruit trees, and getting to know
what’s ‘normal’, is to encourage gardeners to be
able to tell the difference between this normal
level of damage and more serious issues that
need treatment.
Similarly, the bark and the structure of your
tree will usually accumulate some damage over
its lifetime, from physical damage (getting a
bit close with the mower anyone?), animals,
branches breaking for various reasons, or disease.
Some of this can be repaired (eg, with pruning)
but quite a lot can be tolerated, even disease
issues like gummosis or fungal disease. Let your
guide be whether or not the tree is still growing
well, putting out new shoots; growing large,
glossy healthy leaves (at least at the beginning
of spring); and, most importantly, bearing
consistent, healthy crops of fruit!
It’s time to let go of our desire for ‘perfect’
trees or fruit and focus on the really important
stuff, like getting a crop of delicious fruit, every
year!
© Mt Alexander Fruit Gardens 2014
Fruit tree hygiene
I
n an organic garden or orchard, hygiene is the
second line of defence against all pests and
diseases (soil is the first!). Really, it’s just a grand
way of describing the practice of keeping the area
in and around your fruit trees clean, and free of
the conditions that help pests and diseases to
build up. It’s NOT about creating a manicured
garden, because at the same time it’s a great
idea to encourage lots of different types of plants
to grow near and under your fruit trees, which
doesn’t always result in a neat-looking garden!
The first rule for management of almost every
pest of fruit trees is to dispose of infected fruit.
Most pests have very clever ways of ensuring
their ongoing survival in your garden! Luckily,
we’re smarter than they are, and can come up
with ways to disrupt their life cycle, usually by
removing the source of the ongoing infection, and
often while they are in their dormant phase.
10 Key Hygiene Rules
1. Remove all fruit from the trees and the ground
under the trees. This should be done as part
of the routine monitoring during the fruit
season, and after the season before winter.
This not only removes the eggs, food source,
and breeding ground of various pests, but
has the added benefit of helping to prevent
disease as well by removing fungal spores and
bacteria.
2. Remove dead and diseased wood when you’re
pruning. The wood needs to be treated in
Remove any dead wood
12
when pruning
some way before it can be used again in the
soil, either by chipping and composting, using
as litter in the chook pen, or burying away
from the fruit trees so it can rot safely without
spreading disease.
3. Keep nasty, invasive, and/or unpleasant
weeds under control. Invasive weeds like
paspalum and blackberry can reduce the
biodiversity in your garden, and directly affect
the health of your fruit trees by choking out
the plants you want.
4. Replace non-useful weeds with helpful or
companion plants in the environment around
your fruit trees. This encourages biodiversity
and provides habitat for predator insects that
help to keep pests under control. It’s great to
include some plants with deep taproots that
will “mine” nutrients from deep in the soil and
bring them up to make them available to your
trees. You can also make best use of your
space and increase the yield from your garden
by growing other food-producing plants under
your fruit trees.
5. Plan for gluts. If you can’t manage to pick,
use, cook, or give away all the fruit you grow,
it might be time to replace your existing fruit
trees with more useful varieties.
6. Recognise there is no waste and find a way
to return everything the fruit tree produces
to the soil, after it’s been ‘cleansed’ by being
put through compost, worms, and/or other
animals first.
Picking up and disposing of
© MtisAlexander
Fruit Gardens 2014
fallen and rotten fruit
vital
7. Make sure air can circulate freely around the
trees. Careful pruning, weed removal, grass
cutting, and removing suckers all help with
this, allowing your pest control methods to be
more effective.
8. Water the ground, not the tree. Sprinklers
that get the leaves wet are not a good idea
as they can create the ideal conditions for a
fungal outbreak.
9. Encourage biodiversity under the soil as well
as on top of it. Worms, bacteria, and fungi
(as well as lots of other microbes) can all
be encouraged by using compost tea, worm
juice, or seaweed preparations, as well as
making sure there is a constant supply of
organic matter for them to eat.
10. Remove feral or unwanted fruit trees. If
a tree is not of use to you, it’s much better
to either remove it altogether, or graft it to a
more suitable variety that will be valued and
used.
Dealing with gluts of fruit
O
ne of the ‘problems’ we can create for
ourselves when we start growing our own
fruit is creating an excess. This might be because
there’s too much fruit ripe at the same time, the
family doesn’t happen to like a particular fruit, or
you just might not have time to pick it all.
We’re all about turning problems into
opportunities, so here’s some different ways to
think about it:
• Who else could use your surplus fruit?
Neighbours, food-swap programs, food share,
local schools, charities, community kitchens...
are there any in your area? If you don’t know,
find out through your local government.
Many farmers’ markets run a food swap, and
there are several active online food-swap
communities that may be able to help with
what’s available in your area.
• If there’s no food swap in your area,
consider starting one! Check out the Growing
Abundance program for a great communityled model of making the most of fruit gluts.
• Do you have a friend or neighbour who would
appreciate being able to gather the fallen fruit
for their animals? Animal shelters, breeders,
and local farmers are often glad to gather or
receive surplus produce.
• Could you (or someone else) process the
glut of fruit for use later in the year? Do you
have vague memories of your mother (or
grandmother) bottling or making jam, but
have never done it yourself? It’s really easy
when you know how, and we provide stepby-step instructions each month in the Grow
Great Fruit program.
• Could the tree be replaced or grafted to
produce a different type of fruit that your
family prefers? Make sure every fruit tree and
plant in your garden is pulling its weight!
13
Bottling is one
of the many
ways of dealing
with a glut
© Mt Alexander Fruit Gardens 2014
The insect pests
Aphids
Pest of: apples, pears, cherries,
peaches, nectarines, plums
T
here are four main types of aphids
that are pests of fruit trees—green and
black peach aphids, black cherry aphids,
and woolly aphids (only in apples). The
good news is that all aphids have plenty
of predators, and even if you have a
really bad outbreak, it’s not too hard to
get them under control. One of the things
they have in common is their life cycle,
allowing us to interrupt it at the same
place, by smothering their eggs in winter
with a winter dormant spray of mineral oil.
Aphids are ‘sucker’ type pests, with
piercing mouthparts. They have wings
that are membranous and transparent
at the tips, but thick and leathery at the
base. There are hundreds of species of
aphids—in Australia, for example, there
are about 50 native species, though most
common species (and all the ones that
have become troublesome pests) were
introduced. They feed by sucking nutrients
out of the tree sap, and while they’re at
it they can also transmit plant diseases,
particularly viruses.
They’re small (only about 2 mm long),
pear-shaped, soft-bodied insects that live
in colonies. In most species females lay
eggs but they may also give birth to live
young and sometimes can do this without
mating (called parthenogenesis).
One of their secrets to their success is
that they secrete honeydew (the waste
from the sap they ingest, after they’ve
extracted nitrogen and other nutrients
from it) through short tubes on their
abdomen, and this can cause sooty mould
to grow on the plant. Ants feed on the
honeydew, and in return protect the
aphids from their natural enemies—in
effect they ‘farm’ the aphids.
Aphids are attracted to plants that are
fed artificial fertilisers, especially highnitrogen fertiliser—another great reason
to avoid fertilisers! In balanced, organic
gardens that rely on healthy soil instead
of artificial fertiliser, aphids are rarely a
problem, in fact they are usually only a
troublesome pest if their many natural
predators are being killed by pesticides.
14
Black peach aphid
Green and black peach aphid:
Usually the first sign of aphids is leaves looking stunted
and curling in on themselves. On inspection, a colony of
aphids will be found inside the curled-up leaf. Affected
leaves may turn yellow, shrivel, and fall, and laterals can
die. Green peach aphid nymphs and wingless adults are
distinctly green and around 2 mm long.
Green peach aphid
© Mt Alexander Fruit Gardens 2014
Life cycle
Wingless adults can appear on your trees quite
early in spring, from budswell onwards. Later in
the season you might also start to see winged
adults.
Aphids lay eggs on leaves and branches at the
end of summer, and these overwinter as eggs
around the base of buds. Woolly aphids move
down to root systems of apple trees to overwinter.
Monitoring
In your weekly visit to your fruit trees, you’ll
usually notice any aphid infestations quite quickly.
Just observe them at first, and start monitoring
for predators because they’ll often turn up
relatively quickly and start controlling the aphids
for you.
If you detect the early stages of a black cherry
aphid infestation, it’s easy to prune or snap off
the bunch of affected leaves and destroy them, to
prevent the aphids spreading.
Usually the first thing you’ll notice is that
young tip growth (ie, the leaves at the ends of
the branches) becomes deformed and leaves start
curling in on themselves. Green and black peach
aphids colonise the undersides of leaves on peach
and nectarine trees, causing them to curl in. Black
cherry aphids will be seen as a messy black mass
on the ends of branches, and woolly aphids are
clearly visible because of the white waxy coating
they exude. It’s quite easy to see aphids in most
cases, though if you haven’t monitored regularly
and come across an infestation that’s been there
for a while, the aphids may already be dead,
A
leaving only deformed leaves behind. Check very
carefully inside the leaves—use a magnifying glass
if you have one—and you’ll often see the dead,
dried up bodies of the aphids that have been
predated by other insects. They’re very small,
flaky and become pale and white as they dry out.
Prevention and treatment
Aphids have many predators, including birds,
ladybirds (and their larvae), hover flies, lacewings,
young mantids, predatory mites, spiders, earwigs
and many species of wasp.
The first and most important form of
prevention is to stop spraying any insecticides
in your garden! Aphids are a classic ‘indicator’
species—they have so many predators that will
usually keep them under control that a severe
aphid outbreak really is a sign that there is not
enough biodiversity in your garden. Even natural
insecticides (like pyrethrum, or eco-oil) can
indiscriminately kill predator insects and should be
used with extreme caution.
If you’ve had a bad outbreak, or are having
regular outbreaks each year that don’t seem to
be getting any better, you can spray a mineral oil
(also called winter oil, or white oil) on your trees
either while they are dormant in winter, or in
very early spring (if you’re using a copper spray,
eg, to prevent leaf curl or blossom blight, it can
be combined with that spray). The oil smothers
and kills the eggs that are overwintering on the
tree. This can be a useful tool to help get severe
aphid outbreaks under control, but it’s common
for aphid problems to slowly disappear over the
B
C
Woolly aphid:
Mainly attacks apples, and usually found in
cracks in bark, pruning scars, on new growth,
or on suckers coming up at the base of the tree.
Infestations can spread to fruit, covering the fruit
with a sticky black mess. They prefer the shade,
and are usually found on sheltered parts of trees
and on the undersides of lateral growth.
15
Black aphid and ant:
Ants feed on the honeydew produced by aphids,
and will often be seen in close association, as they
tend the aphids and protect them from predators.
© Mt Alexander Fruit Gardens 2014
years as you improve your soil health, tree health
and biodiversity, so spraying should become less
necessary as time goes on.
Here’s a few more tactics:
• Maintain tree health, soil health, and
biodiversity (ie, lots of different types of fruit
trees, shrubs, herbs, weeds, insect species,
birds, etc. in your garden).
