GMO plight of the butterflies

Monarch butterflies

By Carolyn Lochhead)

The news keeps getting worse on the catastrophic decline of Monarch butterflies, now approaching a potential point of no return.

The decline has been blamed on several factors, including drought, deforestation of habitat in Mexico and a cold snap last spring in Texas. But a big reason identified definitively by entomologists is the use of genetically engineered (GMO) crops on 170 million acres along the Monarch’s migration path through the Midwest.

Corn and soybeans that have been genetically modified to resist Monsanto’s trademark Round Up herbicide have allowed farmers to use the herbicide to kill weeds very efficiently, including the milkweed that is a host plant for the Monarch. The disappearance of milkweed is a major cause of the Monarch’s decline.

In addition to destroying Monarch habitat, use of GMO crops and their accompanying herbicides have sped the evolution of so-called superweeds that are impervious to the herbicides. The Obama administration said this month that it favors approval of new crops genetically engineered to tolerate more lethal 1940s-era herbicides to attack the superweed problem. This could establish another herbicide treadmill that ecologists said will encourage the evolution of even more vigorous weeds.

Ecologists and environmentalists urge a return to more ecologically sound farming practices such as the use of cover crops and crop rotations, but this is unlikely to happen on a broad scale, given the entrenchment of genetically engineered corn and soybeans in the Midwest. Almost all these crops are genetically engineered.