Dicamba drifts. Apparently, more than expected by a lot of farmers, agriculture officials and manufacturers. But does that mean, as the Center for Biological Diversity claimed recently, that the herbicide is hurting migrating Monarch butterflies?
According to figures gathered by the University of Missouri, about 3.6 million acres of soybean were damaged in 2017 by drifts of dicamba, accounting for 2,708 dicamba-related damage reports. About a third were in Arkansas, but the rest ran through the center of the country (except Texas) and the Midwest, Southeast and Middle Atlantic. These figures were behind several movements by state agricultural officials to either ban the herbicide or limit its application. They also factor into several lawsuits against Monsanto and DuPont, companies that have developed new lines of soybeans engineered to work with the herbicide.
As luck would have it, the dicamba-damaged areas are in prime Monarch migration territory.
So, the Center for Biological Diversity issued a report in late February, “Menace To Monarchs,” looking at the correlation between dicamba use and drift, and Monarch migrations. The center’s report concluded that dicamba could erect significant barriers to migrating butterflies making their way north in the summer and south in the fall. The damage, according to CBD, comes mainly from the weed-killer’s ability to kill off milkweed, a plant essential for furthering the growth of Monarch larvae.
The report predicted that 60 million pounds of dicamba could be used in 2018, particularly on tolerant soybeans and cotton, and called for the US Environmental Protection Agency to let a two-year registration for use on GM soy and cotton expire this year. “We’re not calling for an outright ban on dicamba, but we don’t believe that it can be used safely on