• Plant or allow yellow- and white-flowering
plants under your trees (even weeds) to
attract beneficial insects.
• Put barrier around tree trunks with doublesided sticky tape or horticultural glue to
prevent ants climbing the tree and ‘farming’
the aphids.
• Wash aphids off with a strong jet of water or
soapy water.
• Rub off with gloved hands, or rag dipped in
rubbing alcohol.
• Use organic home remedy spray (see p. 41).
• As a last resort for really severe infestations
you can spot spray with an organic pesticide
like eco-oil or pyrethrum, but be sure to read
the label carefully, and only spray the aphid
colonies rather than the whole tree, to make
sure you don’t spray the predators, as this will
just make the problem worse.
• And the last strategy is—“Don’t panic!”
Usually the first aphids of the season are
rapidly followed by an explosion of predators
that will eat them. Encourage predators by
NOT using any insecticides or poisons in your
garden, and by having a wide variety of plants
to attract them.
Similar pests
Cowpea aphid and Cotton or Melon aphid.
Cowpea aphid are green, and will quickly colonise
fruit trees once they’ve settled. They produce
honeydew. Cotton or Melon aphids are blackish
green, and the nymphs range from green to
orange. They also produce honeydew. All the
above information applies to these aphids also.
Typical aphid damage
A tree recovering from aphid attack
Dead aphids inside a curled leaf
16
© Mt Alexander Fruit Gardens 2014
Carpophilus beetle
Pest of: apricots, peaches,
nectarines.
A
lso called dried fruit beetles, there are at least
12 species of carpophilus beetle in Australia.
They can be either brown or black, and are tiny,
only 2-3 mm long—about as big as a mouse poo!
Unfortunately they are attracted to, and
penetrate, ripening fruit to lay their eggs. The
holes they create are tiny and almost unnoticeable
(and the eggs and larvae developing in the fruit
are also tiny and hard to notice) but the real
damage arises because they are carriers of brown
rot (Monilinia spp.), which often starts at the
entry point.
They are good fliers, and can travel more than
4 kilometres to find a food source. In some fruit
growing areas in Australia, carpophilus beetles are
a serious pest of ripening stone fruit, particularly
apricots, peaches, and nectarines.
Life cycle:
Carpophilus beetle overwinters as adults, mature
larvae, or pupae in rotting fruit left on or under
the tree, in the soil, in cracks and crevices in the
bark of the tree, or even in bits of wood lying
around near where there has been rotting fruit.
They will also use rotting fruit that is not their
normal host in summer (eg, citrus or apples) as a
host over winter.
Adults become active in early spring once the
temperature reaches 18°C. They mate, and lay
eggs in ripening fruit on the tree, or decaying fruit
on the tree or the ground. Each female can lay up
to 1,000 eggs! Eggs hatch after between 1 and
4 days, and larvae develop in fruit for between 4
and 14 days, then exit fruit and pupate in soil.
Adults will then hatch and start a new
generation. The whole life cycle from egg to adult
will take 47–65 days at 20°C, but much less time
in warmer weather—only 14–18 days at 32°C—so
there will be many more generations in a warm
year.
Carpophilus beetle and damage in an apricot
17
Carpophilus beetle
In cooler areas, the population will peak in late
spring/early summer (November–December in
the southern hemisphere), but in a wetter than
normal season there can be another population
peak in late summer.
Adult beetles are attracted to the smell of
rotting fruit up to 500 metres away, and will
fly long distances to find food, which means
populations can spread over a large distance.
Monitoring
It’s easiest to monitor your fruit (particularly
when you start picking) than trying to monitor the
insects. For a start, they’re tiny and hard to spot,
and secondly they’re hard to prevent because
they fly.
They enter the fruit by chewing holes in the
skin around the stem or in sutures, though they
can also enter through holes that have been
caused by something else (e.g., bird pecks).
Fruit with carpophilus beetle entry holes near
the stem end are very vulnerable to developing
brown rot, and shouldn’t be stored with
undamaged fruit. Conversely, if you’re noticing
fruit with spots of brown rot developing, check
carefully for holes that might indicate carpophilus
beetle entry, to help identify whether you have
the beetles.
© Mt Alexander Fruit Gardens 2014
Hygiene is important, so pick up all
fallen fruit and use or dispose of
Prevention and treatment
• Orchard hygiene is really important in
breaking their life cycle because the adults
lay eggs in decaying fruit on the tree or
the ground. Therefore, remove all the fruit
from your tree and clear the ground under
your tree at the end of each season to
remove their habitat.
• They go through several generations per
season, so if any fruit falls under your tree
during the season make sure you pick it
up and dispose of it, because adult beetles
can be attracted to it from more than 500
m away.
• Make sure you clean up all the fruit from
the tree (and in the tree) at the end of the
season.
• Allow chooks to scratch in soil around
trees to clean up pupae, particularly over
autumn/fall and winter.
• A wet autumn and winter are likely to lead
to a bigger carpophilus beetle population
the following spring, so monitor more
carefully.
• Early season crops are more vulnerable to
attack because populations of the beetle
are at their peak during late spring to midsummer.
• Trap beetles using an attractant trap.
Make a carpophilus beetle trap
Make a simple carpophilus beetle trap with a plastic bottle containing 200 ml of pure apple juice and a
small amount of bakers’ yeast (1 gm) for fermentation to mimic rotting fruit. Hang the trap about 1.5
m from the ground on a tree branch. Place it on the upwind side of the tree. You can also use a jar and
coloured cardboard (see photo of fruit fly trap on p. 25).
A couple of tips: fruit-eating insects are often attracted to red or yellow, so use a plastic bottle with a
red or yellow lid, and make the entry hole in the lid.
Most of the beetles should drown in the trap, but you can add a splash of pyrethrum or some other
organic insecticide to make sure the job gets done properly! Be sure to monitor your trap every day or
two to make sure you don’t accidentally kill too many nontarget insects.
Finish your trap with a layer of vegetable oil on top of the water to prevent insects escaping, and to
stop mosquitos breeding in the water.
Fresh baits work best, so refresh the contents every week.
18
© Mt Alexander Fruit Gardens 2014
A
Codling moth
Pest of: apples, pears, and nashis
T
hese are the classic ‘grub in the apple’ pest!
Not the moths themselves, but their larvae,
which burrow into the middle of apples!
Codling moths are a very boring brown colour
and are quite small, with only a 15 mm wing
span, so it’s unlikely you’ll notice them. If you do
spot a small brown moth on your fruit tree, you’ll
know it’s a Codling moth by the distinctive copper
coloured strip at the end of the wings.
Larvae, on the other hand, are easy to spot—
inside your apples! They’re cream coloured, about
20 mm long when fully grown, with dark brown
head parts. Infected apples will always have
a grub inside, unless they’ve already finished
maturing and left the apple to pupate.
They usually only affect apples and pears,
though you’ll occasionally see them on quinces,
and occasionally on a walnut, plum, or peach.
Life cycle
The larvae pupate inside their cocoons and
emerge as adult moths in early spring (from
mid-September to early October in the southern
hemisphere). The moths are active for only a few
hours before and after sunset, and they mate
when sunset temperatures are 160C or higher, and
the air is calm.
After mating, each female deposits 30–70 tiny,
disc shaped eggs singly on fruit or leaves. After
the eggs hatch, young larvae find fruit, and then
tunnel into it to the core, where they eat the
seeds. Damaged fruit might drop to the ground,
but will often keep hanging in the trees.
After completing development the larvae leave
the fruit (you’ll see separate entrance and exit
holes in fruit) and drop from the trees to search
out pupation sites and continue the life cycle in
the soil or on debris under the tree; some crawl
back up the tree to pupate in bark crevices.
They usually go through 2–3 cycles per year
and then overwinter on trees under bark, in litter
trapped in the tree, or in soil at the base of the
tree.
Codling moth larva
them as they enter the apple).
If there’s more than one hole in the apple, then
either it’s separate entry and exit holes—in other
words the horse has already bolted—or there’s
more than one grub in your apple!
Prevention and treatment
It’s much easier to prevent Codling moth taking
up residence in your trees than to control an
established population, so vigilance is very
worthwhile if you’re starting out with new apple
trees in your garden.
Check your trees every week (starting at 6–8
weeks after full bloom or when the temperature
reaches 160C at dusk), and remove and destroy
any infected fruit, including any fallen fruit. In
removing the fruit, it’s important to make sure the
larva inside is actually destroyed—don’t just throw
it in the chook pen or compost pile; squash it first
or use some other way to destroy the larvae (see
various methods for destroying larvae under Fruit
fly).
B
Monitoring
A warm, dry spring speeds the development of
eggs and larvae and can lead to more generations
occurring during the season (usually two or
three). Warm conditions in late summer increase
the risk of late infestation.
When you check your apple and pear trees
each week, carefully look at each piece of fruit,
and particularly between pieces of fruit that are
touching. You’ll know you have Codling moth if
you see a distinct round hole on the surface of
the fruit, with brown frass emerging from the
hole (frass is sawdust type material, which is the
chewed up apple flesh the larvae push behind
19
Codling
damage
© Mt Alexander
Fruit moth
Gardens
2014
A
If there’s a lot of apple trees in gardens
nearby, it’s fantastic to have a neighbourhood
Codling moth strategy, to prevent constant reinfection. If a large enough area is being treated
(ie, if you have a large garden or small orchard,
or where a group of neighbours can get together
to treat this pest), the most effective prevention
is called ‘mating disruption’. This uses pheromone
dispensers (which you can buy from farm supply
shops) to emit massive amounts of pheromones
(female hormone) into the air above the trees.
The pheromones confuse male moths which are
then unable to find the females to mate—mean,
but effective! They work well, but must be used
on a minimum area of 1 hectare, and depending
on the supplier can cost up to $500/ha. (Warning:
don’t be tempted to use mating disruption on
a smaller area than suggested here—using it
wrongly has been known to increase the amount
of damage caused by Codling moth!)
It’s also possible to buy pheromone-infused
codling moth traps, intended as a monitoring tool
to indicate when moths are present (these are
used mainly by chemical orchards to know when
to spray). On a small scale, they can be very
useful in helping to control moth populations. One
trap is usually enough for 6-8 trees, and lasts for
4-6 weeks (though the more traps you have, the
more moths you may catch). This method isn’t
likely to work on its own, but can be a useful part
of your overall strategy, particularly for isolated
trees.
Strategies for smaller gardens:
• Remove bark, twigs, and litter from the forks
of your apple trees to reduce hiding places for
cocoons.
• Encourage natural predators of Codling moth
such as Trichogramma wasp by not using
insecticides (even pyrethrum must be used
with extreme caution so as not to kill the
predators) and providing habitat such as
legumes.
• Wrap corrugated cardboard or hessian around
20
•
•
•
•
•
•
the trunk
of your
apple trees
throughout
summer
and
autumn/fall
to provide
Frass at a codling
sites for
moth larva exit hole
the larvae
to make
cocoons. The traps should be replaced every
3-4 weeks, and old ones burned. To increase
the effectiveness of this technique you can
provide extra bands around individual limbs,
particularly on apple trees that have rough
bark that provides lots of alternative pupation
sites.
