Using pests as part of an insect birth control program helps to get rid of them, UA researchers find. A new approach that combines the planting of pest-resistant cotton and releasing large numbers of sterile moths has virtually eliminated of the world's most destructive cotton pests from Arizona.
The novel control strategy, published in the Nov. 7 advance online publication of the journal Nature Biotechnology, has allowed growers to maintain high cotton yields without spraying insecticides to control pink bollworm.
"We are running the pesticide treadmill in reverse," said Bruce Tabashnik, department head of entomology in the UA's College of Agriculture and Life Sciences. "Our new approach has resulted in huge environmental gains. We are using cutting-edge technology to create sustainable cotton farming practices."
The new approach is part of a multi-pronged team effort to eradicate pink bollworm from the southwestern US and Mexico, in which Tabashnik and his coauthors play a leading role.
Caterpillars of the pink bollworm (Pectinophora gossypiella) are one of the most detrimental pests to cotton production worldwide. First detected in the US in 1917, this invasive insect species wreaked havoc on Arizona's cotton growing industry, with larvae infesting as many as every other cotton boll (the fruit capsule containing the precious threads).
A breakthrough came in 1996 with the introduction of Bt cotton, a genetically engineered crop containing a gene transferred from the bacterium, Bacillus thuringensis, endowing the plants with a protein that kills some, but not all insects. Unlike typical broad-spectrum insecticides, which kill most insects, pests or not, the Bt toxin only targets certain insect species. Pink bollworm caterpillars munching on Bt cotton die before becoming adults and therefore do not reproduce.
Bt crops have allowed farmers to cut back on spraying, but, much like antibiotics,
|Contact: Daniel Stolte|
University of Arizona