It took more than 20 years, but a device invented by Army entomologists to control the population of mosquitoes that carry diseases is now available to installations.
As well, the device is commercially available to Soldiers and civilians for home use and to target day-biting mosquitoes that attack during picnics and outings.
"The primary targets of the device, called a lethal ovitrap, are female Aedes aegypti and Aedes albopictus mosquitoes that can be found throughout the Eastern and Southern U.S., South America, and other parts of the world," explained Thomas Burroughs, U.S. Army Public Health Command Entomological Sciences Program manager.
"These mosquitoes are carriers of dengue fever, West Nile virus, yellow fever and chickungunya virus," said Burroughs. "A method of controlling vectors of these diseases has been sought by the military for many years."
The trap works by exploiting the female mosquito's biological need to lay eggs.
"The traps contain a pesticide that kills both larvae and the adult female, thus preventing her from laying more eggs in other locations," according to Sheila Adams, Entomological Sciences Program laboratory technician.
When first designed, the traps were used to monitor the type and number of mosquitoes in an area.
In the 1990s, Brian Zeichner from what was then the U.S. Army Center for Health Promotion and Preventive Medicine and is now the USAPHC and Michael Perich of the Walter Reed Army Institute of Research developed this breeding container. Ultimately, they enhanced its capabilities and made it lethal to the insects and their larvae. The USAPHC and WRAIR hold the patent on the device they developed.
"These dark, water-filled containers mimic the natural breeding site of container-breeding mosquitoes," said Burroughs. "Both the Aedes aegypti and Aedes albopictus mosquitoes prefer to lay their eggs in small, man-made containers that hold standing water, including rain buckets, flower pots and old tires."
Once the female goes into the trap, she and any hatchlings are history.
The lethal ovitraps have been used in many field studies to show their effectiveness in reducing mosquito populations and thus lowering the risk of disease transmission, according to Burroughs.
"In January the trap received an Environmental Protection Agency registration number," he said. "Pesticide products sold in the U.S must have this registration."
The Armed Forces Pest Management Board approved the USAPHC's lethal ovitrap for National Stock Number assignment. It is available through the federal supply system, and USAPHC environmental experts are encouraging installations and public health staffs to use it.
"Military installations can integrate this lethal ovitrap into their mosquito control programs. This will give them an effective tool that also reduces pesticide exposures to applicators, residents and the environment," said Lt. Col. Gayle McCowin, Environmental Health Engineering Portfolio director at the USAPHC.
But the military is not the only user of mosquito and egg-killing egg- or larvae-killing traps.
The World Health Organization advises the use of this type of trap in its report on controlling dengue fever. "Studies have shown that (mosquito) population densities can be reduced with sufficiently large numbers of frequently-serviced traps. Life expectancy of the vector may also potentially be shortened, thus reducing the number of vectors that become infective," the report states.
The good news is that these lethal ovitraps are now available in local retail stores for civilian use as well as for military preventive medicine and medical personnel. The lethal ovitrap may be ordered through the military supply system using the NSN 6840016284751 or by the item name "insecticide, dichlorvos."
"This is a good news story for everyone," said McCowin. "These traps will have a significant impact in reducing mosquito-borne illnesses around the world. They are an important tool in the inventory of Department of Defense pest control products."