TPM/IPM Weekly Report
for Arborists, Landscape Managers & Nursery Managers
Commercial Horticulture
In This Issue...
- Weather update
- MDA Pesticide container
recycling
- Lilac borer
- Lesser peachtree borer
- Periodical cicadas
- What’s up with ginkgo?
- Dwarf Alberta spruce
- Woodpecker feeding
- Monitoring soft scale
Beneficial of the Week
Weed of the Week
Plant of the Week
Phenology
Degree Days
Announcements
IPMnet
Integrated Pest
Management for
Commercial Horticulture
extension.umd.edu/ipm
If you work for a commercial
horticultural business in the
area, you can report insect,
disease, weed or cultural
plant problems found in the
landscape or nursery to
[email protected]
May 27, 2016
Coordinator Weekly IPM Report:
Stanton Gill, Extension Specialist, IPM for Nursery, Greenhouse and Managed
Landscapes, [email protected]. 301-596-9413 (office) or 410-868-9400 (cell)
Regular Contributors:
Pest and Beneficial Insect Information: Stanton Gill and Paula Shrewsbury
(Extension Specialists) and Nancy Harding, Faculty Research Assistant
Disease Information: Karen Rane (Plant Pathologist) and David Clement
(Extension Specialist)
Weed of the Week: Chuck Schuster (Extension Educator, Montgomery County)
Cultural Information: Ginny Rosenkranz (Extension Educator, Wicomico/
Worcester/Somerset Counties)
Fertility Management: Andrew Ristvey (Extension Specialist, Wye Research &
Education Center)
Design, Layout and Editing: Suzanne Klick (Technician, CMREC)
Too Much of a Good Thing
By: Stanton Gill
Rain is great, but the
frequency of rain, cloud
cover, and mist we have had
over the last month has been
excessive. We are seeing an
increase of slug and snail
activity on herbaceous annuals
and perennials planted in
the landscape. We are also
receiving a number of reports
of large aphid populations
on landscape woody and
herbaceous plant material,
This small bee is necataring on a coreopsis
especially hellebores. The
flower on one of the few recent sunny days
continuous rain is suppressing
predator and parasite activity with resulting aphid populations exploding.
Check crape myrtles and you may find large populations of the crape myrtle
aphid feeding on the newly emerging growth.
This weekend it is supposed to finally dry out (in the short run), but we will
see the foliar disease and root rot issues show up as we move into sunny,
warmer weather.
Maryland Department of Agriculture: Pesticide Container Recycling Program
MDA has posted its schedule of collection sites for the 2016 Pesticide Container Recycling Program. Triplerinsed (or equivalent) will be colleted on the scheduled days and times at the sites. See the brochure for details.
Lilac Borer
By: Stanton Gill
I have not captured any adult lilac borers in my baited pheromone
traps. I am not too surprised since the weather has been
unseasonably cool this spring. We should start to see adult males
flying in the next week or two. When lilac borer is flying and
mating, you may need to provide protection to susceptible lilac
plantings, especially large old plantings.
One thing you can do to reduce lilac borer damage is after
flowering occurs come in and renewal prune the plant, taking out
the older, thicker stems. Lilac borer tends to damage older stems.
The younger vigorous growth is usually not damaged. I have been
growing several lilac species for the last 16 years and have used
this renewal pruning methods approach with great success. I have
not had to treat for lilac borer.
Now is the time to check pheromone traps
for lilac borer
Lesser Peachtree Borer
By: Stanton Gill
A male lesser peachtree borer was found in a pheromone trap on May 24 in central Maryland. It is the first
report that we have received this season. Peachtree borer and lesser peachtree borer are caterpillars of clearwing
moths (Lepidoptera: Sesiidae). The lesser peachtree is active first in the season and the females tend to lay
eggs in wounds on smaller branches. Keeping a tree healthy and growing vigorously is the best way to prevent
damage from the lesser peachtree borer.
Lesser peachtree borer is another clearwing borer that is active this week
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Periodical Cicadas Have Arrived!
