archs more vulnerable to weather. Villagers use
the trees as fuel and for income. Monarch tourism can partly but not completely make up for
income lost from logging.
Helping Monarchs
There are a number of ways we can help monarchs survive.
Plant a Butterfly Garden:
Butterflies need shelter, sunlight, water, and food
for larva and adults.
Monarch caterpillars need milkweed. If you think
common milkweed is ugly or a weed, there are
many different kinds of milkweed, some more
ornamental and less invasive. But plant lots and
be prepared to accept damage to plants - caterpillars are voracious eaters.
Adults feed on nectar, which can be provided by
a wide variety of flowering plants. Have something in bloom at all times, plant in blocks or
sweeps of a single color rather than individual
plants, and consider using native plants. A few
nectar plants include aster, bee balm, coneflower, goldenrod, Joe Pye weed, liatris, milkweed,
phlox, rudbeckia, sedum, and sunflower (all perennials) and ageratum, cosmos, lantana, marigold, pentas, tithonia, and zinnia (annuals).
Monarchs need shelter at night and during bad
weather, and places to form a chrysalis. Include
trees and shrubs in your planting, plant a windbreak, or, if possible, leave an area “natural” with
weeds, logs, brush or rock piles, etc.
Provide small areas of shallow water, natural or
in containers. Mix water with sand and soil to
provide needed minerals. Include flat stones
where butterflies can bask and soak up the sun.
Avoid use of pesticides whenever possible.
For more information on butterfly gardens see
the brochure Flying Flowers.
Information on what is needed to provide habitat
for monarchs is also available at MonarchWatch.org. This site is an excellent source on all
things monarch - providing habitat, rearing, milkweed, conservation efforts, migration, tagging,
and much more. If desired, for a small fee you
can register your butterfly garden as a Monarch
Waystation and obtain a sign to let others know
what you’re doing.
Raise Monarchs:
If you have attracted monarchs to your butterfly
garden, you might want to consider collecting
eggs and small caterpillars and raising them to
adulthood. With all the dangers to early stages
of monarchs, this can really help increase the
survival rate. This can be a fascinating project
for both children and adults. A word of warning you will need access to large quantities of milkweed - a single caterpillar can defoliate an entire
stalk of milkweed.
For more information see MonarchWatch.org.
Support Efforts to Increase Habitat:
Encourage the planting of milkweed and nectar
plants along roadsides. Discourage mowing and
spraying. Plant butterfly gardens at businesses,
schools, parks, and other public areas. If you
live in a rural area plant milkweed and nectar
plants in unused spots.
Increase Awareness:
Share information about monarchs with others.
Plan an event to raise awareness about monarchs. Register your butterfly garden as a Monarch Waystation. The story of monarchs is a
great learning tool and is already used in many
schools.
Help Scientists Learn More:
For years scientists have been placing small
tags on monarchs to learn more about their
movements. There may be an event near you
where you can see a demonstration and perhaps learn to do this.
Journey North (http://www.learner.org/jnorth/)
tracks the journey not only of monarchs but of
other migrating species. You can report sightings of monarchs at various life stages and also
the first milkweed in the spring, as well as track
events across the country.
We’ve devoted this brochure to the monarch
butterfly because its amazing story captures
everyone’s imagination. But many of the same
issues apply to all butterflies and other wildlife.
Habitat is decreasing at an alarming rate across
the country and around the world and many beneficial insect numbers are declining. Many of the
things we’ve suggested that will help the monarch also help all other types of wildlife survive.
For more information on gardening
please visit:
http://web.extension.illinois.edu/state/
horticulture/index.php
or
call University of Illinois Extension
Knox County
Monarchs
& Their
Amazing Journey
309-342-5108
Other information brochures can be found
online at http://web.extension.illinois.edu/
hkmw/hort.html
Developed and Written by
Knox County Master Gardeners
University of Illinois Extension
Knox County
September 2015
University of Illinois ~U.S. Department of
Agriculture ~ Local Extension Councils
Cooperating
University of Illinois Extension provides
equal opportunities in programs and
employment.
UNIVERSITY O F ILLINO IS EXTENS ION
HEN DE RSON, KNOX, MC DONO UG H
AND WARREN CO UNTIE S
Knox County Office
180 S. Soangetaha Rd. Suite 108
Galesburg, IL 61401
Phone:
Fax:
Email:
309-342-5108
309-342-1768
[email protected]
Garden Tips
from
Knox County
Master Gardeners
&
Master Naturalists
Across the country every year, schoolchildren learn about and celebrate monarch
butterflies and their epic journey. Older
adults may remember a time when monarchs were more plentiful, when you might
see hundreds in a meadow or roosting in a
tree. It seems everyone is captivated by
monarchs and their story.
In this brochure we’ll discuss monarch butterflies and their migration, as well as what
they need to survive and what can be done
to help them.
The Monarch Life Cycle
Monarchs (as well as all other butterflies)
go through four distinct stages. The timing
of each stage depends on temperature and
other weather conditions. The times given
are for normal summer conditions.
Egg: Female monarchs lay eggs only on
milkweed plants, usually only one per stalk.
Milkweed contains toxins that gives caterpillars and adults a bad taste and helps
deter some predators, especially birds.
After 3-5 days the top of the egg turns
black and the caterpillar emerges. Females can lay 300-500 eggs during their
lifetime. As few as 1% will reach adulthood
in the wild.
Caterpillar (Larva): The caterpillar’s job is
to eat and grow bigger. It will shed its skin
(molt) 5 times to allow for growth. Milky
white at first, it later develops black and
yellow stripes. After 9-14 days, it looks for
a sheltered spot to form a chrysalis, and
then hangs upside down in a “J” before
shedding its skin for the last time, revealing
the chrysalis.
