University of Arizona entomologists and extension specialists made key contributions to the landmark achievement announced today by the USDA that pink bollworm has been eliminated from all cotton-producing areas in the continental United States — 100 years after this voracious insect was first detected here.
The UA College of Agriculture and Life Sciences and Cooperative Extension have been involved in research on the pink bollworm, one of the world’s most devastating crop pests, for decades. Before eradication, this invasive insect had often completely destroyed cotton fields, despite growers’ efforts to control them with insecticides.
“The eradication of PBW announced today is a great achievement that will benefit cotton growers throughout Arizona and the southwest,” said Bruce Tabashnik, who heads the UA's Department of Entomology and also is a member of the UA's BIO5 Institute. “This stunning success came from decades of teamwork, with effective collaboration among growers, biotech companies, the USDA, the Arizona Department of Agriculture, and University of Arizona Extension and research scientists.”
UA conducted early testing on cotton genetically engineered to control pink bollworm, called Bt cotton, which produces caterpillar-killing proteins from the bacterium Bacillus thuringiensis. The Bt proteins are not toxic to people or wildlife.
Entomology specialist Peter Ellsworth was involved with early testing on Bt cotton, and led the development of integrated pest management (IPM) programs for cotton. Cotton growers have not had to spray for pink bollworm since 2008, which together with IPM has saved them over $20 million per year while increasing safety for growers and environmental quality for all people of Arizona.
Since 1996, UA scientists have led a resistance management program for pink bollworm that has been essential in suppressing the pest and stopping it from developing resistance to Bt cotton in Arizona. Tabashnik led groundbreaking work in establishing the “refuge strategy,” the primary approach now used worldwide to delay adaptation of insect pests to genetically engineered crops.
A UA-USDA team of entomologists recently won a USDA grant to support pink bollworm research in Arizona for 2018-2021. This ongoing work is conducted under secure containment that prevents the pest from escaping into the environment. The continuing research aims to better understand resistance to Bt cotton that has evolved in other parts of the world, including India, so if the pest is re-introduced to Arizona the tools will be in place to defeat it again.