By: Paula Shrewsbury and Mike Raupp
For those of you who are or want to be “Cicada Maniacs”
your lives have just improved! For those of you who are
a little (or a lot) uncomfortable with cicada’s crawling
and flying around you might want to spend more time
indoors, especially if you live where cicadas have started
their emergence in parts of western MD in Garrett County,
eastern OH, south-west PA, north-west VA, the northern
half of WVA, and soon in Long Island, NY. Brood V
periodical cicada (Magicicada spp.) adults have started to
emerge! From a plant damage perspective, there should be
no worries. The only damage ever noted from periodical
cicadas is flagging to branch tips caused by the oviposition
of eggs into the branches. This is only a problem on young
trees with relatively few branches. The flagged branches
can be pruned out after the cicadas have emerged (around
late July).
For parts of Maryland, Virginia, West Virginia, Pennsylvania and Ohio, cicada romance will soon be in
the air!
Photo: M.J. Raupp, UMD
Periodical cicadas have a wondrous and unusual life cycle
for an insect. Periodical cicadas have either a 17 year
or a 13 year life cycle. They spend either 17 or 13 years
underground as nymphs feeding on sap from tree roots.
They then emerge in spring (usually May) as nymphs and
molt into adults on the 17th or 13th year. One of many
wonders of these insects is that broods of 13 and 17
year cicadas emerge on different years and in different
locations. A brood of cicadas emerge somewhere in the
eastern or central U.S. almost every year. There are 3
broods of 13 year cicadas and 12 broods of 17 year cicadas.
Many of you may remember the emergence of Brood X 17 Cicada nymphs will appear by the handful in areas
year periodical cicadas in 2004. Since then parts of MD
where Brood V is emerging
Photo: M.J. Raupp, UMD
have seen Brood II and Brood XIV. For a list of Broods
and when and where they emerge go to: http://www.
cicadamania.com/where.html.
To learn more about periodical cicadas (including Brood V) go to: http://www.cicadamania.com/cicadas/
category/broods/brood-v/
Periodical cicada’s will be featured on Mike Raupp’s “Bug of the Week” blog starting this Monday, and he
already featured them the week of April 25th, 2016 (go to: http://bugoftheweek.com/blog/2016/4/25/sorry-dcand-baltimore-no-periodical-cicadas-for-you-this-year-imagicicadai-spp).
Another unusual phenomenon of periodical cicadas is what is referred to as “stragglers”. Stragglers are
periodical cicadas that emerge in years prior to or after their brood is expected to emerge. Usually, 17 year
cicada stragglers emerge four years prior to their expected emergence date, however it is possible for periodical
cicadas to emerge between 8 years earlier and 4 years later than expected. Based on historical data, researchers
can associate stragglers with their massive parent brood. This year curious unknown stragglers, perhaps from
Brood II or Brood X, have shown up in a few locations rather far removed in space or time from the rest of their
crew. For example, we have heard reports of adult periodical cicadas in Rockville and Ellicott City – which
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would make them one of the rare straggler events. This wonderful and surprising event has entomologists in
frenzy as it may add new information to our knowledge of these unique creatures. Researchers of periodical
cicada are very interested in collecting data on the occurrence of periodical cicadas in our area.
PLEASE REPORT ANY PERIODICAL CICADAS YOU SEE!!!
Researchers maintain a web site where they would like all those who sight periodical cicadas to report what
they see (adults or nymphs) and where (as specific as possible), and if they are hearing cicadas singing in the
trees. This is especially important since people are reporting straggler cicadas in areas that are rare and unusual.
All periodical cicada reports would be helpful, can be done on-line, and it will only take few minutes.
To report Periodical cicada sightings go to: http://www.magicicada.org/report/report.php
Enjoy this unique and sensational biological event!
Ginkgo - What's Up?
By: Stanton Gill
At the May 19th IPM Pest Walk at Hood College, several people noted the strange small leaf emergence on
the ginkgo trees on the campus. Several have seen this situation in different landscapes. A tree may have fully
expanded leaves on a branch and many small leaves present. I looked at several cultivars of ginkgo at my farm
and am seeing similar strange leaf growth. The trees appear to be healthy. I think the cool wet spring is keeping
the leaves from fully expanding. As it warms up, tree foliage should grow out and expand to normal size.
