New Kit to Identify Tissue-Invading Fly
Maggots By Jan
January 16, 2001
Screwworm flies, trying to sneak back into the United States,
can be identified using a new diagnostic field kit developed by
Agricultural Research Service
Using the kit reduces, from several days to a few hours, the
time it takes to differentiate screwworm fly maggots from similar fly species
and take action to contain them, according to Steve Skoda, a screwworm
researcher at ARS
Livestock Insects Research Unit, Lincoln, Neb.
Skodas lab developed the kit to support the
Animal and Plant Health Inspection
Service (APHIS), which coordinates current screwworm eradication programs
in Central America. Agdia, Inc., of
Elkhart, Ind., is collaborating with ARS to commercialize the technology. Both
ARS and APHIS are agencies of the U.S.
Department of Agriculture.
Screwworms can harm or kill livestock, pets and people by
feeding on living tissue at open wounds. Eradication programs have eliminated
the parasite from the U.S., Mexico and most of Central America. Trade and
travel to and from screwworm-infested regions like South America make
re-infestations a concern.
APHIS protocols for containing U.S. outbreaks involve the
sterile insect technique (SIT). This approach calls for releasing sterilized
male screwworm flies to mate with females in the wild. No eggs hatch, so the
wild population collapses. In cases where only a few screwworms are detected,
such as on imported cattle, insecticides and quarantine procedures may be used.
With the new test kit in hand, a veterinary officer could
confirm a suspected screwworms identity in six hours rather than ship it
to a lab for visual examination. The kit, 99.9% accurate, turns blue when a
specimen is a screwworm.
Speed and accuracy are critical to choosing and applying the
appropriate responses to suspected outbreaks. This includes coordinating costly
sterile fly releases. The kits accuracy hinges on a monoclonal antibody
that binds with a protein antigen in screwworm tissue samples. Skodas lab
and University of Nebraska
graduate James Lester Figarola discovered the protein.
A commercial test kit could be available within two years,
according to Agdia.
Scientific contacts: Steven R. Skoda, ARS
Livestock Insects Research Unit, Lincoln, Neb., phone (402) 437-5267, fax
(402) 437-5260, firstname.lastname@example.org. Willye W.
Bryan, Insect Diagnostics Manager, Agdia, Inc., Elkhart, Ind., phone (219)
264-2014, fax (219) 264-2153, email@example.com.