Each fall, monarch butterflies journey from Pennsylvania and points
north all the way down to Mexico. No other insect in the world migrates
as far, and the butterflies that return in the spring will actually
be the great-grandchildren of the monarchs now heading south. Brad
Linder has more.
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Flight of the Monarch
It's that time of year again, the Monarchs are migrating.
October 8, 2002
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by Dan Simon
While Monarch butterflies feed on a variety of plants, there's one
central plant, Milkweed, that's critical to their lifespan.
Monarch butterflies use small hooks to latch on to trees,
plants and grasses. ©GreenWorks photo by Dan Simon.
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Milkweed, a fairly common weed that's been banished from most gardens,
is the only type of plant a female Monarch butterfly will use to lay
her eggs. Since the plant is a hardy and tenacious weed, it's not
likely to be threatened by not being included in your backyard garden.
The plant does thrive in vacant lots and along roadsides.
Still, as more and more development fills in those vacant lots and
open spaces, it makes a mother Monarch's job harder. This is especially
true when you consider her preference for laying only one egg on each
plant (good for the plant's health, not so good for mom's). This preference
means the butterfly has to spend a lot of time finding plants to deposit
her many eggs on (she may lay more than 400 eggs).
Some people do go so far as to plant Milkweed, both to help and attract
the orange and black butterflies. In this part of the country, Milkweed
is probably more of an annual plant than a perennial because of our
cold winters.
Monarchs are tagged with a lightweight tag that doesn't
interfere with their ability to fly. ©GreenWorks photo
by Lisa Simon.
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Milkweed is a toxic plant. As the caterpillars eat it, they become
poisonous to other animals. Scientists have learned that birds will
be repelled by a Monarch's taste and will subsequently avoid the butterfly
in future hunts.
Other animals frequently take advantage of such situations by mimicking
the characteristics of the poisonous creature. For instance, there's
a type of moth that looks very much like the Monarch butterfly. As
a result, birds frequently leave the moth alone, thinking it's also
a bad-tasting Monarch. (To tell the difference between the two, the
Monarch has a black body with white spots, the moth has a brownish,
hairy body without the spots).
Adult Monarch butterflies feed on a variety of nectar producing plants.
Some popular types for this region include the Purple Coneflower,
Snapdragons, Zinnea and Butterfly Bush. Azaleas and Lilacs are other
good bush-type plants for attracting butterflies.
A tagged Monarch butterfly roosts in a tree after being
released. ©GreenWorks photo by Dan Simon.
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If you do plant a butterfly garden, be careful with pesticides, many
of which are as fatal to beneficial insects as garden pests. Check
labels to see if a particular pesticide can be used in an area where
you're hoping to attract butterflies.
Some experts fear the widespread spraying of pesticides to combat
the West Nile Virus may also affect Monarch populations as the butterflies
migrate south. While the total population of these insects probably
reached well over a billion last year, between the freeze in Mexico,
the drought and increased insecticide spraying, the fear is this year's
Monarch count will be significantly lower than last year's.
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