Unusual Growth on Dwarf Alberta Spruce
The dwarf Alberta spruce is a mutant of the larger Alberta white spruce.
Often in older trees, the dwarf Alberta spruce will revert to the longer
needles faster growth of the Alberta white spruce. To keep the dwarf
characteristics, it is necessary to prune just below the area where the
revertant branch begins.
When you see branches of dwarf Alberta
spruce revert to the Alberta white spruce,
prune out the vigorously growing branch(es)
Woodpecker Activity
We have been receiving many reports of woodpecker activity
(a lot of yellow-bellied sapsucker reports) this spring. Here is
a woodpecker helping with insect control by feeding on a larva
in a tree.
This woodpecker is feeding on a larva
that has bored into the tree
Photo: Malcom (Mick) Thomas
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Monitoring Soft Scale
By: Nancy Harding
Fletcher scale (Parthenolecanium fletcheri)
Found females scales with eggs but no crawlers as of yet on bald cypress (Taxodium distichum) in College Park.
Oak lecanium scale (Parthenolecanium quercifex)
Found females chocked full of eggs but no crawlers on willow oak (Quercus phellos) in College Park.
Predatory lady beetle larvae were also found. See “Beneficial of the Week” below.
Pulvinaria scale (likely Cottony maple scale, Pulvinaria innumerabilis)
Female scales with their cottony ovisacs (waxy substance containing eggs) were found on azalea this week in
in nothern Virginia by Craig Greco, Yardbirds, Inc.. Pulvinaria scales are a type of soft scale where the adult
female produces a very noticeable cottony ovisac that appears to “trail” behind her body. The accumulated
degree days in College Park on Wednesday, May 25 was 511DD. We will continue to monitor these scales and
report when egg hatch (crawlers) occurs as this is the stage to target for control.
Soft Scale Life cycle: Most species of soft scale have
similar life cycles. Female soft scales may be smooth and
usually are hemispherical shaped. Soft scales do not have
hard waxy “covers” like armored scales. What you see
is the actual body of the soft scale. Most immature soft
scales (crawlers that hatch from eggs) retain their barely
visible legs and antennae and will crawl directly to leaves
where they line up along the mid-vein and then spend
most of the summer feeding and excreting honeydew.
Many ants may be found tending to the scales to protect
them from natural enemies. Ants benefit by feeding on Typical life cycle of a soft scale insect (family
Coccidae).
the honeydew produced by the soft scale. The scales
Illustration by S. Dreistadt.
will return to the twigs and bark where they will spend
the winter as settled scales. In the spring, scales feed heavily on the phloem sap of their host tree, and they will
continue to develop to adulthood when winged males mate with wingless females. Females will produce eggs
which she keeps under her body, causing her to swell or hump up, or as with pulvinaria soft scale will produce
a waxy ovisac where her eggs can be found. A single female may lay up to 1,000 eggs. Soft scales have 1
generation per year. See the diagram.
Monitoring: Now is the time to monitor soft scales for the presence of females with eggs or crawler activity
(recently hatched eggs). Flip soft scale bodies over and look for eggs or just hatched eggs where crawlers are
beginning to move. Look for cottony ovisacs of pulvinaria scales.
Management: There are many predators (see “Beneficial of the Week” below) and parasitoids that attack
soft scales providing biological controls. Therefore, control measures are usually not needed. If honeydew /
sooty mold is abundant control measures may be warranted. For best control target the crawler stage (recently
hatched eggs) of the scale. As noted above crawlers should be active soon for a number of soft scale species.
Horticultural oil should provide suppression of the scale and be the least harmful to natural enemies. Since oil
kills by contact be sure to get thorough coverage of the plant tissue where scales are present.
