The Kingdom of Monarchs

Monday, April 16, 2007

Would you like to eat the same thing every day, for every meal? Let's say that for breakfast you eat an apple. Then you go to school and the only food in the cafeteria is apples. Back at home, you have an apple for a snack, two apples for dinner and an apple before bed.

If you were a monarch caterpillar, you wouldn't mind eating the same thing every day. Monarch caterpillars eat only one type of plant: milkweed. The scientific name for this group of plants is Asclepias (pronounced ah-SKLEE-pee-us).

Starting late this month and continuing through the summer, monarch butterflies will be in the Washington area. The adults feed on many nectar plants, but the females must lay their eggs on milkweed, their "host plant." And it's getting tougher every year for them to find some.

Wild milkweed grows in fields and along roadsides. But if you look around your neighborhood, what do you see? Perhaps parking lots and lawns sprayed with weed killer. Not a milkweed plant in sight.

Some people help the monarchs by growing milkweed in their gardens. You can buy seeds of Asclepias tuberosa -- also called butterfly weed or butterfly flower -- at local garden centers. Plant the seeds in a sunny spot. During the summer, see if any monarch butterflies visit. One might be a female laying an egg on your milkweed.

Every so often, especially in August, check your milkweed for black-and-yellow-and-white-striped caterpillars. You can look for their frass (poop). Frass from the youngest "cats" looks like pepper; bigger cats produce bigger pellets. When you see frass on a leaf, crouch down and look up at the undersides of the leaves.

Fewer than 10 percent of monarch caterpillars in the wild survive to become butterflies. But if they are brought inside, given fresh milkweed every day and handled very little, most will live to become butterflies.

A caterpillar molts five times as it grows. It crawls out of its old skin, then eats it. Before the fifth molt, the caterpillar finds a quiet place where it can hang upside down. This might be the underside of a leaf, a garden bench or the ceiling of its cage if it's indoors.

The last molt reveals the jade-green pupa, or chrysalis.

In 10 to 14 days, the chrysalis will look dark. The butterfly will eclose (emerge) that morning. September butterflies will head to Mexico for the winter.

-- Marie McCarren

© 2007 The Washington Post Company