Southwest farmers could face a new insect pest, the Old World bollworm, which poses a more serious threat than the more familiar New World bollworm.
The pest attacks more crops than does its close relative, the New World bollworm, known as the cotton bollworm or the corn earworm. Some strains have shown some resistance to the Bt toxins in transgenic crops but scientists say the invading may still be controlled by this technology.
The pest, Helicoverpa armigera, was recently detected in Florida, the first time it has been identified in the continental United States. It was discovered in Brazil in 2013.
“Our cotton bollworm, Helicoverpa zea, has been a pest of cotton and other crops in North America for as long as crops have been grown here,” said Dr. Charles Allen, Texas A&M AgriLife Extension Service state integrated pest management leader in San Angelo.
“The New World bollworm and the Old World bollworm both have larval stages that become moths as adults, are very closely related and do similar damage to crops,” Allen said. “But the Old World variety can attack an even broader range of plants, 180 kinds of plants that we know of as opposed to our bollworm, which eats fewer cultivated and wild host plants.
“Ours is susceptible to most insecticides and transgenic crops, but a key difference is that this invading cousin has become resistant to many classes of insecticides. Some strains in the Old World have even become resistant to the Bt toxins in transgenic crops, but to the best of our knowledge, the invading strain can still be controlled by this technology.”
Dr. Pat Porter, AgriLife Extension entomologist at Lubbock, said Texas crops that might eventually be affected include cotton, corn, sorghum, citrus, wheat and a variety of vegetables and other specialty crops.
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“We don’t know when or even if the Old World bollworm will arrive in Texas, but AgriLife Extension, Texas A&M AgriLife Research and the Texas A&M department of entomology are pre-emptively assembling a team of state, national and international experts to monitor the possible arrival of the insect in the southern U.S.,” Porter said.