Note From Stanton Gill: Need Scale Insect Samples
The cool weather has slowed down soft and armored scale development this spring. If you have skip laurel with
white prunicola scale, lecanium scale on anything, or cottony taxus/camellia scale, please send me samples at
UMD-CMREC, 11975 Homewood Road, Ellicott City, MD 21042. Let me know the location from which you
took the sample. I will flip over scale covers under the scope to see where we are in the development stages.
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Beneficial of the Week
By: Paula Shrewsbury
Looks like a mealybug, but really it’s a predatory lady beetle larva feeding on soft scales
Soft scales can be key pests causing damage
to ornamental trees, usually by producing an
abundance of honey dew, especially at this time of
year. As mentioned above, several species of soft
scales have laid their eggs which should be hatching
shortly. Adult female scales can be found on the
twigs of their host tree. If you flip their bodies over
you will see hundreds to a thousand eggs under the
body of each scale – yikes! Fortunately, Mother
Nature has also provided us with parasitoids and
predators that like to feed on soft scales and their
eggs. In the last week or so you might have noticed
white wax-covered insects crawling around on scale
infested twigs and wondered what they are. They
A Hyperaspis lady beetle adult is foraging for prey among a
are the larvae of predatory lady beetles that tend
cluster of tulip tree soft scales
to specialize on soft scales. Lady beetles (a.k.a.
Photo: M. J. Raupp, UMD
ladybugs or ladybird beetles) belong to the beetle
family Coccinellidae. When we first hear mention
of lady beetles, our minds picture beetles that are
red with black spots. However, members of the
coccinellid family are quite diverse. Lady beetles
range in size, color, and appearance both as adults
and larvae, in addition to their preferred prey items.
The immature stage of lady beetles that feed
on scale insects often produces a white waxy
covering from special glands on their bodies (tribe
Scymnini). There are multiple genera and species
in this group. One of the more common soft scale
predators I see in MD is a black lady beetle with
two large red spots on its elytra (wings), referred
The larval stage of Hyperaspis lady beetles produce a waxy
to as the Hyperaspis lady beetle, and is about 1/8” covering. At first glance they are often mistaken for plant
feeding mealybugs.
in size. There are actually numerous species of
lady beetles in the genus Hyperaspis and they vary Photo: M. J. Raupp, UMD
in their number and color of spots. Most are dark
colored with red, orange, and/or white spots. The larvae have special glands that produce wax which coats its
body. Research has shown that the wax covering helps to reduce the effectiveness of ants and other predators
that might like to munch on a lady beetle. Hyperaspis lady beetles, both adult and larval stages, are common
predators that each feed on thousands of scale insects (and also mealybugs) throughout the beetles development.
The larvae are often mistaken for mealybugs. The easiest method to distinguish the predatory beetle larva
(good guy) from the pest mealybug (bad guy) is to look at their mouthparts, beetles have chewing mouthparts
and mealybugs have sucking mouthparts. Also if you poke them the larvae, lady beetles will move away when
disturbed, while the mealybugs will likely stay in place. It is also a good bet that if you see these white waxy
insects on trees infested with soft scale they are predators there to enjoy a meal or two. When you have scale
infested trees and shrubs, be sure to scout for these ladybeetle adults and larvae. Take precautions to conserve
6
them by avoiding the use of pesticides, especially broad
spectrum long residual products (ex. pyrethroids). If populations
are high and causing excessive damage I would recommend
treating the crawler stage with horticultural oil which should not
back the scale population while doing little harm to the natural
enemies. These lady beetles, often in combination with scale
parasitoids, are helping to suppress soft scale infestations.
The larval stage of a predatory lady beetle was found this week
with its body snuggled under an oak lecanium scale feeding on
scale eggs. Note the scale eggs that were picked up during the
lady beetles feeding frenzy.
Photo: N. Harding, UMD
Weed of the Week
By: Chuck Schuster
The rains have slowed or stopped, and the
sun has come out. From cool temperatures to
warm/hot temperatures, weeds are now in an
accelerated mode. Everything is growing much
faster now and it’s time to test your ability to
keep up.
False parsley, Aethusa cynapium, also called
fools parsley, is blooming in some areas now.
