Generations of children have learned about the miracle of metamorphosis from watching a yellow, black, and white caterpillar make a pupa and emerge 10 to 14 days later as a magnificent orange-and black-striped butterfly.
The monarch butterfly is one of nature’s most amazing creatures. In the central and eastern U.S., monarchs migrate 2,500 miles each fall to overwinter in the mountains of Mexico and then return to lay their eggs and start the cycle again. It seems unfathomable that such a fragile creature can make that flight through wind and rain and heat and cold, not just one-way, but round-trip.
Sadly, that migration may be coming to an end.
Lincoln Brower, professor emeritus of biology at Sweet Briar College and one of the world’s top experts on monarchs, sees the future in his own backyard.
“There is absolutely no breeding in our garden,” Brower said last week. This time of year, he can usually find eggs and caterpillars, but this summer he can find neither. “The whole eastern seaboard has had about no sightings at all,” he said. “This year the absence is really noticeable.”
Last summer, I counted only two monarchs and this year none. They simply have disappeared. The story is much like the one I wrote recently about our vanishing bobwhites. We have wiped out their habitat.
Monarchs lay their eggs on milkweed and it is the only plant that the larvae feed on. No milkweed, no monarchs.
Milkweed is being destroyed by monolithic agriculture, particularly in the Midwest, where soy and corn growers use genetically modified seed to tolerate herbicides that destroy other plants in their vicinity.
Efforts are underway to try to get transportation departments and utilities to allow milkweed to regenerate along roadways and power lines during the butterfly breeding season by withholding spraying and mowing. There also are efforts to require industrial agriculture to leave some strips of land unsprayed so milkweed and monarchs can survive. Brower said people need to get in touch with their legislators to demand federal action.
Brower, who has an extensive milkweed garden, encourages homeowners to plant milkweed, which can be purchased from monarchwatch.org, though as he has found, there is no guarantee monarchs will find their way to your garden.
The numbers tell why.
At least one billion monarchs once migrated to Mexico and, as recently as 1996, they wintered on 45 acres. Last year, only 35 million butterflies occupied a scant 1.65 acres in the Mexican highlands.
Bower said the species can survive, even if the two North American migrations don’t (west of the Rockies monarchs overwinter in California). There are non-migratory varieties in the Caribbean and parts of South America, as well as Florida, Hawaii, Australia and New Zealand.
But unless humans undergo a fundamental metamorphosis, future generations of North Americans may never see monarchs. What a loss that would be.