Mosquito research in the press
Stelenes at aol.com
Stelenes at aol.com
Tue Feb 22 11:05:55 EST 2000
With all the talk of mosquitos, I thought this article from the Internet
newswires would be of interest:
Why Do Mosquitoes Love People?
AM ET February 22, 2000
WASHINGTON (AP) - Whether it's a summer evening stroll, a fishing trip or
a picnic in the park, more than likely
those whiny little devils - mosquitoes - are going to find you.
Agriculture Department scientists are trying to learn why.
Humans give off hundreds, maybe thousands, of natural scents that bugs
"So far, we have found more than 340 different chemical scents produced by
human skin, and some of these attract
mosquitoes," says Ulrich R. Bernier, a chemist with USDA's Agricultural
"Scientists have known for years that lactic acid present on human skin is
a mosquito attractant. So far, this is true for
only a handful of species, one of which is the yellowfever mosquito, Aedes
aegypti. Finding what attracts mosquitoes
will ultimately help us find ways to control them," Bernier says in the
February issue of Agricultural Research magazine.
Bernier works at the ARS Center for Medical, Agricultural,and Veterinary
Entomology's Mosquito and Fly Research
Unit in Gainesville, Fla. There, he and his colleagues are testing
individual scents and combinations for attractiveness to
different mosquito species.
Mosquitoes are placed in one side of a cage divided by a screen. An
attractant is pumped in to see if mosquitoes will
come to the screen.
Bernier says it's difficult to find an attractant because it appears that
multiple compounds are needed to attract
Since 1997, Bernier has been combining different blends and screening them
at different levels to see which blends
draw mosquitoes best. A promising scent is later combined and tested in a
With some blends, he says, "We can get about 90 percent of the mosquitoes
in the cage to come to the mixture. This
is impressive considering my own arm and hand attract only about 70
percent of them."
"We still don't have a perfect blend," Bernier notes. "But, we're a lot
closer than we've ever been." Several promising
blends, for which Bernier has filed a patent, are combinations of
human-produced odors with and without lactic acid.
In 1968, Gainesville scientists discovered lactic acid is an attractant
for the yellowfever mosquito. At that time, carbon
dioxide (CO2) was also thought to be necessary to attract mosquitoes.
Bernier says what might be the single most
important discovery about these blends is they don't use CO2, unlike most
other blends or attractants. All of the
specific chemical combinations he's isolated for both the yellowfever
mosquito and Anopheles albimanus, a tropical
mosquito that spreads malaria, don't need the CO2.
ARS entomologist Daniel L. Kline found something else: mosquitoes love
"I wore the socks for 12 hours on three consecutive days. When I wasn't
wearing the socks, I put them in a sealed
plastic bag," Kline says. "I also found mosquitoes love Limburger cheese.
Interestingly enough, the main ingredient in
the cheese is a bacterium that can be found on the human foot."
Donald R. Barnard, leader of the Gainesville research unit, says, "We
expect attractant-enhanced traps to eventually
surpass pesticides in effectiveness. We hope to develop stand-alone traps
that can be used by homeowners or
"One day we hope to develop systemic repellents that can be taken orally
or devices that can be worn to neutralize
the attractive effects of a person to a mosquito," he adds
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