Read: more about the research in Agricultural Research magazine.

Minus-Ceralure: Better Baiting for the Medfly

BELTSVILLE, Md., Oct. 23--Scientists with the U.S. Department of Agriculture’s Agricultural Research Service are pleased with early results of a new attractant for the Mediterranean fruit fly, one of the most serious agricultural pests worldwide.

The new attractant captures more hapless male fruit flies--an asset that would make medfly monitoring programs more foolproof. It was developed by former ARS chemist Andre Raw in Beltsville, Md., and entomologist Eric B. Jang in Hilo, Hawaii.

Nicknamed “minus-ceralure,” the attractant stays potent in traps about three to four times longer than trimedlure, the most widely used commercial attractant, said Jang.

More importantly, “minus-ceralure is about four to nine times more attractive to medflies,” said Jang. He coordinates field testing from the agency’s laboratory in Hawaii, where the medfly is established.

“Minus-ceralure ranks as the best medfly attractant yet reported,” said ARS Administrator Floyd Horn, noting that its parent compound--ceralure--was also developed by ARS scientists in Beltsville and Hilo in 1988. “With help from today’s improved technology, Dr. Raw was able to extract the most active compounds in ceralure and purify a large enough quantity to test on the insects.”

Threat of medflies invading the U.S. mainland musters hundreds of state and federal agents to annually deploy some 150,000 traps baited with trimedlure. If some medflies should sneak into the country and wind up in a trap, thousands more traps are deployed to help keep the six-legged pests confined to an area where they can be snuffed out.

With minus-ceralure, “it’s more likely the first invaders would be captured before the infestation could become established,” said Raw. And the attractant is powerful enough that it could potentially be used for mass-trapping to eradicate the flies. Traps baited with an attractant such as minus-ceralure “are more environmentally sound than spraying insecticides and may be less expensive than releasing sterile-male medflies,” Raw added.

Jang’s tests are aimed at finding the least amount of chemical that can be used for the longest-lasting trap. "Cost-effectiveness is particularly important with minus-ceralure because--for now, anyway--it costs significantly more to produce than trimedlure," Jang said.

ARS has applied for a U.S. patent on the new attractant, formally known as minus-ceralure B1. The agency is seeking a cooperative agreement with industry to develop a more efficient synthesis for larger-scale testing and, ultimately, for commercial production of the attractant.

In relatively quiet years, more than a million trimedlure dispensers are sold in the United States alone to keep the monitoring traps effective. The medfly is also a major agricultural pest in Europe, Africa, Australia, Pacific areas, and in Central and South America.

A story about the research appears in the October issue of Agricultural Research magazine.

Scientific contact: Eric B. Jang, ARS U.S. Pacific Basin Agricultural Research Center, Hilo, Hawaii, phone (808) 959-4340, fax (808) 959-4323, ejang@pbarc.ars.usda.gov.