In the last few years, milkweed has spread exponentially throughout the orchard. We don’t mow it down, but we don’t plant it either. It is as if the earth herself has decided that we need more of it; that nature wants to help the monarch butterflies who depend on this plant for their survival. Every summer, monarchs lay their eggs on milkweed. The emerging black-, white-, and yellow-striped caterpillars begin eating around the edges of the leaves, and even absorb a substance from their host that provides a defense against predators.
But where are the monarchs? Their numbers have been decreasing steadily for the last twenty years. In fact, the Endangered Species Coalition reports that North American monarchs have declined by ninety percent since the mid 90’s. During the first few years of tending the orchard, I would see monarchs daily when the milkweed was in bloom. This year I have yet to see one.
One reason for their decline is the loss of milkweed habitat. Much of this acreage is now planted with corn and soybeans, and the fields are sprayed with Monsanto’s Roundup. (In 1995, 10 million pounds of Roundup was used on corn and soybeans, and, by 2013, the total pounds rose to 204 million.) Roundup destroys all weeds – including milkweed! I’ve known about the horrors of Roundup, but I didn’t realize that genetically modified corn seed, like Bt corn, produces pollen that kills monarch caterpillars and other insects. I am familiar with Bacillus thuringiensis, Bt, a bacteria-based organic pesticide that is approved for use in organic production. An organic grower uses it sparingly and for target pests. But in the case of Bt corn, the plant itself sends out this pesticide to all insects, pollinators as well as pests such as the corn borer.
When the first findings came out that Bt corn was killing off the monarchs, the agricultural giants who control the fate of millions of acres of farmland (as well as the U.S. Environmental Protection Agency and the U.S. Department of Agriculture) denied them. If you want to read further, Orion Magazine published a great article aptly titled, The Canary in the Cornfield.
In recent years, monarch butterfly decline also correlates with unprecedented fluctuations of temperatures caused by global warming. For example, in 2013, a cold period in May delayed the Monarch departure from their wintering grounds, so they arrived late and didn’t breed as well. Their numbers upon their return the following winter were the lowest ever. In early March this year, a sleet storm with high winds at their wintering ground in Mexico felled trees and buried large numbers of monarchs under sheets of ice.
It’s good we have milkweed growing throughout our orchard, and it is wonderful to read about all of the projects to encourage the survival of the monarch, like the Fresh Pond Monarch Watch in Cambridge, MA, who are planting milkweed, pulling out the invasive black swallow-wort vines, and breeding and releasing caterpillars. However, it will ultimately be the millions of acres in the Midwest that will make the most difference in monarch numbers.
Milkweed belongs to the Asclepiadaceae family, derived from Asclepius, the Greek god (actually demi-god because his father was Apollo but his mother was mortal) of medicine and healing. Athena gave Asclepius the gift to save mortals and even bring them back from the dead. Zeus was jealous when he saw his foes coming back from Hades and supposedly killed Asclepius with a thunderbolt. No one knows for sure since Asclepius became a living god. In ancient Greece there were 320 Asclepions, healing sanctuaries, actually the first hospitals in the world. Last year a 2,400-year-old temple dedicated to him was excavated. I hope he continues to use his healing powers through the proliferation of milkweed and helps to insure the survival of the Monarch butterfly.