Minus-Ceralure: Better Baiting
for the Medfly
By Judy McBride
October 23, 2000
BELTSVILLE, Md., Oct.
23--Scientists with the U.S. Department of
Agricultures 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
agencys 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 todays 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, its 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
Jangs 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,