Researchers demonstrate improved appeal of sterile flies that save crops

February 27th, 2014 by Mickie Anderson in Biology / Plants & Animals



What sterile-insect operations need, says University of Florida insect physiologist Daniel Hahn, is the insect world's version of George Clooney: 52 years old, gray-haired and still dazzling the ladies.


"Our males (insects) are not only more sexually competitive, they are maintaining their sexual competitiveness and their virility, into old age," Hahn said, "and that has the potential to make them much better biological control agents."


A female duped into accepting a sterile male would then find herself without offspring, thus trimming the population and its threat to the state's important agricultural crops. The technique has been used effectively against the Mediterranean fruit fly, called the Medfly, and the cattle-infesting screw-worm fly, among others.


The "low-oxygen effect" has been known for decades, but the physiological basis for it had never been rigorously tested or analyzed, Hahn said. They suspected, and found, that under the low-oxygen conditions, the insects' cells would produce antioxidants that can help better protect them from the off-target radiation damage.

Some operations that rear and sterilize insects, such as one in Guatemala that produces many of the sterile medflies dropped over Florida's major ports roughly every seven days, do employ low-oxygen conditions, called hypoxia or anoxia. But many others don't, he said, including those who rear and sterilize the cactus moth.

The reseachers found using a low-oxygen environment during sterilization boosted the sterile males' longevity as well as their ability to attract and successfully mate. They found that the positive effects of low-oxygen treatments even extended into their 'old age' – in the insects' case, about 30 days under cushy laboratory conditions.


The January paper was published by PLoS One, and the February paper in the Journal of Economic Entomology. Hahn and López-Martínez were joined as authors of that paper by James Carpenter of the USDA's Agricultural Research Service in Tifton, Ga., and Stephen Hight of the USDA-ARS at Florida A&M University in Tallahassee.

Provided by University of Florida

"Researchers demonstrate improved appeal of sterile flies that save crops." February 27th, 2014. http://phys.org/news/2014-02-appeal-sterile-flies-crops.html