Generations of children have spent the first few weeks of school on a classic nature lesson — the metamorphosis of Monarch caterpillars into butterflies. But this year, teachers are noticing a trend that has worried naturalists for some time.
Monarch butterflies spend the winter in Mexico, then fly to the united states to lay eggs on milkweed. By summer, a generation of caterpillars start to appear in New England. In the past few years, scientists have noticed fewer Monarch butterflies making the trip — and this year, they say the population decline took a drastic turn for the worse. Entomologist Faith Deering of Florence-Massachusetts searches for Monarchs every summer.
“And usually I see dozens and dozens, and I’ve only seen 3 butterflies (this year),” she said. “The milkweed patches that I check locally that usually have caterpillars on them, having nothing on them.”
The World Wildlife Fund reported a 59 percent decline in the Monarch population last spring, so by the time teachers started to look for caterpillars for the beginning of school, the numbers were nearly zero.
Northampton kindergarten teacher Amy Meltzer usually finds caterpillars by cruising the milkweed in her neighborhood, but this year, she came up empty. So she decided to call a commercial insect supplier….who kept putting her on hold to take calls from other teachers
“I think there’s a lot of teachers who start the year hatching caterpillars, because it’s so dynamic and engaging for kids, and it’s so exciting,” said Meltzer. “And nobody’s been able to find any caterpillars.
A primary reason for the decline, Faith Deering says, is the loss of milkweed — the only food Monarch caterpillars eat. Housing development, pesticide and herbicide use have displaced the plant in the U.S and Mexico. And Deering says climate change has affected the trees where butterflies live in winter. She doesn’t expect the species to go extinct, just to stop migrating.
“It would mean eventually that we might not see Monarchs here in the New England,” said Deering.
So she hopes teachers incorporate nature conservation in their caterpillar curricula — and encourage students to plant milkweed in their own backyards.