The study revealed that the eradication program saved U.S. cotton grower’s $192 million from 2014 to 2019. The proteins in Bt cotton kill pink bollworm and other caterpillar pests but are harmless to people and most beneficial insects.
Although Bt cotton kills essentially 100% of susceptible pink bollworm caterpillars, the pest rapidly evolved resistance to Bt proteins in laboratory experiments at the University of Arizona and in Bt cotton fields in India.
To delay pest resistance, Uarizona scientists worked with farmers to develop and implement a strategy of planting non-Bt cotton refuges to allow the survival of susceptible insects. For the first time since the pest’s arrival, eradication seemed within grasp.
In addition to traditional pest control tactics, such as plowing cotton fields after harvest to reduce the pest’s overwintering survival, a novel strategy largely replacing refuges of non-Bt cotton with mass releases of sterile pink bollworm moths was initiated in Arizona in 2006.
The sterile moths were released from airplanes by the billions to overwhelm field populations of the pest.
For much of the past century, the invasive pink bollworm wreaked havoc in the southwestern United States and northern Mexico — inflicting tens of millions of dollars in damage annually to cotton on both sides of the border. According to a new study to be published in Proceedings of the National Academy of Sciences,
A multifaceted strategy combining genetically engineered cotton with classical pest control tactics eradicated the pink bollworm from cotton-producing areas of the continental U.S. and Mexico,