Put a band of horticultural glue or doublesided tape around the tree trunks in spring
to prevent the movement of newly hatched
female moths from the ground into the tree.
The moths can fly when they hatch, but some
will flutter up the trunks of the trees and you
may be lucky enough to catch a few.
Nasturtiums and wormwood under tree are
said to help repel the moths (but this is
unproven).
Let chooks or other poultry forage under your
fruit trees, particularly in winter, to help to
remove larvae from the soil.
Use exclusion bags to protect individual fruit.
(p. 21).
Make a home-made trap (as opposed to the
pheromone traps mentioned above that you
can buy) using the recipe on p. 24.
Early maturing varieties of apple tend to be
less susceptible to Codling moth.
Similar pests:
Light brown apple moth (LBAM), Oriental fruit
moth (OFM), and Painted apple moth (PAM)
are all similar-looking moths that you may see
around your fruit trees. LBAM may do minor to
moderate damage to your fruit trees
B
(mainly apples), but rather than the
larvae developing inside the fruit, it
usually develops in webbing between
two pieces of fruit, or on leaves.
Thinning fruit back to single pieces
is a useful preventive strategy. OFM
tend to affect mainly peaches and
nectarines, and larvae may burrow
into the fruit; the entry site will
usually be marked by gum. As for
Carpophilus beetle, the damage
caused by the larvae will often cause
a brown rot infection at the site.
PAM is much less common, and has
distinctly hairy larvae (caterpillars)
which can cause a rash if you handle
them. Minor damage to fruit can be
caused by the larvae grazing on the
surface of the fruit.
Adult codling moth
© Mt Alexander Fruit Gardens 2014
Protecting fruit by bagging it
One of the more intensive methods of protecting
your fruit—bagging—is the most reliable method
of preventing damage by insects such as Codling
moth and Fruit fly. You can either buy a range of
bags commercially, or make your own from paper
or cloth. It’s time consuming and works best on
smaller trees, or trees with a lighter crop, but
gives you some guarantee of getting edible fruit
in return for your effort! It’s also a useful tool if
you’re launching an all-out attack on trying to
clean up a Codling moth infestation, for example
(along with a range of other methods).
A simple (and cheap) way is to use ordinary
paper lunch bags. Cut a small slit in the sealed
end of the bag, slip it over the piece of fruit while
it’s still very small, then staple the open end
shut. You’ll need to thin bunches of fruit back to
individual pieces of fruit first, but that’s a good
practice to be following anyway. If the task seems
too daunting, just bag as many pieces of fruit as
you can manage, then either closely monitor the
rest of the crop or pull it off to reduce sites where
the insects can continue their life cycle.
Another really easy way to is to use old
stockings as a sleeve that you can just slip over
the fruit, tying off at both ends with a rubber
band, twist tie, or string to seal it. This works
well for Codling moth, but Fruit fly might still be
able to sting through the material. (Also, who
wears stockings or pantihose these days? It’s a
lot harder to get old ones than it used to be!) You
A
21
can buy purpose-made nylon fruit socks, but at
about $3 each it may be more cost-effective to
buy cheap pantihose and chop them into lengths.
The advantage of this type of cover is you can put
them on easily when the fruit is small, and they’ll
expand as the fruit grows.
If you’re bagging bunches of fruit, use pieces
of paper, waxed paper, or light cloth and use twist
ties or string to tie them in place. Old pillow cases
are very useful for the purpose (you may be able
to pick these up cheaply at charity shops). Check
the integrity of the bags when you do your weekly
monitoring; the paper ones in particular may need
replacing after substantial rain.
While very effective, bagging also has several
drawbacks:
1. The fruit doesn’t colour as well. You can
remove the bags a few days before you plan
to pick and it may colour up, but you will also
be exposing the fruit, while it’s ripe, to various
predators.
2. Bags may reduce bird damage but will not
protect against possums or fruit bats.
3. Depending on the material you use, fungicides
and foliar nutrition sprays may not get as
good coverage on the fruit. Humidity around
the fruit may also increase, leading to a
higher risk of fungal disease. Using the more
porous materials, that allow rapid drying after
rain, will reduce these problems.
© Mtexclusion
Alexanderbags
Fruit Gardens 2014
Pillowcases and mesh bags both make effective
Earwigs
Pest of: cherries, apricots, peaches,
nectarines
E
arwigs can be horribly destructive to fruit,
particularly small, soft-skinned fruit like
cherries, apricots, peaches, and nectarines.
They are rarely a problem in plums and can
even be of benefit in apples and pears, where
they are predators of codling moth eggs, snails,
and woolly aphids.
European earwigs are a pest all over the world.
In Australia, we also have a native earwig which is
a useful predator.
Earwigs are nocturnal and hide during the day
in a dark place, which might be inside damaged
fruit, under leaves, under loose bark, or in debris
in or under the tree. One of their favourite spots
to lurk is in the dark spaces between pieces
of fruit, which is a great reason to thin your
fruit (other than cherries) so no two pieces are
touching, thereby removing earwig habitat.
Life cycle
Earwigs have an incomplete life cycle, which
means adults lay eggs, which hatch into nymphs,
and the nymphs mature into adults, moulting
(losing their skin) four times as they grow.
Adults live for 1 year and can overwinter in the
soil, though many die during winter. The survivors
are mainly females, which then die in the summer
after rearing their young.
Females lay up to 60 round eggs in small nests
in the top 5 cm of soil, and the mother tends the
young in the nest for the first 2 weeks, before
they leave the nest. A small percentage of females
lay a second batch of eggs in the same year.
Earwig peach party!
Monitoring
The main damage they cause is directly to the
fruit, so monitor apricots, peaches, nectarines,
and cherries, particularly the fruit closest to the
ground and towards the centre of the tree, where
damage is more likely to occur.
If you’re planning to put a barrier around the
trunk of the tree (see below), it’s much better
to do it before you see any damage to the fruit,
preferably during early to mid-spring when the
adults are likely to emerge. Once fruit damage is
occurring the earwigs are already in the trees and
it can be very hard to dislodge them.
A
Prevent earwig damage
Typical earwig damage
22
Adult earwig on a leaf
© Mt Alexander Fruit Gardens 2014
Prevention and treatment
• Predators include birds, lizards,
and nematodes, so provide diverse
habitat!
• The easiest way to prevent these
walking insects is with a sticky
barrier around the trunk of your
tree. This can either be horticultural
glue, or some kind of sticky tape.
We use double-sided sticky tape
that is sold as a form of insect trap.
o If you’re relying on a band
around your tree trunk to
prevent earwigs getting into the
A folded piece of poly pipe makes an effective earwig
tree, keep the grass cut around
trap
the tree to make sure you’re
dark places for shelter during the day, traps
not providing easy access with
can also be made either from rolled up
an insect ‘ladder’.
newspapers (held with a rubber band), or a
o Put the bands as high as possible in the
30 cm piece of poly pipe folded in half and
tree—ideally above irrigation pipes, grass
held together either with a piece of twine
or anything else that might be close to
or a rubber band. Place the traps at the
the tree, but below the fruit (obviously)
base of your trees, and empty them each
o Put the bands on early! Earwigs can
morning into a bucket of water to drown the
start moving very early in spring (or late
insects. These traps will catch any insects on
winter) and can take up residency in the
the ground, or those that descend from the
tree before it has even finished flowering.
tree during the day, but be aware that some
Once they’re in the tree, it’s a bugger
insects will be spending the day hiding in the
getting rid of them, so it’s much easier to
tree. Shaking each branch vigorously will
prevent them early on in the season.
dislodge a certain amount of the insects, but
• Traditionally growers have used petroleum
not all of them—it’s amazing how tightly they
grease, but this can damage the tree. If it’s
can hold on!
all you have available, wrap a layer of cling
• Poultry, such as chickens, turkeys, and
wrap tightly around the trunk first and put the
guinea fowl, love to eat both garden weevils
sticky stuff on it.
and earwigs. A population of 50 birds to the
• Traps can be made from containers of beer,
hectare can be enough to really help to keep
buried in the ground so the opening is level
them under control.
with the ground, and the insects will fall in
and drown.
• Because earwigs are nocturnal and seek
Earwigs prefer dark places during the day
23
Earwig and damage in an apricot
© Mt Alexander Fruit Gardens 2014
Fruit fly
Pests of: all fruit and vegetables
F
ruit fly is a problem pest in many parts of the
world, and there are many different species
involved. The main pest in Australia is Bactrocera
tryoni, or Queensland fruit fly, which is found
in parts of Queensland, NSW, Victoria, and the
Northern Territory. Another serious fruit fly pest is
the Mediterranean fruit fly.
Unfortunately the range of Queensland fruit fly
is expanding rapidly as a result of climate change,
and flies are being found in regions they were
previously not thought to be able to survive. In
recent years fruit flies have been found near our
place in central Victoria (Australia) for the first
time and, while they are not a problem yet, we
are taking early preventive action before they turn
up in numbers.
The flies lay their eggs in a very wide range of
produce (including most types of fruit), and the
larvae hatch and eat the fruit. A tiny ‘sting’ is the
only visible sign on the outside of the fruit that it
has been attacked—until you open it up and find it
full of larvae!
Life Cycle
The female lays up to 20 eggs into ripening fruit,
then the eggs hatch in about 2-4 days. The larvae
feed on the flesh of the fruit, moving into the
centre, which causes the fruit to prematurely
ripen and rot, and usually fall to the ground.
Mature larvae leave the fruit and burrow into
the soil to pupate. A key part
of the life cycle is that adult
flies emerge from the ground
(this can take as little as 7
days in hot weather), mate,
and the cycle starts again!
Adults need to feed on protein
before their eggs will mature.
females having access to your fruit.
• Collect and destroy all fruit from your garden
(whether infested with fruit fly or not) to
prevent and break the fruit fly breeding cycle
in your garden.
• Use a bait containing spinosad, an organically
allowed insecticide made from a naturally
occurring bacterium species. In Australia
one commonly available product is called
Naturalure, which is an effective, organic and
relatively cheap prevention method that works
against all species of fruit fly. Naturalure is
protein based and attracts and kills the adults
before they mate.
• Trapping the flies is even cheaper if you
make the traps yourself, but may not be as
effective. Fruit flies are attracted to sugar and
protein, so make a bait by mixing fruit juice or
honey with a protein source like wheatgerm,
Marmite or Vegemite, and add water to make
the bait liquid enough to drown the flies. Place
bait in the traps described on p. 18 or 25. You
can also add some pyrethrum to kill the flies
on contact.
• Choose early fruiting varieties for your
garden, as the problem tends to get worse as
the season progresses.
• Remove from your garden and nearby
unwanted fruit trees or other host plants that
attract fruit fly.
• Increase habitat for predators of fruit fly such
as ants, ground beetles, spiders and birds
by having a bigger variety of plants in your
garden.
