Old World bollworm, a new and potentially devastating insect pest of U.S. cotton and other crops, has been identified in Florida. It was discovered in Brazil in 2013, in Puerto Rico in 2014, and a few individuals were identified in Florida earlier this year.
“This is a severe economic pest in most places where it is established,” says Greg Sword, Texas A&M AgriLife Extension entomologist, who discussed the possibility of it becoming a significant pest in cotton, soybeans, wheat, small grains, and other U.S. crops during the cotton segment of the Texas Plant Protection Association’s 27th annual conference in Bryan, Texas.
“The Old World bollworm is one of the world’s most destructive agricultural pests,” he says. “It is the target of more than 75 percent of all insecticides applied in India and China.”
Managing the pest could be complicated, Sword says, since the Old World bollworm has “known markers for pyrethroids resistance.” It also hybridizes easily with the bollworm U.S. farmers are already familiar with, and the two are difficult to differentiate. “We can’t tell the females of the two species apart,” he says, “and we have to dissect males to differentiate them. We could be looking at a genome invasion instead of an invasive species.”
It is a widely adaptable pest, feeding on more than 200 different plant species, and could be adaptable across more than half of the United States. Sword says the few Old World bollworm specimens found in Florida “failed to establish,” but wonders if hybridization may have already occurred.
Not just cotton's problem
He thinks the pest is coming, and that positive identification will test integrated pest management techniques. “We may have to monitor at the genome level,” he says. “Genetic testing is costly. But the risks and costs are not specific to cotton — this is everyone’s problem.”
Research funding is scarce, however, since the pest is one that may or may not invade U.S. crops. “Personnel, products, and logistics are lacking for a major response,” Sword says. Preparation includes monitoring. “APHIS is involved, and does have a regulatory response system in place.”
He doesn’t expect much advance warning. “Problems are likely to just show up — and we do risk a significant increase in insecticide use.”
Biocontrol may be one control option, he says. “Also, we hope to slow the spread in Central and South America. We hope to learn from our neighbors: How have they controlled Old World bollworm?”
Sword says preparation also include screening the efficacy of major IPM tools, Bt varieties, biological controls, cultural practices, and available insecticides.
It’s not panic time, he says. “Plenty of people in other parts of the world grow crops successfully in the presence of this pest.”
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