|
 The star of the day was less than two inches long, and its costars were as tiny as a quarter of an inch. But they fully captured the attention of the dozen children participating in the butterfly workshop at Royersford Public Library.
Led by children’s librarian Nancy Niggel, the two-session workshop taught children about the life cycle of the monarch butterfly. The youngsters also received sprigs of milkweed and a few leaves containing eggs and tiny caterpillars.
Before the live critters were introduced, though, the children participated in a discussion of the stages in a butterfly’s life.
Niggel explained that butterflies lay their eggs on the plant the caterpillar will eat. Monarchs are the only butterflies which use milkweed. In contrast, swallowtails lay their eggs on Queen Anne’s lace, except the spicebush swallowtail which, of course, uses spicebush.
After about five days, the caterpillars hatch out of the eggs. They eat the milkweed leaves and grow rapidly, shedding and eating their skin five times as they grow from less than a quarter of an inch to nearly two inches in about two weeks.
The caterpillar then forms a chrysalis, and a week or so later, the butterfly emerges. The emerging butterfly is already an adult, Niggel stressed, and a butterfly, even fresh from its chrysalis, is never a baby. “The baby of a butterfly is a caterpillar,” chimed in one of the children.
When the caterpillar is ready to form its chrysalis, it hangs upside down in the shape of a J. The actual transformation into a chrysalis takes only a few minutes, Niggel said, but although one of her caterpillars was hanging in position, it didn’t oblige the children by forming its chrysalis during the workshop.
Niggel stressed that an emerging butterfly cannot be helped out of its chrysalis. Handling the chrysalis before the butterfly emerges can cause irreversible – and even fatal - damage to the insect’s wings.
The children were taught how to pick up and move the caterpillar, especially when cleaning its home. The best home habitat for the caterpillar, according to Niggel, is to put a stalk of milkweed in a glass or jar, then place that in a larger, paper towel lined container such as an old aquarium.
She advised the children they would need to pick lots of milkweed to feed their caterpillars, and they would need to clean the caterpillars’ homes often, removing the “frass,” the technical term for caterpillar poop.
Niggel, who lives in Limerick, began raising monarch butterflies when her son was 4. He’s 10 now, and they’ve been doing it each year. “It’s really a blast,” she told the children. “You’re going to want to do this every summer.”
Niggel grew up in Skippack and always saw lots of monarchs. “I think that must be directly on their migration path,” she remarked, and she thinks that’s why she finds so many caterpillars and eggs in the Skippack area.
The monarch, the only tropical butterfly that comes this far north, actually goes through two life cycles in one year. The caterpillars that are hatching now will grow into the butterflies which make the famous trek to Mexico for the winter.
In the spring, these butterflies will fly to the southern part of the United States, where they will lay eggs and a new brood will hatch. Those butterflies are the ones now laying eggs in this area, and when these caterpillars emerge as butterflies, they will have an extra supply of fat which will enable them to make the trip to Mexico.
The caterpillars the children will raise this month are actually “the grandchildren of the monarchs from last September,” Niggel said.
Niggel wrapped up the workshop with a craft and snack, and she encouraged the children to check out library books on butterflies as the youngsters eagerly lined up to receive caterpillars and eggs to take home.
In the second session of the workshop, the children learned how to tag the butterflies, which enables scientists to study the migration patterns of the monarchs. “I thought that only scientists tagged monarchs,” Niggel remarked, but a few years ago she learned how easy it is for anyone to do.
Butterflies are not as delicate as people think, Niggel said. In fact, if a butterfly has a broken wing, “you can actually scotch tape (the wing) together and it will do fine,” she noted.
Adult butterflies drink flower nectar, although captured butterflies can be fed watermelon or rotten bananas,Niggel said.
|