• Use poultry to scratch under your fruit trees
and eat the pupae.
Monitoring
Check fruit on the tree for
‘stings’, and check fruit that
has fallen off the tree to see
whether it has stings or larvae
inside the fruit. Eggs are white
and banana shaped, and
larvae are white with paired
black mouth hooks.
Prevention
• Keep fruit trees at a
manageable size by
pruning or planting dwarf
trees so it’s easier to
control the fruit fly.
• Use exclusion methods
(eg, nets, bags, or sleeves
for the fruit) to stop the
24
Queensland fruit fly
© Mt Alexander Fruit Gardens 2014
A
Treatment
Keeping fruit fly under control really
depends on destroying any larvae you
find, because the population can very
quickly build up (and spread to your
neighbours). It’s not enough to just
gather any fallen fruit; you must also be
sure to destroy any larvae that might
be in the fruit by one of the following
methods:
• put fruit in a pot and bring to the
boil;
• put fruit in a sealed, black plastic
bag in the sun for a few days;
• freeze fruit;
• immerse in water for at least a
week, but be very sure to make
sure it stays underwater.
• bury in a pit at a depth of 60-90
cm—this is pretty deep, so is not
very practical unless you have some
earth moving equipment to dig a
serious hole!
After treatment with one of the above
methods to make sure the larvae are
killed, fruit can safely be fed to chickens
or other animals, or put in the compost.
B
Fruit fly trap
Mediterranean fruit fly
25
© Mt Alexander Fruit Gardens 2014
Fruit tree borer
weaken or kill the limb. When large enough,
larvae pupate, and adults emerge in autumn/fall
and are usually active over the winter months.
Pest of: all fruit trees
Monitoring
F
ruit tree borer can kill whole trees, or
sometimes just limbs, and are often found to be
the culprit behind a mysterious dead limb.
Fruit tree borer’s proper name is Maroga
melanostigma, and it’s actually the larvae of an
indistinct native (to Australia) silvery grey/light
brown moth that’s quite small, about 60 mm from
wing tip to wing tip.
They affect all types of stone fruit, including
plums, apricots, cherries, peaches and nectarines,
but are less often found in apples or pears.
Life cycle
Moths lay their eggs on the bark of a tree, where
they hatch, and the larvae burrow into the wood,
creating a tunnel, then emerge at night to feed on
the surrounding bark.
Larvae can live for up to 2 years in the branch,
and their feeding can ringbark the branch and
Typical
borer hole
26
The tunnel entrance is covered by a mass of
visible frass (brown, sawdust-like stuff), chewed
bark and webbing, and is quite distinctive.
Check trees regularly, particularly if a limb is
dead or sick. Some trees respond by producing
gum which oozes from the damaged area (which
can at times be confused with gummosis caused
by disease or some other type of damage). To be
sure of your identification, scrape the frass away
until you find the hole—it’s usually clearly visible,
and about 3-5 mm wide at the entrance.
Prevention and treatment
There is no preventive treatment for borer,
but as soon as you discover it through regular
monitoring, and find the hole, it’s quite easy to kill
the larva by poking a piece of wire into the hole
and wiggling it. If you’ve been successful, the wire
will come out wet!
Frass around
borer 2014
hole
© Mt Alexander
Fruit Gardens
Garden weevil
Pest of: cherries, apricots, peaches,
nectarines, apples, pears
G
arden weevils are just one of many different
types of weevils that are pests of fruit trees.
They look like a tiny, slow-moving elephant
beetle, with a large round body. They have similar
habits to earwigs, and are similarly destructive
to fruit, particularly small, soft-skinned fruit like
cherries, apricots, and nectarines. They can also
be pests in apples, causing damage to both fruit
and leaves.
They are nocturnal and hide during the day
inside damaged fruit, under loose bark or debris
or under leaves. Fully grown weevils are a
greyish-brown colour, and only about 7 mm long.
Life cycle
Garden weevils have a complete life cycle, which
means they go through each insect development
27
stage of adults laying eggs, which hatch into
larvae, which pupate.
Towards the end of summer, eggs are laid on
the soil under the protection of leaves or mulch,
and hatch in 10-14 days. Larvae burrow into the
soil to feed on plant roots, and overwinter there,
slowly developing. As the soil warms in spring
development speeds up, and they pupate in early
spring (September in the southern hemisphere)
which takes about 3-4 weeks, and then adults
emerge from the soil in mid-to-late October, with
populations building to a peak in early summer,
when they do most damage.
They usually only go through one generation
a year, but occasionally two. Many adults survive
throughout summer, and a few hardy souls make
it through winter as well.
Monitoring
The main damage the Garden weevil does
is directly to the fruit, so monitor apricots,
nectarines, and cherries, particularly the fruit
closest to the ground, and towards the centre of
the tree, where damage is more likely to occur.
© Mt Alexander Fruit Gardens 2014
Garden weevils can seriously
damage stone fruit
Typical damage includes serrated edges of
lower leaves, skeletonisation towards centre of
leaves, chew marks on leaf stalks, and chewing of
skin and underlying flesh of fruit.
Damage to fruit might be confused with that
of Light brown apple moth larva, but is usually on
exposed parts of fruit (rather than hidden parts),
and there’s no webbing.
If you’re planning to put a barrier around the
trunk of the tree (see below), it’s much better
to do it before you see any damage to the fruit,
preferably before mid-spring when the adults are
likely to emerge.
Prevention and treatment
• Predators include birds, lizards, and
nematodes, so provide diverse habitat!
• Poultry, such as chickens, turkeys, and
guinea fowl, love to eat both garden weevils
and earwigs. A population of 50 birds to
the hectare (or even one or two in a small
garden) can be enough to really help to keep
them under control. If you’re planning to use
chickens, it can be very useful to confine them
for a period around each tree to make sure
they have a really good peck. This is also a
reason to not confine them all the time around
your fruit trees, or they can damage the roots.
• The easiest way to prevent these walking
insects is with a sticky barrier around
28
the trunk of your tree. This can either be
horticultural glue, or some kind of sticky tape.
We use double-sided sticky tape. A hint: if
you’re relying on a band around your tree
trunk to prevent crawling insects getting into
the tree, keep the grass cut around the tree
to make sure you’re not providing easy access
with an insect ‘ladder’.
Similar pests
Curculio beetle (also called Apple weevil or Plum
curculio), Fruit-tree root weevil, Fuller’s rose
weevil, and Whitefringed weevil.
It doesn’t particularly matter which type of
weevil you have—the method of keeping them
out of your trees is essentially the same. If weevil
larvae are a problem in the soil because they
are eating the roots of your tree, the solution
is the same as for Codling moth or any of the
other pests which spend part of their life cycle in
the soil, ie, keeping chickens or other foraging
animals under your fruit trees for a period so
they can peck around and remove these delicious
grubs!
The two main solutions are banding, and—you
guessed it—biodiversity. The populations of these
weevils will naturally be kept under control by
having a diversity of other life in your garden and
your soil.
© Mt Alexander Fruit Gardens 2014
Grasshoppers
Pests of: apples, young nonbearing
trees
G
rasshoppers are usually wingless as adults.
They are similar to both crickets and locusts
in that they are chewing insects, with very strong
mouth parts that allow them do a lot of damage
to your fruit trees!
As with so many of the insects in our garden,
this group also includes some beneficial predator
species which kill and eat more damaging insects.
It’s never as simple as solving a problem by
getting rid of one type of insect; it is always much
more effective to aim to have a very diverse,
balanced ecosystem in your garden, then get out
of the way and let the insects fight it out amongst
themselves!
Other predators include tachnid flies, parasitic
wasps, and robber flies. Provide as many
different types of habitat in your garden
as possible, including a water source like a
pond or dam to attract the larger predators
like frogs and lizards (though you don’t
necessarily want to attract snakes!).
• Large trees rarely suffer much damage from
grasshoppers. Small trees can be protected
by completely covering the tree with a
fine netting or mesh. This should only be
necessary for the first year or two of a tree’s
life (and only in response to any damage you
notice when you monitor the trees).
Similar pests
Crickets
Grasshoppers can completely
defoliate young trees
Life cycle
Grasshoppers overwinter as eggs, hatching
into the nymph stage in late spring or early
summer (November or December in the southern
hemisphere). They swarm in long grass around
the edges of gardens or orchards, and when
the grass dries out, will invade the plants in the
garden, including fruit trees.
Monitoring
Look for holes in leaves, particularly in young,
nonbearing fruit trees. Damage can be so severe
that trees become completely defoliated, though
they may recover if grasshoppers are predated or
move on.
They can also chew holes in apples and other
fruit, removing both skin and a thin layer of flesh
around the fruit.
Prevention and treatment
• They are slow moving in the morning, so it’s
not too hard to catch them by hand (and feed
them to the chickens!)
• As for earwigs and garden weevils, poultry are
an excellent control mechanism!
• Grasshoppers have a surprising number of
predators, including birds, lizards, snakes,
assassin bugs, frogs, ants, fungi, and worms.
A
29
Grasshopper damage in peaches
© Mt Alexander Fruit Gardens 2014
Heliothis
(also called Budworm, or Looper)
Pest of: cherries, apricots, peaches,
nectarines, plums, apples, pears
T
here are several species of heliothis that might
affect your fruit trees, the most common being
Corn earworm, Native budworm, Apple looper or
Twig looper (these last two are usually only found
on apples and pears). Luckily, they are rarely a
serious problem.
Moths are various shades of brown, and
larvae are quite large grubs ranging in colour
from greyish white, to green to brown. Larvae of
loopers move with a characteristic looping motion.
Life cycle
These pests go through a complete life cycle. The
adult moth lays its eggs on leaves, the larvae
hatch and feed on both leaves and fruit, often
leaving characteristic round clean holes in the
fruit. Fully grown larvae usually drop to the soil
to pupate, before the next generation of adults
hatch.
Monitoring
The first sign of damage is usually holes in the
leaves, you may also notice small, neat, round
holes in the fruit, particularly apples and pears.
Prevention and treatment
In most cases you can just pick these off by
hand when you notice them. Normal hygiene
practices such as letting chickens have a peck
around in the soil under the trees in autumn or
spring will normally be enough to keep these
pests under control. As you’ll see in the section
on predator insects (p. 40), larvae of these pests
(which are more commonly known as caterpillars)
are predated by many beneficial insects in your
garden.
A
Native budworm larva caterpillar
B
Twig looper larva caterpillar
30
C
© Mt
Alexander
Fruitlarva
Gardens
2014
Corn
earworm
caterpillar
A
Mealybug
Pest of: plums, occasionally other
pome and stone fruit
M
ealybugs are an occasional problem, but
usually only in trees or orchards where
insecticides have been used. They belong to the
same group of insects as scales.
Life cycle
Mealybugs have an incomplete life cycle. The first
stage nymphs (instars) stay with their mothers for
a couple of weeks, then branch out by themselves
to colonise a new part of the tree.
