The Buzz On Mosquitoes

Mosquito control experts and human health authorities are concerned that Americans are becoming complacent about protecting themselves and their horses against West Nile virus (WNV). They discussed this trend and new mosquito control techniques to prevent the spread of mosquito-borne illnesses at the Centers for Disease Control and Prevention's (CDC) West Nile virus meeting held Feb. 23-24 in San Francisco, Calif., and the American Mosquito Control Association (AMCA) convention meeting held Feb. 23-March 2 in Detroit, Mich.

According to Lyle Petersen, MD, MPH, director of the CDC's Division of Vector-Borne Infectious Disease, who spoke at the AMCA meeting, WNV often goes unreported. He says the persistence of the virus in the United States since its emergence in 1999 tells us it's not fading.

Fighting Back

Alan Barrett, PhD, vice chair for research and professor in the Department of Pathology's Center for Tropical Diseases at the University of Texas Medical Branch, presented research at the CDC meeting. He and his colleagues have observed that when two specific, naturally occurring mutations in the genetic makeup of WNV (referred to as NS4B and NS5) occur simultaneously, the virus becomes dramatically less harmful. Scientists think that being able to pick apart the gene and understand why this combination of mutations weakens the virus might help them disrupt the virus' function with drugs or a vaccine.

Another group of scientists presented information on the use of sound waves in areas of standing water to kill mosquito larvae. Joe Conlon, AMCA technical advisor, said it's a promising technology that kills the larvae by using sound energy to destroy air bladders the larvae use to float rather than relying on chemicals. The device costs between $5,000 and $10,000, a feasible price for municipalities, but probably not the most cost-effective solution for individuals or farms. Conlon says horse owners' best defense against WNV--vaccination of their horses in combination with mosquito reduction techniques--is a more practical and affordable route.

Conlon encourages owners to rid their barn areas of standing water, drain and clean water troughs several times a month to fend off breeding and developing mosquitoes, and cut vegetation around pond edges.

He also recommends using a "wettable powder" formulation instead of an emulsifiable concentrate liquid spray when applying insecticide sprays to surfaces where mosquitoes may rest, such as stable walls.
Liquid sprays can be absorbed by porous surfaces like wood and concrete, diminishing their effectiveness. Wettable powders dry on the surface, leaving a residue that is lethal to mosquitoes.

About the Author

Amanda Borozinski

Amanda Borozinski is a former features writer and photographer for the Keene Sentinel Newspaper. A mother,and a full-time horse enthusiast, Amanda is now a full-time photographer, specializing in weddings, seniors, mommy-to-be, engagements and anything else that interests her. More information can be found on her website, Stay on top of the most recent Horse Health news with FREE weekly newsletters from Learn More