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Index of Bugs
Monarch butterflies, whose scientific name is Danaus plexippus, belong to the
order Lepidoptera, which means scale-winged in Latin. Insects in the order
Lepidoptera have two pairs of scale-covered wings and three pairs of legs.
Monarch butterflies go through complete metamorphosis. This means that their
life cycle stages include the egg, larva (or caterpillar), pupa (chrysalis),
and adult stages.
It is easy to tell male and female Monarch butterflies apart. Males have a black spot on a vein on each hind wing. This black spot is made up of specialized scale cells that form a pouch into which a chemical is secreted. Males use this chemical to entice females during mating. Females have darker veins in their wings.
Monarchs can live wherever milkweeds (Asclepias) occur. Common Milkweed
(Asclepias syriaca), one of the main larval host plants, grows extensively on
abandoned farmland, along roadsides, and in other open areas where weedy
species grow. In the Corn Belt, milkweed is widespread in areas of native
short grass and long grass prairie, and occurs in agricultural areas within
crop fields, along roadsides, riverbanks and irrigation ditches.
Wildflowers are used as nectar sources by the Monarch butterflies. They sip liquid nectar through the proboscis, which acts like a drinking straw.
Wildflowers are therefore also an important component of Monarch habitats. They are especially important during the fall migration, when sugars obtained from nectar are converted to the fat that is essential for the butterflies to complete their migration and overwinter successfully.
The monarch is the only butterfly that migrates for very long distances like some birds do. In the late summer and early fall of each year, shorter days and cooler temperatures tell the monarch butterflies not to breed, but instead, to begin their long migration. Western Monarchs migrate to overwintering sites along the California coast. Eastern Monarchs migrate to overwintering grounds in Central Mexico, a journey of up to 3000 miles!
The monarchs that emerge in September and early October are the migrants. They will live six to eight months. Because they are the great-grandchildren of the butterflies that flew north the previous spring, they have never been to the overwintering sites in California or Central Mexico. And yet somehow, they find their way—probably through an inherited behavior pattern.
The monarchs’ overwintering sites in the forests of the mountain ranges in Central Mexico are about 10,000 feet, or 3,000 meters, above sea level. To conserve energy, the butterflies cluster on trees where the temperature is just above freezing. They cover whole tree trunks and branches. Hundreds of millions of butterflies can overwinter in Mexico in one year. By early March they fly back north in masses. The females must find early sprouts of milkweed on which to lay their eggs.
To learn more about Monarchs and to see them in action, order the Backyard Bugs DVD.
Find unique Monarch apparel and gifts at the Totally Buggin Store
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