Adult mealybugs are white with distinctive
ridges on their bodies, and can be up to 6 mm
long. One of the most common pest mealybug
species in Australia is called the Long-tailed
mealybug, which has a distinctive long tail. The
nymphs may be pink rather than white.
Monitoring
Mealybugs cause damage in two ways: They pierce
fruit and suck out the juice, and they produce
honeydew which attracts black sooty mould, which
makes a horrible black mess in the tree, and is
often the first sign you’ll notice.
Because they produce honeydew, they may be
‘farmed’ by ants in the same way as aphids.
Prevention and treatment
Like aphids, mealybugs have many natural
predators, including their very own ladybird called
a Mealybug ladybird, whose larvae look very
similar to the mealybug (see photo below). In a
diverse garden where no insecticides are used, it’s
extremely unlikely to be a bad enough problem to
need treatment.
If you notice ants that are looking after the
mealybug population, you can exclude them from
the tree with barrier tape, thus exposing the
mealybugs to predation.
B
Mealybug infestation
Mealybug ladybird
larva
31
© Mt Alexander Fruit Gardens 2014
A
Pear leaf blister mite
Pest of: pears
L
ike most mites, pear leaf blister mite mainly
damages leaves, but can also damage young
fruit. The adult mites are minute (you need a
magnifying glass to see them) and they live inside
the blisters that form on leaves in response to
their presence, eating the leaves from the inside,
so they're well protected. The body is white, and
has a few long hairs on them, and the eggs are
also tiny, white, and spherical.
Life cycle
They have an incomplete life cycle, which means
they lay eggs and the immature stage is a nymph,
that looks very like the adult. They don't have a
larvae/pupae stage.
Prevalence of this pest tends to go in cycles.
They overwinter as mature females hidden in the
leaf and fruit buds on the tree. In spring when
the buds begin to swell, the females lay eggs
in emerging leaves, then both the females and
the emerging young cause the blisters by eating
the developing leaves. Several generations can
develop inside the blisters in a single season,
because a generation only needs 10-12 days to
develop.
Pear leaf blister mite damage makes the tree
look a bit ugly, but in most cases does little harm.
The mites suck the juice from leaf cells and will
reduce the photosynthetic ability of the leaves.
In really severe infestations they may cause
partial defoliation, which can reduce the amount
of energy the tree can generate to put into fruit
growth, and into growth of next year’s buds.
Monitoring
You’ll usually only know you have this pest when
you see the blisters on the leaves, which are
globular, and a paler green than the rest of the
leaf at first, becoming dark brown to black as the
season goes on. Because the majority of the life
cycle happens inside the blister, you’re unlikely
to see any insect activity. You may also see
reddish blisters on the actual fruit, but this is less
common.
They tend to not do too much damage, as
they'll only move to a new leaf if the current leaf
gets too crowded, so as always the first rule of
pest control is to not panic! It looks horrible, but it
actually doesn't do much harm, and doesn't really
affect the tree's ability to produce fruit.
Prevention and treatment
This will stop the mites going through their
life cycle and re-infecting the tree next year.
However, if a lot of leaves are infected there's
a possibility you can do more harm than good
if you remove too many leaves, because the
leaves will probably still be photosynthesising.
• The other time for control is when the mites
emerge from the leaf blisters after harvest
(in autumn) and migrate to the buds to
overwinter—they're relatively exposed in
the buds until spring. Spraying the tree with
winter oil (an organically allowed mineral oil)
in winter will smother these adults.
Similar pests
Bryobia mite, Apple rust mite, Peach silver mite,
European red mite, and Two-spotted mite. There
are also several predatory mite species that eat
pest mites.
Bryobia mite can cause mottling of leaves
(old leaves worse than young leaves) and heavy
infestations can affect fruit size and colour.
Apple rust mite and Peach silver mite both
overwinter under the scales of buds. Early signs
of damage are upward bending of sides of leaves.
Peach silver mite may also cause yellow spotting
of leaves, and a heavy infestation can make the
leaves of peach trees look quite silver, which can
be confused with the fungal disease peach silver
leaf.
European red mite are a pretty red, and eggs
overwinter on bark and hatch in early spring.
Heavily infested leaves show fine mottling on the
upper surface.
Two-spotted mite causes leaves to become
mottled or brown, and drop early. They also like
dusty surfaces, so try to prevent dust settling on
the leaves of your stone fruit trees.
B
There are two main things you can do for control:
• Remove infected leaves and make sure you
destroy them (putting them in the sun in a
black plastic bag for a few weeks should do
the trick, before they go in the compost).
32
© Mt Alexander Fruit Gardens 2014
Pear and cherry slug
Pest of: pear and cherry trees,
occasionally plums
P
eople tend to get alarmed when they find these
slimy critters on the leaves of their trees, but
the truth is, on mature trees, they generally don’t
do any significant damage. It’s more important
to control them on young trees, where a really
severe infestation can kill a tree.
The slugs you find on the leaves are actually
the larva of adult sawflies (a type of stingless
wasp with two sets of wings). The dark green
slugs are around 5–10 mm long and feed on the
green parts of leaves, leaving them skeletonised.
While they can make a tree look really sad and
bedraggled, they are one of the less harmful pests
because they don’t attack fruit, and are only really
a problem when in large numbers.
Though mature trees can easily carry a small
amount of damage with no loss of growth, in
small trees the loss of leaf function can affect the
tree’s ability to grow, so it’s well worth trying to
keep slug numbers under control on these trees.
33
Life cycle
There are generally two broods per season, the
first in early summer and the second in autumn/
fall, so it’s not uncommon to notice these two
distinct waves of pear and cherry slugs on your
trees.
The adult sawflies lay their eggs in tiny slits
they make in the leaves. The eggs hatch, the
larvae emerge and then start feeding on the
leaves. When fully grown, the larvae drop to the
ground where they pupate just below the surface.
The second brood for the season will remain
underground before emerging next spring as an
adult sawfly. The adult flies then return to the
leaves and lay their eggs in slits made in the
leaves, and the cycle is complete.
Prevention and treatment
• If you only have one or two trees, folding the
leaves and squashing the slugs is the most
effective, although probably least pleasant,
option! (You don’t need to pull the leaves
off the tree to do this, so there’s no loss of
photosynthesis to the tree.) You may also
notice they have a distinct smell.
• Letting chooks scratch around under the trees
in winter to eat the dormant pupae helps too.
© Mt Alexander Fruit Gardens 2014
• Dusting the leaves with a dry powder such
as wood ash will effectively kill the slugs, but
just be sure to stand upwind when you do it,
to make sure you don’t breath in any dust.
Wearing a simple dust mask is also a good
idea when treating this pest. You will probably
need to repeat this treatment several times.
Mornings are best, while the leaves are often
still damp.
• If all else fails, organic pesticides containing
an active ingredient like pyrethrum or
spinosad are both effective, however USE
WITH EXTREME CAUTION—though allowed in
organic systems, these insecticides can kill a
wide range of insects, including beneficials,
and it’s easy to do more harm than good if
you use them incorrectly.
34
© Mt Alexander Fruit Gardens 2014
Rutherglen and
harlequin bugs
Pest of: all fruit trees
R
utherglen bugs and Harlequin bugs—also
sometimes called stink bugs—are similar pests,
in that both are sap suckers and will occasionally
suck the juice from fruit, causing pitting and
gummy ooze. The good news is they are mainly
attracted to fruit on sick trees, so keeping your
fruit trees healthy is an excellent defence against
them.
Life cycle
Being bugs, these insects go through simple
metamorphosis, from egg to nymph to adult, with
no larval stage.
Both nymphs and adults are usually active
in early summer (December and January in the
southern hemisphere), then adults lay eggs,
which survive over winter to hatch next summer.
Some adults may also survive the winter.
such a tree is easily digestible for them. Your
main anti-bug strategy should be continuous soil
improvement.
SOme bugs can be prevented from getting in
your tree with a barrier (see instructions on p.
23). They are also relatively easy to dislodge by
hand or by spraying with a hose, but are likely to
come back unless a barrier is in place.
If bugs remain a consistent problem, a winter
oil spray will help to smother their eggs and
prevent an outbreak the following summer.
As with all pests and diseases, biodiversity in
the garden is one of the best lines of defence,
as there are various predators such as birds and
wasps which will eat the nymphs.
Similar pests
Plague soldier beetle looks quite similar but
has a longer body, black with an orange ‘collar’.
The adults can do minor damage to apples and
cherries, but their larvae are predators of many
insects.
Monitoring
Rutherglen bugs are about 6 mm long, and are a
dull browny-grey colour, with large distinct wings.
Harlequin bugs, on the other hand, usually
have some sort of vivid black and red pattern
on their backs (the ones in the photo are the
common type on our farm) and are slightly larger.
They are often found mating, joined end to end.
If the bugs are going to be a pest on your fruit
trees, they will be very obvious, crawling all over
the tree and the fruit. If they are attacking the
fruit, it will look shrivelled, and may have small
depressed pits, or be oozing gum.
Prevention and treatment
Bugs are particularly attracted to trees that have
incomplete proteins, or amino acids, in their
sap. Unfortunately this is the situation that can
easily be created if you feed your tree artificial
fertilisers, particularly high-nitrogen fertilisers,
because they provide soluble nutrients directly
to the tree and can easily result in incomplete
proteins in the sap.
A healthy tree in healthy soil with an active soil
food web making sure the tree gets the nutrients
it needs at the right time will always make
complete proteins, and attract far less pests and
diseases.
Bugs can be a great indicator pest, telling
you that your tree—for some reason—is getting
incomplete nutrition, or is under stress. This
might be due to waterlogging, drought, root
disease, insufficient microbial activity in the soil,
or poor soil that has too little organic matter.
Trees grown under these conditions are much
more likely to attract bugs, because the sap in
35
© Mt Alexander Fruit Gardens 2014
San jose scale
Pest of: all fruit trees
Life cycle
Immature nymphs overwinter on branches and
the trunk of fruit trees, then in spring they
develop into males (with wings) and females (no
wings).
Female adults are covered with a grey circular
scale—if you lift it up you can see the yellow
bodied adult underneath. Adults lay eggs under
the scale which hatch and emerge from the scale
as crawlers. The crawlers then move to new
growth or fruit, and start a new cycle.
They can go through four generations per
season, and in warm areas it’s possible that all
stages of the life cycle are present all year.
Monitoring
San jose scale damages the tree by feeding on
the bark and fruit. You’ll be able to see a heavy
infestation as a grey, scaly layer which you can
rub off the bark with your hand. If the scale are
still alive when you rub them off, you’ll end up
with a brown stain on your hand.
The first symptom you might see is a blob of
gum at the site of infestation. During the season
you may see crawlers (usually a pale grey colour)
moving to a new site on the tree.
Infected fruit is seen as round spots, which are
individual scales, each surrounded by a red ring.
Prevention and treatment
• Remove small infestations manually by
rubbing them off by hand.
• Prune out severely infected branches and burn
them.
