Controlling mosquitoes to reduce risk of diseases like West Nile virus is largely a backyard effort, said Max Meisch, University of Arkansas entomologist. “Community abatement programs alone won't solve the problem,” Meisch said. “The primary battleground for West Nile virus is the backyard.”
Meisch has helped develop and implement effective mosquito abatement programs for rice-growing areas through his Arkansas Agricultural Experiment Station research in mosquito bionomics and control using non-chemical approaches and conventional methods. “My goal has been to optimize non-chemical control and judicious use of chemicals,” he said.
The spread of West Nile virus has moved mosquito control higher on priority lists for many areas of the state.
One human case of West Nile virus has been reported in South Carolina this year, and two horses have died in Arkansas from the disease. Meisch said the virus is believed to be spread across the country by birds and transferred to humans or other hosts by mosquitoes.
Meisch said three mosquito species proven to carry West Nile virus are found in Arkansas. The number one carrier, the Southern house mosquito, is a common backyard pest that breeds in standing, polluted water, bites primarily at night and is limited to a short flight range.
“The best way to eliminate this pest is to clean up your own yard,” he said. “Clean out your gutters, don't let rainwater collect in old tires or other containers and change the water often in pet bowls and bird baths.”
Although West Nile virus is getting most of the attention lately, Meisch said mosquitoes transmit many diseases, some of which are more dangerous.
“West Nile pales compared to mosquito-borne malaria, the number one killer of children under five in the world,” he said. “Depending on which report you believe, there are 500 million to 700 million cases of malaria worldwide responsible for 100 million to 200 million deaths.”
Meisch said malaria, once a problem in Arkansas, has been abated by anti-malarial drugs and residual house spraying. But the mosquito species that transmitted the disease are still found in the state.
St. Louis encephalitis and Eastern equine encephalitis have also occurred in Arkansas. St. Louis encephalitis is closely related to West Nile virus and caused illness in people living in and around Pine Bluff, Ark., in 1992. Eastern equine encephalitis has occurred only in horses and emus in Arkansas.
The Asian tiger mosquito, a relative newcomer to the state, is a known transmitter of Dengue fever, Meisch said. Dengue fever can cause deadly hemorrhagic fever and has occurred as far north as the Rio Grande valley on the Mexico-Texas border. The Asian tiger mosquito has been in Arkansas at least 10 years. “The potential exists for this disease to spread here,” he said.
Mosquito-transmitted diseases threaten pets as well as humans. “Dog-owners should use heart worm protection and horses are probably more susceptible to West Nile virus than humans,” he said.
“Organized abatement is the best means of controlling mosquitoes,” he said. “It's simple in concept, but can be complex and expensive to set up and operate.”
Fred Miller is science editor for the Arkansas Agricultural Experiment Station.