Pink bollworms have been a longstanding nightmare for western cotton farmers.
The insects lay eggs in cotton bolls and when the larvae hatch they burrow through the lint, to feed on seeds. This damages both fiber and seed oil. With high humidity, it only takes one or two larvae to destroy an entire boll because damaged bolls are vulnerable to infection by boll rot fungi, according to the University of California at Davis.
The National Cotton Council estimates that pink bollworms costs US cotton producers more than $32 million each year in control costs and yield losses.
The United States Department of Agriculture has long used an ingenious program, called sterile insect technique, to stem pink bollworm infestations.
Pink bollworms are raised, fed a diet of red dye, giving them a permanent, unnatural color, blasted with radiation to make them sterile and released near infestations of cotton-eating pink bollworms.
The sterile bollworms mate with the fertile pink bollworms, which fools the latter into a false state of pregnancy. As a result, an entire generation of bollworms die off without reproducing.
The program, begun in California’s San Joaquin Valley in the mid-1960s, originally relied on the use of small aircraft to distribute irradiated pink bollworms. Now a pilot program has them being fired from cannon attached to drones onto cotton fields.
“Drones are a cheaper delivery method than the manual throw-moths-out-of-a-small airplane method that has been used in the past, so if the tests continue to go well, you might be seeing more moths flying out of drones in the future,” according to Popular Science.
Pink bollworms are found in West Texas, New Mexico, Arizona, California and northern Mexico.
Sterile moths are raised and irradiated at the Pink Bollworm Rearing Facility in Phoenix, Ariz., then shipped to Shafter, Calif., for aerial release in the San Joaquin Valley, where more than 90 percent of California’s cotton is grown.
One of the great benefits of the program is that it doesn’t use pesticides, benefiting the environment.