• If you have an infection in your fruit trees,
check other potential host trees nearby for
infection—neglected fruit trees, suckers,
seedlings, tree lucerne (tagasaste) and willow
can all be hosts. Remove any infected wood
you find on any hosts.
• Spray the tree with dormant (mineral) oil in
winter to smother overwintering nymphs.
Similar pests
White peach scale is most common on peaches
and nectarines, usually only in warmer climates.
Damage, monitoring, and control are very similar
to San jose scale.
It seems to be favoured by high humidity, so
prune your trees and plan your garden to allow for
rapid drying of trees after rainfall.
36
Scale infestation
© Mt Alexander Fruit Gardens 2014
Thrips
Pest of: apricots, peaches,
nectarines, apples, plums
Plague thrips and Western flower thrips are the
two most common types of thrip that can cause
problems in fruit trees.
Both types are tiny—the largest are less than 2
mm long. They are elongate winged insects, and
the wings have a fringe of hair. Plague thrips are
so-called because they can be present in plague
proportions in spring (mid-to-late September in
the southern hemisphere).
Life cycle
A
dults move from their overwintering hosts
under the trees onto the fruit trees and lay
eggs in the buds as these are swelling in late
winter/early spring. The larvae then eat the tiny
developing fruit within the flower. The pupal stage
happens in the soil under the trees, then adults
emerge from the soil and feed on mature fruit
later in the season.
At 300C the life cycle of Western flower thrips
takes around 15 days and as the temperature
decreases it takes longer—up to 45 days at 150C.
In warmer areas, all stages of Western flower
thrips are present throughout the year.
Plague thrips are only a problem up until shuck
fall (flower drop), while Western flower thrips
can also cause damage to fruit in the pre-harvest
period.
Perfect conditions for Plague thrips are
provided by the sequence of wet autumn, mild
winter then a dry spring, with lots of weeds
flowering while your fruit trees are flowering.
Monitoring
T
he main time that damage occurs is inside the
flower, as the fruit is forming. Larvae feed on
the developing fruit surface, which causes tissue
scarring, russeting, and brown marks on the
fruit. They can also make the flowers wither, turn
brown, and die. This type of damage is usually
caused by Plague thrips. Plague thrips are known
to affect all apple varieties, but Granny Smith
seem particularly vulnerable.
Western flower thrips are more likely to cause
damage during summer and pre-harvest on
ripening fruit, caused by adults and larvae feeding
in the surface of the fruit. It shows up as a silvery
mark on the skin, and will often show up more on
the shady side of the fruit, or where two pieces of
fruit have been touching. White patches around
the stem end of the fruit are also likely caused
by Western flower thrips. The damage is often
patterned, particularly on apples, and is known as
‘pansy spot’.
We have had very little Western flower thrip
damage, but during the drought we noticed it
seemed to be worse because the alternative hosts
had died off because of lack of water, and the
thrip were attracted to the irrigated trees.
Western flower thrips will damage both pome
fruit (apples) and stone fruit (peaches and
nectarines), but seem to particularly favour bright
red nectarines!
Western flower thrip
37
© Mt Alexander Fruit Gardens 2014
Prevention and treatment
I
f thrips are a problem, refrain from mowing
the plants under your trees while the trees are
flowering, because this may displace the thrips
from other host plants (especially broad leaf
weeds like clover) into your flowers.
Both species of thrips are attracted to the type
of flowering plants that we encourage you to plant
under your fruit trees, and they especially love
white clover and lucerne (with white flowers) and
38
anything with yellow flowers. The good news is
that their predators are attracted to the same
flowers!
As a last resort you can use spinosad, an
organically allowed insecticide, but there’s a
very good chance you will also kill some of
the beneficial insects that would otherwise be
controlling the thrips for you, so it’s easy to do
more harm than good by going down this road!
Thrip damage on a nectarine
© Mt Alexander Fruit Gardens 2014
Predator insects
W
e’ve been telling you throughout this book
that one of your best defences against pests
is the predators that eat them, and it’s really
true! If this is a new idea for you, take some
time to watch the insect life in your garden, and
particularly in your fruit trees, and count how
many different types of insect you can see. Look
closely—there are actually thousands of different
insects around, many of which look similar but
may play a different role in the environment. Do
this regularly, at different times of the day, and
you’ll start to get a sense of the variety of insects
in the environment.
Some insects, such as earwigs and apple
dimpling bug, are pests in some fruit trees but
beneficial predators in others, and some species
of mites are pests while others are predators.
While the purpose of this book is to help you
identify the known and common pests that may
damage your fruit, and show you how to prevent
the damage, we hope you also come to see that
insects are not ‘good’ or ‘bad’. Just because we
see an insect on our fruit trees doesn’t mean it’s
a problem. In fact, we may never know what it is
or understand how it interacts with plants or other
insects. As long as we’ve taken steps to protect
our fruit, it doesn’t really matter what they are!
Birds also fit into the category of both pest
and predator, though usually a single species will
either eat fruit or insects. Lizards, arthropods,
small mammals and all sorts of other creatures
are part of the web of life in your garden that
helps to keep the pests under control.
Since we started our journey to organic
production more than 10 years ago, we’ve noticed
many ‘problem’ pests have disappeared. When we
stopped using insecticides in our orchards, insects
like woolly aphid, green peach aphid, thrips, mites
and pest bugs that were previously a problem
Wasps parasitising heliothis larvae
39
have either completely or mostly disappeared
from our orchards. We may get the occasional
piece of fruit showing damage, but rarely on an
economic scale any more.
Our experience mirrors that of other
organic growers, and even some advisors to
the orchardists who rely on chemicals are
starting to catch on, with commercial orchard
advice increasingly talking about ‘integrated
pest management’, using softer chemicals and
biological controls, and generally becoming more
aware of the importance of predator insects
in controlling pest populations. It’s a move we
wholeheartedly support, though there’s still a long
way to go until we achieve a complete return to
organic production!
The gallery on the following page shows just
a few of the beneficial insects you might meet in
your garden—we hope you appreciate them!
Biological control and buying bugs
t’s possible to buy in many of these predator
insects, and we’re often asked if it’s worth
it. The answer in most cases is no, particularly
for home gardeners, who have the flexibility to
introduce biodiversity into their gardens naturally,
and are aiming to keep costs to a minimum.
Buying in a population of predator insects or
microbes can be useful for commercial farms that
are in the early stages of transforming back to a
natural organic system but have not yet achieved
balance in their ecosystem. They are also
increasingly used by producers who want to take
advantage of the benefits the beneficials provide
but want to keep using chemicals in their system
which don’t allow the natural predator populations
to build up. Unfortunately, this commits them to
having to keep buying in the predators.
I
Apple dimpling bug damage
© Mt Alexander Fruit Gardens 2014
Ladybirds
A
Mealybug ladybirds
B
Mite-eating ladybugs
C
Plague soldier beetles
D
An important predator of aphids and mites, it’s extremely
common to see these ladybirds in a tree just after you spot the
first aphid colony! Both larvae and adults eat mites.
This unassuming looking ladybird is a major predator of
mealybugs, scales and occasionally aphids. Its larvae are covered
with white mealy flakes, and look just like the mealybugs the
adults eat (except they lack a tail!)
Though not as pretty as some of its cousins, this ladybird
powers through a lot of mites, particularly Two-spotted mite and
European red mite. Both the adults and larvae will gobble up
thousands of mites.
Plague soldier beetles are one of those insects that perform both
useful and annoying functions in our garden. The larvae are
predators of a range of insects, but the adults will sometimes
have a munch on small apples or cherries.
Green lacewings
Green lacewings are predators of aphids and scales. The larvae
have sickle-shaped jaws which they thrust into their victims and
suck out the contents, and then add insult to injury by carrying
the shells of their victims on their backs, which gives them
camouflage. To feed on scales they use their strong jaws to prise
the scales off their host plant.
E
Hover flies
F
Hover flies mimic bees and wasps with black and yellow bands
across the abdomen. The larvae are predators of aphids and
less commonly mites, and the adults (which have a distinctive
hovering motion) feed on pollen and nectar, making them useful
pollinators. You may see the brown tear-shaped pupae under
leaves, or in the leaves and litter on the ground.
Braconid wasps
Braconid wasps parasitise larvae of various moths, including
Budworms and Light brown apple moth and directly into aphids.
The females lay their eggs directly into the larvae, where they
develop by eating the larva from the inside out!
G
Aphelinus mali
The tiny black aphelinus mali wasp is a parasitoid of woolly
aphid, laying its eggs directly into the aphids, which then
lose their woolly white covering and go black, then die. Dead
aphids will have a clear hole in their body showing where there
parasitoid has emerged!
Spiders
Spiders play a very important part in the ecosystem of your
garden, catching many insects. In our orchard we’ve seen some
mighty battles between spiders and earwigs, grasshoppers, flies
and aphids, with the spider often catching a meal many times
as large as itself. Though they sometimes freak the (human)
workers out, we consider spiders to be an asset in our fruit trees.
Predatory shield bugs
This bug is a predator of caterpillars such as budworms. The
adults are greyish brown with distinctive pointed shoulders, as if
they were wearing shoulder pads—so ’80s! The eggs are black,
and the nymphs are dark red and brown, and are laid together in
big patches—you can see nymphs hatching from eggs on this leaf
in our plum orchard.
40
© Mt Alexander Fruit Gardens 2014
Make your own organic pesticides
M
ost pest issues resolve by themselves over
time in a balanced organic garden, as you
increase the biodiversity in the garden. The
reason we give insecticides as the method of last
resort when it comes to methods for controlling
each pest is because if they’re used wrongly, they
can kill nontarget insects and do more harm than
good.
However, as growers of our own food, we also
want to make sure we get plenty of delicious
organic fruit in return for our labour, every
year. Having food security depends on it! So,
sometimes insecticides are needed, for example
to save young trees from infestations that would
kill them, or to help get plague populations under
control while the predator populations build up.
In these cases it can be cheaper (and often as
effective) to make your own sprays at home.
Lots of certified organic insecticides are now
available to buy off the shelf, and they do have
some advantages over home-made brews,
because
• they must comply with the law and with
organic standards;
• they may have additives that make them
‘stick’ and therefore work more effectively;
and
• they usually come with clear instructions and
safety information on the label; these are
extremely important—read them, and follow
them closely!
However, these products are expensive, and you
may have to buy much more than you need to do
a particular job.
The table on the following pages lists of some
of the organic insecticides you might find on the
shelves.
Green lacewing larva
41
© Mt Alexander Fruit Gardens 2014
NASAA*
requirements
Product
Origin, use and recommendations
Bacillus
thuringiensis
(Bt)—sold as
DiPel
Bt is a bacterium, used as a biological pesticide. The bacteria produces a
toxin that, when eaten, attacks the guts of caterpillars, moths (eg, Codling
moth), flies, wasps, bees, ants, sawflies, nematodes and beetles, causing
them to starve to death. Bt has a long association with GMO technology—
plants have been engineered to produce the same toxins as Bt, though
experience is showing that insects gradually become resistant to the toxin,
and farmers revert to using insecticides. Bt is used in GMO versions of
corn, soybean, and cotton. Many studies have shown harmful effects of
GMO technology. Though non-GMO versions of Bt are allowed in organic
systems, the jury is out on how toxic DiPel actually is. We don’t use or
recommend any Bt products.
