An Improved Diet Helps Screwworm Control Efforts
March 15, 2007
A refined diet for screwworms that has
been developed by Agricultural Research Service (ARS) scientists will help ensure that an
ample supply of sterile screwworm flies can be produced to continue efforts to
eradicate this pest.
For over 50 years, ARS scientists have provided leadership in intensive
interagency efforts directed toward eradicating screwworms--first from the
United States, in 1982, and then from Mexico, in 1991. Leading the way today
F.B. Chaudhury, in the
Screwworm Research Unit's fly-rearing factory at Tuxtla Gutierrez, Chiapas,
Skoda, research leader of the unit's central office in Panama City, Panama.
The larvae that hatch from screwworm eggs cause great damage to livestock,
wildlife and other warm-blooded animals as they burrow into and feed on their
The key to eradication has been the mass-rearing of trillions of screwworm
flies (Cochliomyia hominivorax). Once reared, young males are made
sexually sterile and then air-shipped to other facilities for release in
support of screwworm control programs that extend to Central America. Mating
between native females and sterilized males produces no offspring, eventually
leading to the pest's disappearance.
By conducting basic and applied research, ARS supports the
Animal and Plant Health Inspection
Service, the U.S. Department of Agriculture (USDA) agency in charge of ongoing screwworm
For example, a new egg powder and molasses diet developed by Chaudhury for
adult flies replaces the smelly, costly horsemeat-and-honey diet first used in
the 1950s. The new diet is also easier to handle and more cost-effective. By
replacing shredded recycled paper or a gelling agent with cellulose fiber to
solidify and provide texture for the larval diet, the screwworm-release program
can save $100,000 or more annually.
Skoda is working closely with the United States-Panama Commission for the
Eradication and Prevention of Screwworms, which recently built a $40-million
research facility in Panama City.
more about the research in the March 2007 issue of Agricultural
ARS is the USDA's chief scientific research agency.