Three of thirteen major pest species have become resistant to genetically modified (GMO) Bt cotton.
Issues with GMO crops—this time cotton—rear their ugly head (or perhaps that’s a multi-eyed Simpsons fish-like head?) again. It is a major crop for farmers in several countries in the world, including the United States. A recent study conducted by a team of French and U.S. scientists has shown that 3 of 13 major cotton pests have become resistant to Bt cotton (a strain that’s been genetically modified to exude a bacterium called Bacillus thuringiensis (Bt), which is toxic to insects). The research was compiled from 77 studies conducted in 8 corn and cotton producing countries and found that more 50 percent of insects had become resistant to Bt crops in any one location.
Although scientists and researchers have stated that all insects would inevitably adapt and become resistant to pesticides such as Bt (nature is wily!), many farmers have nonetheless invested in cultivating the GMO crop. Half of all Bt plantings currently occur in the U.S., where three of the resistant insect species were found, while India and South Africa account for the other plantings with resistant pests. In 2011 alone, 164 million acres of land were planted in Bt crops globally, adding to a total of over 1 billion acres that have been planted in Bt corn or cotton since the mid-1990s.
The research, which was published in the journal Nature Biotechnology, showed that providing so-called ‘refuges’ for insects that feed on cotton would slow down their resistance to Bt cotton. How does that work? An area of land adjacent to the ground where Bt cotton is grown is planted in non-Bt cotton, providing an alternative space for insects. The insects that like to eat the cotton need two copies of the Bt resistant gene to become entirely resistant to Bt crops, so planting non-Bt crops next to Bt crops means that insects have two different genes. This reduces the chances of two Bt crop-resistant insects mating and creating offspring with the completely resistant double gene. According to main author of the research paper Bruce Tabashnik, farmers should “take more stringent measures to delay resistance, such as requiring larger refuges, or this pest will probably evolve resistance quickly.” Also, it seems obvious that there’s a flaw in the design if you need a natural, non-GMO crop to counterbalance the GMO version.
The efficiency of these refuges has been demonstrated in the case of the pink bollworm, which is a caterpillar that devours the cotton boll from the inside out. In the southwestern United States, where most of the country’s cotton is grown, farmers have been working with scientists from the EPA, universities and the USDA to implement refuge strategies. The resistance of the pink bollworm has therefore developed very slowly in the US.
However, in India, where 18% of the world’s cotton is grown, this collaborative infrastructure and resource management is not available (read: the Indian farmers have less education and help to deal with GMO crops that fail). Farmers have not been able to or have not been provided with the resources to plant refuges, offering a much speedier evolution of Bt resistant pests. According to research, pink bollworms became resistant to cotton within six years in India. This only increases the already dire situation of many Indian cotton farmers, whose lives have been compromised for the sake of voluminous production of GMO cotton.
Why are we planting large quantities of Bt cotton if it is a proven fact that pests will eventually become resistant to it? Furthermore, taking advantage of less privileged farmers that cannot implement, or are not helped with effective strategies is abominable on the part of the seed-providing companies, who seemingly have nothing else in mind but profit. This is not the first case demonstrating the development of “super weeds” or “super bugs”, and will likely not be the last. In Europe, transgenic crops are opposed because of their threat to human health and the environment. What will it take for everyone to see the bigger picture?
Image: Calsidyrose