Must be non-GMO or
GMO derived
Boric acid
Used to kill ants, which will help to control aphids by stopping the ants
‘farming’ them. We don’t recommend killing ants; it’s much easier to keep
them out of your fruit trees by banding the trunks of the trees, and ants
perform a lot of useful ecoservices in your garden.
Not to be used in
direct contact with
food, soil, or plant
tissue.
Clay (eg,
bentonite or
kaolin)
Clay can be used dry for pear and cherry slugs or mixed into a slurry and
sprayed on for aphids, scale, or mites. If you’re spraying with clay, wash
your spray equipment promptly and thoroughly or you may never be
able to use it again. To use clay dry for pear and cherry slug, observe the
warning given on p. 46.
Derris dust
(including
derris elliptica,
Rotenone)
A broad-spectrum insecticide, made from the seeds and stems of various
plants, including the jicama vine plant. Like pyrethrum, it’s broad
spectrum, ie, will kill most things it comes into contact with, including
beneficial insects. Derris dust or Rotenone are commonly sold to kill a
wide range of pests, including beetles and caterpillars. It acts as a contact
spray and rapidly biodegrades under warm conditions, so harmful residues
are minimal. However, it’s classified by the World Health Organization as
moderately hazardous, and is known to be mildly toxic to humans and
other mammals. We don’t use or recommend the use of derris dust.
Diatomaceous
earth (DE)
Naturally occurring, soft, silica-based rock product that is sold as a white
powder. It’s actually made of the bodies of diatoms, a type of hard-shelled
algae. It works as an insecticide (eg, for pear and cherry slug, mites,
ants, arthropods) by dehydrating the insect. Only food-grade DE has small
enough particle size for this purpose. Observe the warnings given for using
dry products on p. 46.
Plant extracts,
plant and animal
oils (sold under
various brand
names)
There are various combinations of plant products and oils, formulated
for various situations and insects. Read the label carefully, use only for
the insects for the which the product is intended, follow instructions
completely, and only use as a last resort. Dispose of residue carefully
(some of these products may be toxic to aquatic animals if they get into
waterways).
Insecticidal soap,
potassium soap
Soaps made from potassium fatty acids can be used to control pests like
aphids, mealybugs, spider mites, thrips, caterpillars, and leafhoppers,
though they’re not terribly effective; in trials they’ve been found to kill
40%–50% of populations. They work as contact sprays, ie, the spray
solution has to coat the pest. Probably the best effect is gained from using
them in combination with a mineral oil or plant oil. They have low toxicity
on beneficial insects like ladybirds and bees, and very low toxicity for
people, though they can be mildly irritating to skin or eyes. Insecticidal
soap can be phytotoxic to trees, which means it can burn or mark the
leaves or fruit of your trees. Don’t spray trees in flower. If in doubt about
how it may affect your tree, spray a small part of the tree first and wait for
48 hours. Don’t use over 320C, or on sunny days. They are best applied
in the early morning. Don’t mix with Derris dust, lime sulphur, copper
sulphate, or Bordeaux. Mix the soap spray with soft or demineralised
water.
Mineral oils (may
also be called
white oil, winter
oil, summer oil,
dormant oil,
horticultural oil)
Mineral oils are lightweight petroleum-based products that control pests
by suffocation of one of its life stages—adult, nymph or egg. They can be
used to control aphids, mites, and scale but, as for insecticidal soaps, they
are not terribly effective and can be phytotoxic. They have little effect on
a lot of beneficial insects like ladybirds, bees, and parasitic wasps. They
should not be used at temperatures over 300C. At times we’ve used a
mineral oil in winter to help smother aphid eggs, but as our biodiversity
has improved, the number of natural predators for aphids has increased,
and we now never need to use a mineral oil. Vegetable oils can easily be
substituted for mineral oils.
42
Not near aquatic
systems or on edible
plant portions.
Unfortified, natural
extraction.
Includes animal
fats, alcohols,
marigolds, sesame,
garlic, chilli. Ok
provided no potential
contamination of end
product. Specified
source, free of
prohibited inputs,
natural extracts only
Light petroleum
derivatives allowed
as suffocating oils
on foliage, dormant
summer oils.
Direct application
to harvested crop
prohibited.
© Mt Alexander Fruit Gardens 2014
NASAA*
requirements
Product
Origin, use and recommendations
Spinosad (sold
as Naturalure,
Eco-naturalure,
Entrust)
This is a very useful bait to use against Queenlsand fruit fly and
There are several
Mediterranean fruit fly. The active ingredient is spinosad, which is produced certified organic
from a bacterium and will kill many types of insects including thrips,
products available
caterpillars, and moths. In formulation, eg, as Naturalure, it includes
protein-based fruit fly attractants. It’s applied as a blob or a band to the
trunks of trees, or the grass underneath them, starting from 6 weeks
before harvest until all the fruit is off the trees. Re-apply every 7 days.
Around the world spinosad is used as an insecticide, and also to kill fleas
on animals, and head lice on people!
Neem oil and
extracts
Neem oil is produced from seeds and fruits of the Neem or Indian lilac
tree. It contains a range of active ingredients including azadirachtin,
and is an active insecticide against more than 200 pest insects including
mealy bug, aphids, thrips, mites, beetles, moth larvae, flies, leaf miners,
caterpillars, locusts, and pathogenic nematodes. Rather than killing
the insects directly, it acts as an antifeedant, repellent, and egg-laying
deterrent. It needs to be reapplied every 10 days. It is practically nontoxic
to people and other mammals, and has little effect on many beneficial
insects such as bees, ladybirds, or wasps. Neem oil is also used to
control a range of horticultural diseases, and has a wide range of uses in
traditional Ayurvedic medicine (being considered antihelmintic, antifungal,
antidiabetic, antibacterial, antiviral, contraceptive, and sedative) and
cosmetics.
As part of integrated,
ecological pest
management,
natural extraction, no
prohibited inputs.
Pheromones, in
traps or twists
Mainly used for Codling moth (but available for other moths as well),
these pheromone ties have become the industry standard because they
work so well! Tags or twists are infused with female pheromone (called
codlemone—cute, huh?) which thoroughly confuses the poor males so
they can’t find a female to mate with. Moths have a very short ‘window’
when they can mate—after 3 days an adult female will have only half the
number of viable eggs. We rely on pheromones to control Codling moth,
and recommend them for any growers that have the number of trees, size
of garden, or resources to justify the cost. Note: pheromones should be
distributed at the recommended rate over at least 1 ha—using them on a
smaller area can be counterproductive.
Not used directly on
crops, non GMO or
GMO derived
Pyrethrum
A natural insecticide made from the dried flower heads of two types
of perennial daisy—the Dalmatian chrysanthemum, and the Persian
chrysanthemum. Both are also called Pyrethrum daisy. The active
ingredient is called pyrethrin and comes from the seeds. It attacks the
nervous system of all insects, which makes it a broad spectrum—and
therefore potentially dangerous—insecticide, particularly to bees and
wasps. It has very low toxicity to mammals and birds, and breaks down
quite quickly in the environment. If used at all it should be with extreme
caution, and only spot-sprayed on infestations of pest insects, after close
examination to make sure damage to predator insects will be minimal, or
you might just be making the original problem worse. Chrysanthemum
plants can have useful pest-repellant properties as companion plants,
which is why it’s not uncommon to see them in vegetable gardens.
As part of integrated
pest management,
not storage. Not
synthetic origin,
piperonyl butoxide
(PbO) prohibited.
Sodium
bicarbonate
(bicarb, baking
soda)
Mainly used as a fungicide (as well as about 1,000 other household uses!),
bicarb soda can also be used in combination with water and soft soap
against scale insects. We’ve never tried it.
Quassia
Quassia is a small tree that produces in its wood the active ingredient
quassin, which is used as a contact insecticide and has been shown to be
effective against aphids, some beetles, and some caterpillars. Bark chips
from the tree Picrasma quassioides are also sold as quassia, but are not
registered for use in organic farming in Australia.
Extracted from
Quassia amara
* NASAA = National Association of Sustainable Agriculture Australia (one of the main organic
certification bodies in Australia)
Ant guarding black
aphids
43
© Mt Alexander Fruit Gardens 2014
Insecticide recipes
I
t makes sense to learn how to make your own
insecticides, as organic gardeners have done for
hundreds of years before us, when all gardening
was organic!
Many of the following recipes recommend
adding a bit of soft soap to help the sprays
stick. Don’t use commercial dishwashing soap,
but rather make your own solution by grating
some pure soap into hot water. Some of them
we’ve tried ourselves, some are tried and true
recipes from other people, some we’ve picked up
during our research. Let us know any particular
favourites you have and we may include them in
future editions of this book.
Bug juice
This remedy works well for plant-sucking bugs
like harlequin bugs, as well as other beetles,
caterpillars, or slugs by repelling the live bugs of
the same species. It also attracts their natural
predators, and possibly spreads disease within the
bug population.
Collect a handful of the problem bugs, and
put them in the blender with 2 cups of water or
milk, or mash them up with a mortar and pestle
dedicated to the job, if you feel a bit squeamish.
Let the brew sit for a few hours, dilute with water,
filter the mixture, add a bit of soft soap to help it
stick, and spray on your plants.
Flour and other dry stuff
Ash, flour, clay, lime, chalk, diatomaceous earth,
or rock dust can all be sprinkled on pear and
cherry slugs, and may also be useful on aphid
infestations.
Use a dust applicator or shaker, or stockings.
It can be easier to mix the powder with water
to make a very loose slurry, and apply with a
watering can over the affected area during the
hottest part of the day so the water evaporates
quickly.
Either way, this remedy is only effective for a
short time, and needs to be reapplied regularly.
They will also wash off in rain, and may need to
be re-used several times.
Caution: Use a face mask when using any
dry product, stand upwind, and don’t overuse
products like ash, lime or chalk, to prevent
affecting the soil chemistry.
Chilli
A strong chilli solution can kill or deter small
soft-bodied insects such as slugs, snails, and
caterpillars, especially if you use hot chillies.
Grind up the chillies and cover with boiling water.
Leave to cool, then strain, dilute to a light-brown
colour, and spray. You can also mix the chilli with
wormwood, garlic, or any of the other strongscented plants mentioned here.
44
Elder leaf spray
This concoction can be used for aphids and small
caterpillars.
Boil a couple of big handfuls of leaves and
twigs in a couple of litres of water for half an hour.
When it’s cold, strain it and use straight away,
though it will keep for ages if you bottle it hot.
Garlic
Garlic is known to effectively kill phytophthora
root rot in the laboratory. A strong garlic solution
will also kill larvae (eg, pear and cherry slug),
aphids, and any soft-bodied insect.