Chrysalis (Pupa): The chrysalis hardens
to a jade green case with gold dots, later
darkens, and then becomes transparent
just before the butterfly emerges. This
stage usually lasts 10-14 days. The butterfly often will not emerge until conditions are
right, usually in the morning on a warm
sunny day.
Adult: The adult emerges (ecloses) from
the chrysalis with small, folded wings. Flu-
id is then pumped from the enlarged abdomen to
expand the wings, and the butterfly clings to the
chrysalis case as the wings dry and harden (a
few hours to a day depending on the weather).
Monarchs that emerge in June, July, and August
are sexually mature within 3 days, mate soon
after, and have a 4-5 week lifespan. Monarchs
are cold-blooded and rely on the sun for warmth.
They fly only during warm sunny weather.
The Migration
Monarchs are native to tropical areas of the New
World, and milkweed was originally a tropical
plant. After the last Ice Age the range of milkweed gradually moved north and the monarchs
followed it in search of places to lay eggs.
Most insects that live in colder regions survive
the winter by hibernating in one stage or another. However, monarchs in Central and Eastern
United States and Southern Canada return each
winter to a region of Mexico where they can survive the winter. (Monarchs west of the Rocky
Mountains overwinter in sites along the coast of
California south of San Francisco.) Some fly
almost 3000 miles in a journey that is unique
among insects.
In September monarch physiology and behavior
changes. Instead of maturing and reproducing
the adults begin the long journey south. Instead
of living 4-5 weeks they will live 7-9 months.
They can fly 10-20 miles per hour, catching rides
on wind currents far above the earth, and traveling up to 80 miles per day. They fly only in good
weather and roost on trees or bushes at night.
They eat as much as they can before they start,
and feed on nectar along the route - they need
to accumulate fat stores so they can survive the
winter and begin their journey back. As they get
further south they form huge migrating clusters
as they funnel through a 50 mile wide area in
Texas.
The monarchs spend the winter in oyamel fir
forests high in the mountains west of Mexico
City. Very specific conditions are required. It
must be cold enough so they can remain semidormant to conserve energy but not so cold that
they freeze, and humid enough to keep them
from dehydrating, but with protection from rain
and snow that can be lethal when combined with
cold temperatures.
When they reach the overwintering sites they cover the trunks and branches of the trees and often
the ground. They don’t eat but may seek water
on warm days. While overwintering they are in
danger from predators and harsh winters - in bad
years up to 80% of some colonies have been lost.
As weather warms in spring they gradually become more active, moving down the mountainsides in search of nectar and beginning to mate
as they finally mature.
They then begin the journey north, laying eggs on
milkweed along the way. The monarchs that began the migration in the fall usually die when they
reach Texas or the Gulf States, but occasionally
make it back to their birthplace. As their children
emerge as adults they mate and continue flying
north, laying eggs along the way. This continues
until September, when the return journey begins
again.
The Mystery of Monarchs
The overwintering sites in Mexico were only recently discovered by scientists. Until 1975 people
in the United States and Canada didn’t know
where the monarchs went in the winter, and the
villagers in Mexico didn’t know where they came
from.
There is much that is still unknown about monarchs and their behavior. How and why are fall
monarchs different than those that emerge in
spring and summer? How do they know where to
go and when to leave? Adults born in Canada
and the United States find their way to a small
area in Mexico they have never seen before.
Even when moved from the Central Plains to the
East Coast as adults, they begin the journey offcourse but correct themselves within a day or two.
And on the return journey newly emerged butterflies continue flying north, some ending up in
North Dakota, some in Maine, and others everywhere in between.
Most of this is not conscious behavior but may be
triggered by temperature, day length, milkweed
quality, or the earth’s magnetic field, as well as by
other cues we may not yet be aware of.
Threats to Monarchs
Numbers of monarchs, as well as other butterflies and beneficial insects, are declining. The
number fluctuates from year to year depending
on conditions, but the trend has been downward
over the last several decades.
The biggest threat to monarchs is loss or degradation of habitat in overwintering sites, summer
ranges, and migration paths. Monarch caterpillars only feed on milkweed. If milkweed is not
present, monarchs cannot reproduce. But monarchs need more than milkweed. Abundant
nectar plants are necessary to sustain the
adults. Monarchs also need sheltered spots to
rest and to protect the chrysalis.
Habitat can become destroyed or fragmented
due to development and changing agricultural
practices. Roadsides are mowed or sprayed.
Insecticides kill monarchs at all stages. Even
sub-lethal exposure can affect their ability to
survive or reproduce. Herbicides can destroy
plants they depend on for food and shelter.
Despite protection from the milkweed toxin, insect and other predators kill many monarchs,
especially eggs and small caterpillars.
Monarchs are more vulnerable to habitat destruction than many other insects because of
the long journey they must make over a wide
variety of landscapes. They must have the
proper conditions and resources all along the
route. If habitat is missing at any place along
the way they are at risk of not completing their
journey. And drought or other problems in an
area such as Texas where they all come together can have devastating consequences.
But monarchs are resilient. With a little help
they can recover remarkably quickly from winter
losses or bad weather in their summer range.
Overwintering sites are most critical - without
these the monarch cannot survive - and they
are concentrated in a small area. Scientists are
not sure if suitable new sites are available if
current ones disappear.
Over time, changing climate may result in less
favorable conditions in the current overwintering
sites. The biggest short-term threat to the sites
is logging. Clear-cutting reduces the total area
available for overwintering sites, and selective
cutting thins the forest canopy and makes mon-