This annual, and sometimes biennial, is in the
Apiaceae family. It is from Europe, West Asia
and Africa and is related to water- dropwort
and hemlock, and is poisonous. Found in field
edges and in landscapes, it will grow thirty-six
to forty-eight inches in height, with branched
stems, alternate leaves, and a glossy appearance.
Leaves are angular, 2-3 times pinnate, lobed
and stalked. Flowers are white with 5 petals
that are small, less than one quarter inch wide,
occurring as a compound umbel. The root is a
white taproot. This plant can be found in field
edges and landscapes where soils are moist and
nutrient rich. Similar to hemlock, fools parlsey
has a much narrower leaflet.
False parsely,
also called
fool’s parsley is
poisonous; look for
it in bloom now
Photos: Chuck
Schuster, UMD
Control of this plant can be achieved by mechanical means through
pulling. Leaving any portion of the taproot will allow it to regrow.
Preventing flower development will prevent seed production for the
following year. it does not tolerate close mowing. Chemical control in
the landscape can include Burnout and Glyphosate products, as well
as 2,4D and Dicamba products.
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Plant of the Week
By: Ginny Rosenkranz
Physocarpus opulifolius ‘Mindia’ or Coppertina™, ninebark, is a native shrub that grows 6-8 feet tall and wide
in a free branching compact mound. The name Coppertina is for the bright bronzy copper-orange foliage in
the spring that matures to red in summer. The serrated, 3-lobed leaves look a bit like Viburnum opulus or the
European cranberry bush. The bark of mature plants exfoliates into long thin strips to reveal layers of reddish
to light brown, giving winter interest. The small 5-petaled light pink to white flowers are clustered together
in a round bouquet about 2 inches across and bloom in the late spring. Plants are hardy from USDA zone 3-7
and grow best in moist soils but will tolerate drought conditions once established. Plants are tolerant to both
acidic and alkaline soils and grow well even in harsh conditions. Coppertina™ can be planted in containers,
as a specimen plant, used in a shrub border, for screening and for erosion control on stream banks. Cut flower
growers also grow it was a woody cut stem. The plant is susceptible to leaf spots, powdery mildew and fire
blight.
The copper foliage of Ninebark Coppertina becomes red in summer
Photos: Ginny Rosenkranz, UME
Plant Phenology Indicators
PLANT
Baptisia australis ‘Blue Smoke’
Stewartia pseudocamellia
PLANT STAGE (Bud with color,
First bloom, Full bloom, First leaf)
Full bloom
Bud
8
LOCATION
Ellicott City (May 25)
Ellicott City (May 27)
Degree Days (As of May 25)
Annapolis Naval Academy (KNAK)
521
Baltimore, MD (KBWI) College Park (KCGS)
518
Dulles Airport (KIAD) Ellicott City (E3247)
485
Fairfax, VA (D4092)
Frederick (KFDK)
396
Greater Cumberland Reg (KCBE) Gaithersburg (KGAI)
436
Martinsburg, WV (C1672)
Natl Arboretum.Reagan Natl (KDCA)
700
Rockville (C2057)
Salisbury/Ocean City (KSBY)
548
St. Mary’s City (St. Inigoes, MD-KNUI)
Westminster (KDMW)
497
Important Note: We are now using the Online Phenology and Degree-Day Models site.
518
526
621
485
458
638
665
Use the following information to calculate GDD for your site at the Online Phenology and Degree-Day Models site: Select your
location from the map
Model Category: All models
Select Degree-day calculator
Thresholds in: Fahrenheit F
Lower: 50
Upper: 95
Calculation type: simple average/growing dds
Start: Jan 1
Once you know the GDD and / or plant phenological indicators (PPI, what plants are blooming) in your location, you can go to the
Pest Predictive Calendar to determine what pests you can expect to be active soon in that location.
Biocontrol Conference for Nursery and Greenhouse Growers
By: Stanton Gill
We are organizing a Biocontrol conference for August 18, 2016, so mark your calendar. We will put out
a complete schedule of topics and speakers in June. The location will be Brookside Gardens in Wheaton,
Maryland.
