Timing is Everything When Controlling Insects

Comedians might be born with good timing, but stored product warehouse managers can rely on ARS research to help them time insecticide applications to control insect pests.

Most U.S. warehouses fumigate three to four times a year to control moths and other stored product pests. Costly fumigation--averaging about $20,000 each time--begins even when only two or three moths are sighted in the warehouse.

Better timing of insecticide applications can be made with an accurate count of insects present and their development stages, according to ARS researchers.

ARS entomologists James E. Throne and David W. Hagstrum at the U.S. Grain Marketing Production and Research Center in Manhattan, Kan., developed a computer model to track the development of the almond moth, a worldwide pest of stored grain and other products.

The predictions from their model can help warehouse managers decide when to use alternatives to insecticides. For example, cooler temperatures can reduce or stop moth reproduction and slow further development of immature moths. The entomologists know that insects are cold-blooded and thrive at warmer temperatures. Only a slight temperature drop--from 75 to 65 degrees F-- could curtail moth activity. So, turning on the fans to cool the warehouse is less expensive and environmentally safer than fumigating.

An article about the model and future "clones" of it appears in the July issue of Agricultural Research magazine. The article is also on the World Wide Web at:

http://www.ars.usda.gov/is/AR/archive/jul98/pest0798.htm

Scientific contacts: James E. Throne and David W. Hagstrum, ARS-USDA, U.S. Grain Marketing Production and Research Center, Manhattan, KS. To reach Throne: (785) 776-2796, throne@usgmrl.ksu.edu; or Hagstrum (785) 776-2718, hagstrum@usgmrl.ksu.edu, fax (785) 776- 2792.