What is in this article?:
- Battling bollworm a cotton world away
- Increased insecticides
- China first introduced Bt cotton in 1997. For the first decade, Bt cotton was highly effective against both cotton bollworm and pink bollworm in China.
- Early signs of resistance to Bt cotton have been detected in caterpillars collected from Chinese fields.
University of Arizona entomologists are joining forces with scientists on the other side of the globe to protect cotton in China from potentially devastating insect pests.
Xianchun Li, associate professor of entomology in the UA College of Agriculture and Life Sciences, and Bruce Tabashnik, head of the department of entomology, are partnering with Chinese scientists to combat insect resistance to genetically engineered cotton plants.
Li, Tabashnik and Kongming Wu, a top researcher with the Institute of Plant Protection at the Chinese Academy of Agricultural Sciences in Beijing, have obtained a grant from China’s National Science Foundation of 2.95 million Chinese yuan – equivalent to $475,000 U.S. dollars – to study resistance in pink bollworm in China and to develop strategies against it.
Farmers have struggled for longer than a century to keep two insect pests – cotton bollworm and pink bollworm – from destroying their cotton crops. In Arizona, where cotton has long been a key industry, growers once battled the pink bollworm and its insatiable appetite for cotton by spraying insecticides. But such sprays are bad for the planet and become powerless when the pests evolve resistance.
A significant new weapon in the battle against bollworms arrived in 1996. Growers in the U.S. began planting genetically engineered cotton that produces an insecticidal protein derived from the widespread bacterium called Bacillus thuringiensis – or Bt.
The Bt toxin made by genetically engineered cotton is safe for humans and other non-target organisms but deadly to the caterpillars of pink bollworm and cotton bollworm.
The key to sustaining the success of Bt cotton is delaying evolution of resistance to the Bt toxin in pests. Researchers from the UA College of Agriculture and Life Sciences have played a critical role in developing strategies to achieve this goal. That effort has succeeded brilliantly according to Tabashnik, with cotton farms in Arizona serving as a model for thwarting pest resistance.
"Arizona is the poster child for successful resistance management for a Bt crop," Tabashnik said. "Pink bollworm is rare now in Arizona. We have very strong evidence that there is no resistance in the field."
The College of Agriculture and Life Sciences has collaborated with growers, biotechnology companies, the U.S. Department of Agriculture and the U.S. Environmental Protection Agency to manage resistance and eliminate insecticide sprays against pink bollworm in Arizona.