We will be bringing in speakers from the Ontario Experiment Station, the Connecticut Experiment Station,
BioWorks from Florida, local growers who have adopted biocontrol options, and several University of
Maryland Extension faculty. Each will talk about their latest research in biological control options in the
nursery, greenhouse and landscape. This program is co-sponsored with MNLGA and they will handle
registration for this conference.
A New Biofungicide: Olympic Horticulture Products announced last week that they are marketing a
biofungicide/bactericide under the name Triathlon. It is an aqueous solution material, which colonizes plant
surfaces and prevents the establishment of disease causing fungi and bacteria. With the active ingredient,
Bacillus amyloliquefaciens, Triathlon BA provides preventive control of many foliar and soil-borne diseases
such as botrytis, powdery mildew, downy mildew, rusts, leaf spots, alternaria, pythium, phytophthora,
rhizoctonia, fusarium and bacterial spot. Chris Hayes, BioWorks, will cover this product and others for
biocontrol of fungal diseases at the August 18th Biocontrol Conference.
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Commercial Horticulture Conferences
Pesticide Recertification Conference (Eastern Shore)
June 3, 2016
Register on-line
US DOT Forum
June 8, 2016: 8:00 a.m. to noon
Location: 6772 Rockawalkin RD, Hebron, MD
Contact Ginny Rosenkranz, Extension Educator, 410-749-6141 to sign up for this free US DOT Forum
Pesticide Recertification Conference
June 10, 2016
Location: Montgomery County Extension Office, Derwood, MD
Brochure is posted online
MNLGA Nursery Field Day
June 23, 2016
Location: Angelica Nurseries 11129 Locust Grove Road Kennedyville, Maryland 21645
Contact: 410-823-8684, [email protected]
Hops and Drones
June 29, 2016, 4:00 PM - 8:00 PM
Location: Milkhouse Brewery at Stillpoint Farm 8253 Dollyhyde Road Mt. Airy, MD 21771
Contact: 410-823-8684, [email protected]
Maryland Christmas Tree Association Summer Meeting
Saturday June 25, 2016 at Thomas Tree Farm, 3501 Hanover Pike, Manchester, MD
For info: [email protected]
Hands-on Perennials Diagnostic Workshop
July 20, 2016
Location: Perennial Farm 12017 Glen Arm Road Glen Arm, MD 21057
Contact: 410-823-8684, [email protected]
Biological Control for Greenhouses and Nurseries
August 18, 2016
Location: Brookside Gardens, 1800 Glenallan Avenue, Wheaton, MD 20902
Contact: 410-823-8684, [email protected]
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IPMnet Has a New On-line Tool: The Pest Predictive Calendar
This Pest Predictive Calendar is intended to assist landscape managers, growers, IPM professionals and
others in predicting the appearance of pest insects and mites in order to make more timely management
decisions. By using the Plant Phenology Indicators (PPI) and Growing Degree Days (GDD) on this table you
can anticipate when the susceptible life stage(s) (stage you want to target for control measures of pest insects
and mites are active.
CONTRIBUTORS:
Stanton Gill
Extension Specialist
[email protected]
410-868-9400 (cell)
David Clement
Plant Pathologist
[email protected]
Paula Shrewsbury
Extension Specialist
[email protected]
Andrew Ristvey
Extension Specialist
[email protected]
Karen Rane
Plant Pathologist
[email protected]
Ginny Rosenkranz
Extension Educator
[email protected]
Chuck Schuster
Extension Educator
[email protected]
Nancy Harding
Faculty Research
Assistant
Thank you to the Maryland Arborist Association, the Landscape Contractors Association of MD, D.C. and VA, the
Maryland Nursery and Landscape Association, Professional Grounds Management Society, and FALCAN for your
financial support in making these weekly reports possible.
Photos are by Suzanne Klick or Stanton Gill unless stated otherwise.
The information given herein is supplied with the understanding that no discrimination is intended and no
endorsement by University of Maryland Extension is implied.
University of Maryland Extension programs are open to all citizens without regard to race, color, gender,
disability, religion, age, sexual orientation, marital or parental status, or national origin.