- A new mosquito larvicide developed at the University
of Florida's Medical Entomology Laboratory in Vero Beach is expected to
be on the market under the brand name "Skeetercide" in time
for the next mosquito season. The "Skeetercide" formulation is
based on a naturally occurring mosquito hormone--"trypsin modulating
oostatic factor" or TMOF--that is produced in mosquito ovaries and
acts to control digestion of the blood ingested when a mosquito bites.
When ingested by larvae as part of a mosquito control program, TMOF switches
off the digestive system, effectively starving the larvae to death in 4-6
days.
-
- After discovering the biological properties (the mode
of action) of the active ingredient, the research team led by biochemist
Dov Borovsky needed to develop a formulation that would be readily eaten
by larvae and that would remain near the water surfaces where mosquito
larvae eat. They found that yeast serve well for this purpose when bioengineered
to include TMOF and bound with cellulose particles to produce granules
that are stable in the water for about 20 days.
-
- In lab tests, the hormone has been shown to kill all
mosquito species tested and to be effective in salt and fresh water. The
next step in determining efficacy is field testing, which will begin this
month in salt ponds in Key West, Florida. TMOF is expected to be environmentally
benign, since mosquito predators ingest it regularly with no evidence of
side effects. Product developers say it poses no human health concerns
and that it is "safe enough to use in drinking water containers."
The product is being commercialized by a North Carolina company, Insect
Biotechnology Inc., that holds the license to U Florida patents.
-
- Although the other commonly used mosquito larvicides
are also classified by EPA as "reduced risk" pesticides, the
development of TMOF is exciting news because the availability of alternatives
is an important pest control strategy both for (a) staving off development
of insect resistance resulting from exclusive and repeated use of any one
product or method and (b) having products suitable for disparate conditions.
For example, Culex pipiens and C. quincquefasciatus (the Northern and
Southern House Mosquito species, respectively) tend to breed in polluted
water where the larvicide Bacillus thuringiensis israelensis (Bti) is less
effective.
-
- (Source of information about TMOF: "Mosquito diet
pill seen as West Nile weapon, Jane Sutton, Environmental News Service,
Tuesday, September 03, 2002. Copyright 2002 - Reuters. Full text http://enn.com/news/wire-stories/2002/09/09032002/reu_48319.asp.)
-
- ___
-
- Lois Levitan, PhD Program Leader
- Environmental Risk Analysis Program
- Center for the Environment
- 213 Rice Hall, Cornell University
- Ithaca, New York USA 14853-5601
-
- Phone: (607) 255-4765 Fax: (607) 255-0238
- Email: LCL3@cornell.edu
-
- Program Email: envrisk@cornell.edu
- Web:http://www.cfe.cornell.edu/ERAP
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