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Monarchs Will Soon Leave for Mexico
FOR IMMEDIATE RELEASE September 18, 2012
The monarch butterfly is one of the most recognizable
insects in Illinois. In 1975 it
officially became our state insect thanks to a class of elementary students in
Decatur, Illinois. Actually, many states
recognize the monarch as either their state insect or butterfly. People often separate butterflies from their
other insect counterparts. It is no
wonder as butterflies, and specifically our precious monarch, are held in such
high regard. The monarch is beautiful,
graceful, and capable of migrating to a warmer climate to sustain the species.
Butterflies go through complete metamorphosis. This means there are four stages to the life
cycle. The adult lays an egg on
milkweed, which is the specific host plant for the monarch. The egg hatches after three to four days and
the larva, we often refer to as a caterpillar, then begins a two week feast on
the host plant and shedding its skin, or molting, five separate times. Each molting is referred to as an "instar".
The caterpillar, or larva, is quite large by the time it
reaches the 5th instar and travels off the host plant to another
location. It then makes a silk pad to
hold on to during the final molt leading into the pupa stage for ten to
fourteen days. This is called a
chrysalis. Peggy Doty, University of Illinois Extension Educator reminds us,
"If we were discussing moths, this pupa stage would be called a cocoon." The pupa leads to the completion of the life
cycle and the adult monarch emerges. The
complete metamorphosis of the monarch takes approximately 30 days to complete.
The last monarchs of the summer leave around October and
head south to the mountains of central Mexico.
The monarchs that you will see in early spring will not be these
monarchs but the offspring of our fall migrants. When the monarchs migrate back north they lay
eggs in the southern United States as they travel. The adults actually expire before they reach
Illinois. It is their children and often
their grandchildren who have completed the journey back home. These offspring
are the monarchs you encounter in your gardens in the spring. They will lay eggs and the cycle will
continue all summer until the last ones emerge and fly south again. "It would obviously be more adventurous for
the late monarch as it gets to travel and vacation in Mexico, "said Doty. Doty goes on to say, "In 1991 central Mexico
experienced severe weather with storms and very low temperatures. A large number of the migrant monarch
population was blown to the ground and died of what we would call hypothermia
due to being wet and cold. Interesting
enough as they shoveled up the piles of monarchs those on the bottom were still
alive being insulated by the others."
Monarchs are tagged with tiny wing tags so scientists can track them and
note any changes. The purpose for
collecting all those dead butterflies was to identify any of those with tags. Some scientists feel we have yet to see the
numbers of monarchs we had prior to this devastating event.
You can do simple things to help our monarchs continue to
rebuild their population. You can plant
a butterfly garden filled with host specific plants which supply food for the
larva and nectar for the adults. Create
a safe watering area for your butterflies by wetting open soil areas each day
or putting water and pea gravel in a shallow dish with the water level just
below the gravel. "Butterflies do not
want anything to do with open or moving water," said Peggy Doty. Doty also said, "It would help the monarchs
tremendously if we would encourage milkweed to grow in our yards or gardens as
it is the only plant the monarch will use to lay her eggs and it is the only
food the larva will eat." University of
Illinois Extension will be offering a spring butterfly and hummingbird
gardening class. You can watch for this
and other interesting workshops at Extension's web site by going to
web.extension.illinois.edu./bdo. For more information on the migration of monarchs
go to Monarch Watch at www. monarchwatch.org.
Source: Peggy Doty, Extension Educator, Energy and Environmental Stewardship, psdoty@uiuc.edu |