In an interview with Yale Environment 360, University of Kansas insect ecologist Orley R. “Chip” Taylor suggests that it’s likely that genetically engineered crops are largely to blame.
Monsanto first introduced Roundup-resistant soybeans in 1997, and Roundup-resistant corn a year later. By 2004, Taylor estimates that about 50% of commercial farms were using the modified seeds. About that same time the monarch population started to significantly decline.
Monarchs feed on milkweed plants, which grow wild in the Midwest alongside corn and soybean fields. Before genetically modified seed was introduced, milkweed and other weeds were controlled through tillage. Now that farmers have herbicide-resistant crops, they control weeds with herbicides. According to Taylor, since 1997 the amount of herbicide used in agriculture has tripled. And the milkweed that the monarch butterflies depend on has all but disappeared.
The good news, if there is any here, is that the US Department of Agriculture announced May 10th that it’s ordered additional environmental impact statements herbicide-resistant crops that have been waiting for federal approval. Monsanto has developed corn, soy, and cotton resistant to two additional pesticides, 2,4-D (produced by Dow) and dicamba (produced by Monsanto).
It’s worth noting that 2,4-D was an ingredient in Agent Orange, a chemical defoliant produced by Monsanto and Dow that was used extensively in the Vietnam War. Agent Orange was later shown to cause cancer, birth defects, and other health problems in people on both sides who came into contact with it during the war. Currently the U.S. Department of Veterans Affairs lists prostate cancer, respiratory cancers, multiple myeloma, type II diabetes, Hodgkin’s disease, non-Hodgkin’s lymphoma, soft tissue sarcoma, chloracne, porphyria cutanea tarda, peripheral neuropathy, chronic lymphocytic leukemia, B cell leukemias, Parkinson’s disease, ischemic heart disease, and spina bifida in children of veterans exposed to Agent Orange as conditions associated with exposure to the herbicide.
According to Tom Philpott, writing in Mother Jones, “the move appears to be a result of the popular opposition caused by previous USDA announcements about its intention to approve the crops. In its press release, USDA noted that it had received “8,200 comments, including petitions signed by more than 400,000 people” in response to its proposal to approve 2,4-D corn.”
Good to know that signing petitions still makes a difference. Unfortunately, even if the USDA doesn’t ultimately approve Monsanto’s new herbicide-resistant products, that’s not going to help the monarch butterfly. Unless someone develops Roundup-resistant milkweed.