Make a solution by crushing 8 gm of peeled
garlic cloves in 50 ml of water, and mixing for at
least 5 minutes to extract as much of the active
ingredients as possible. Strain, and then dilute
with water. Use a very strong mixture if spraying
directly on larvae to kill them; a weaker solution
sprayed over a wider area will act as an insect
deterrent. Mixing in a little bit of soft soap will
help the mixture to stick better.
Garlic breaks down very quickly (within 2–3
days) so spray when the bugs are active, and you
may need to respray several times.
Melia
Melia (aka Queensland white cedar) is a native
Australian deciduous tree that has the same active
ingredient—azadirachtin—as that Indian wonder
tree, neem (see table above). Oil extracted from
melia seeds makes an effective spray against
aphids and a range of other insects like mites and
thrip.
Melias are commonly used as street trees, and
seeds can be collected in late winter when they
are dry and shrivelled. Seeds have a soft outer
skin and pulp. Ideally these should be removed,
but actually you can just chuck a load of whole
seeds in a bag and crush them with a hammer,
making sure you crush the kernel (which contains
the oil) as well. Steep the crushed seeds in water
for a few hours, and then strain and spray. You
can add a bit of soft soap to help it stick.
Oil—mineral or vegetable
Oils are very useful hygiene sprays, used in
winter to smother aphid or earwig eggs. If using
vegetable oil, use canola or linseed (though any
vegetable oil can be used).
The drawback is that you’ll also smother the
eggs or overwintering adults of any predator
species.
To make the spray, mix 500 ml of oil with 200
gm pure soap and boil the mixture until the soap
has dissolved. Dilute this mixture with water at
the ratio of 1:15 before spraying—once you’ve
mixed it with water it will separate quickly, so
only dilute as much as you mean to use at a time.
You can also add some citrus oil, garlic spray,
pyrethrum, or potassium soap to make this spray
more effective.
© Mt Alexander Fruit Gardens 2014
Caution: Do not spray on very hot days or you
may burn leaves (see table above). Don’t mix with
copper or sulphur sprays.
Nettle
The common nettle makes a great generalpurpose insect spray and plant tonic, and is often
used in biodynamic growing. It can be particularly
useful for controlling aphids and leaf miners,
and nettles can also be used as an activator in
compost heaps.
Soak the nettle leaves in water for a few days,
then strain the water and use it straight away (or
within a couple of days) undiluted. Spray as a
spot spray directly onto the pest insect.
Pepper
Pepper can work well for some beetles and
weevils, as well as caterpillars.
Grind peppercorns then cover with alcohol and
soak overnight. Filter and dilute with water at
1:10, then spray. This mixture can be added to an
oil spray (see above) to make it more effective.
This spray keeps well for months (keep in the
dark).
Quassia
This is a great spray to make because it’s effective
against aphids, caterpillars, leaf miners, and
sawfly (pear and cherry slug) but doesn’t hurt
ladybirds or bees! It’s made using quassia bark
chips, if you happen to know where there’s a
quassia tree, or you can buy the chips online (see
table above).
Put a handful of chips in a saucepan, cover
with water, and boil for 10 minutes. Strain when
it’s cool, and dilute at 1:10 with water before
spraying. Add a little soft soap to help the spray
stick.
A diversity of insects in
45
the garden is helpful
Once made, it can be stored for months in a
dark place. It can also be used to drench the soil
around your fruit trees where it will be soaked up
by the tree roots and then kill sucking bugs that
eat your trees.
Caution: Don’t spray on fruit—it’s really bitter!
Wormwood
If you’ve got wormwood growing in your garden,
harvest a bucketful of leaves, cover with boiling
water and leave to soak while cooling. Strain, and
use to kill soft-bodied insects or aphids.
Additional safety information
• Always wear appropriate safety gear when
mixing or using sprays, including gloves, skin
protection, and eye protection.
• Make sure any spray you use won’t come
into contact with any children and animals
either directly or by touching the trees you’ve
sprayed.
• Only spray pest populations in a very
targeted way; don’t blanket spray your trees
(except when using an oil spray as a winter
hygiene spray). If the insects are hanging out
underneath the leaves, spray there and not
the tops of the leaves.
• Label all sprays clearly, and store them in a
dark place out of reach of animals, children,
and people who don’t know what they’re for!
• Don’t spray in the heat or the wind. It’s your
responsibility to make sure you don’t do any
harm to any plants in your own (or somebody
else’s) garden, nontarget animals, people, or
the environment (including the microbes in
the soil!).
• Never spray open flowers—there’s too much
chance of hitting beneficial insects.
• And finally, if using a bought product, R.T.F.L.
(read the f’n label)!
Feather-horned bug
© Mt Alexander Fruit Gardens 2014
Insect pest control
Step #10: Don’t panic!
through the seasons
H
ere’s an overview of the simple jobs you can
do in the different seasons to keep pests at
bay.
Winter
• Spray winter oil if aphids or bugs were very
bad
• While pruning, monitor for borer, remove any
diseased or infested wood if you can do so
without losing too much healthy growth and
remove any remaining fruit from tree
• Remove and burn corrugated cardboard that
was placed around trunks of apple and pear
trees to trap Codling moth pupae
Spring
• Apply physical barrier (eg, double-sided sticky
tape) to cherry, apricot and nectarine trees to
prevent earwigs and weevils getting into trees
• Also band apple and pear trees to catch
female Codling moths as they flutter up the
trunk after hatching in late spring
• Plant to attract beneficial insects and for
companion planting (until summer)
• Monitor fruit and trees for pests and treat if
necessary
Band trunks in
spring to prevent
insects (eg,
earwigs, garden
weevils) crawling
up into trees
Summer
• Monitor fruit and trees for pests and treat if
necessary
• Pick fruit when ripe
• Remove damaged or diseased fruit and kill
larvae if Fruit fly or Codling moth (until end of
harvest)
• Bait and kill Fruit fly (until end of harvest)
• Hygiene: remove all fruit from trees and
ground after harvest
Autumn/Fall
• Band trees with corrugated cardboard to trap
larvae
• Chooks under trees to clean up
• Hygiene: remove all fruit from trees and
ground, and remove any remaining fruit
‘mummies’ from tree
46
Chooks are great at cleaning up
under and around trees
Pick fruit when it’s ripe!
© Mt Alexander Fruit Gardens 2014
Contact us
Keep in touch with us
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that we’re building a community of like-minded
fruit growers - something we wish we’d had when
we were learning how to grow fruit.
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share info, swap stories, and stay in touch with
our daily news from the farm.
Sign up to our Weekly Fruit Tips newsletter.
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w: www.mafg.com.au
e: [email protected]
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Visit our Facebook page.
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Copyright: All material in this publication is copyright Mt Alexander Fruit Gardens. It cannot be used,
copied, shared, or distributed without written permission. Unless otherwise indicated on p. 48, photos
are copyright Mt Alexander Fruit Gardens.
47
© Mt Alexander Fruit Gardens 2014
References and
Step #10: Don’t panic!
photo credits
References
Andersen, A. 2000. Science in Agriculture: Advanced Methods for Sustainable Farming. Austin: Acres
USA.
Dodds, K., K. O’Malley, S. Hetherington, and J. Kidston. 2014. Orchard Plant Protection Guide for
Deciduous Fruits in NSW 2014-15. Tumut: NSW Department of Primary Industries.
Malipatil, M., D. Williams, and L. Semeraro. 2009. Pests of Pome and Stone Fruit and their Predators
and Parasitoids: A Pocket Guide. Melbourne: Biosciences Research Division, Department of
Primary Industries.
Marshall, T. 2010. Bug: the Ultimate Gardener’s Guide to Organic Pest Control. Sydney: Harper Collins.
Washington State University, Tree Fruit Research and Extension Center. http://www.tfrec.wsu.edu/
tfrec.html.
West Virginia University, Davis College of Agriculture, Natural Resources, and Design, Kearneysville
Tree Fruit Research and Education Center. http://www.caf.wvu.edu/kearneysville
Photo credits
All photos by Mt Alexander Fruit Gardens, except
as follows:
Cover: James Niland. CC2. WC
How to Use this Book: Donald Hobern. Canberra.
CC2. WC
Contents: Dominik Stodulski, via WC
P. 3: Public domain, via WC
P. 4: dhobern. CC2. WC
P. 6: Alvesgaspar (Own work). GFDL. WC
P. 9: Goldfinger820. Public domain, via WC
P. 15 A: OPPG. Anne Mooney
B: OPPG
C: Eran Finkle from Israel. CC2. WC
P. 19 A: Joachim K. Löckener (Own work). GFDL.
WC
B: Richard Wilde (Self-photographed). Public
domain, via WC
P. 20 A: OPPG
B: Olaf Leillinger (Own work). GFDL. WC
P. 21: Holly Beaumont
P. 22 A: Sanja565658 (Own work). GFDL. WC
P. 24: OPPG. Andrew Jessup
P. 25 A: Downtowngal (Own work). CC3-SA. WC
B: USDA. Public domain via WC
P. 27: Tarquin at en.wikipedia. GFDL. WC
P. 29 A: Donald Hobern. Canberra. CC2. WC
P. 30 A: CSIRO. CC3. WC
B: Arthur Chapman, Australia. CC2. WC
C: Gyorgy Csoka. Hungary Forest Research
Institute. Bugwood.org. CC3-US. WC
P. 31 A: Zeynel Cebeci (Own work). CC3-SA. WC
B: Jeffrey W. Lotz; Florida Department
of Agriculture and Consumer Services;
Bugwood.org. CC3-US. WC
P. 32 A & B: Mark Carter
P. 33: Bj.schoenmakers (Own work). CC0. WC
P. 36: (F lamiot (Own work). GFDL. WC
P. 37: Frank Peairs. Colorado State University.
Bugwood.org. CC3. WC
P. 38: OPPG
P. 40 A: dhobern. CC2. WC
B: Whitney Cranshaw. Colorado State
University. Bugwood.org. CC3-US. WC
C & D: Gilles San Martin. CC2-SA. WC
E: Bruce Marlin Date created: 02/06/2005
Location: Winfield, IL. USA
F: Toby Hudson (Own work). CC3-SA. WC
G: Stsmith (Own work). GFDL. WC
P. 41: Ellmist at en.wikipedia. Public domain, via
WC
P. 43: viamoi. CC2. WC
Abbreviations:
CC2 = CC-BY-2.0. http://creativecommons.org/licenses/by/2.0
CC2-SA = CC2-SA. http://creativecommons.org/licenses/by-sa/2.0
CC2.5 = CC-BY-SA-2.5. http://creativecommons.org/licenses/by-sa/2.5
CC3-SA = CC-BY-SA-3.0. http://creativecommons.org/licenses/by-sa/3.0
CC3-US = CC-BY-3.0-us. http://creativecommons.org/licenses/by/3.0/us/deed.en
GFDL = GNU Free Documentation Licence. http://www.gnu.org/copyleft/fdl.htm
OPPG = Orchard Plant Protection Guide. NSW Department of Primary Industries
WC = Wikimedia Commons
48
© Mt Alexander Fruit Gardens 2014