ARS | Publication request: Residual mosquito barrier treatments on U.S. military camouflage netting in a southern California desert environment

Submitted to: Military Medicine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 1, 2010
Publication Date: August 1, 2010
Citation: Britch, S.C., Linthicum, K., Wynn, W.W., Walker, T.W., Farooq, M., Smith, V.L., Robinson, C.A., Lothrop, B.B., Snelling, M., Gutierrez, A., Lothrop, H.D. 2010. Residual mosquito barrier treatments on U.S. military camouflage netting in a southern California desert environment. Military Medicine. 175(8):599-606.

Interpretive Summary: One way to reduce the number of mosquitoes entering an area is to surround the area to be protected with a perimeter of insecticide. This insecticide must be a product designed to dry out and persist and still be toxic after being sprayed, termed “residual insecticide”, such as the synthetic pyrethroid bifenthrin. The most common type of perimeter treatment is to spray existing vegetation around the protected area, treating perimeters of vegetation with residual insecticides for protection from mosquito vectors has potential for U.S. military force health protection. However, for current U.S. military operations in hot-arid environments with little or no vegetation, residual applications on portable artificial materials may be a viable alternative. Artificial materials such as desert camouflage netting are already organic to many deployed military units, and we investigated whether these materials could function as a mosquito-reducing perimeter after treatment with residual insecticide. We evaluated bifenthrin residual treatments of U.S. military camouflage netting under hot-arid field conditions in a desert area in southern California exposed to abundant wild Culex tarsalis mosquitoes. We assessed the ability of the treatment to reduce the numbers of mosquitoes penetrating perimeters of netting and reaching CO2-baited mosquito traps. These traps simulated the presence of a human host attractive to biting female mosquitoes. We found that treated camouflage netting barriers reduced mosquitoes by =50% for 7-14 days and by 20-35% for 21-28 days compared to untreated barriers. Although these reductions of mosquitoes may be translated into reductions in risk of exposure to mosquito-borne diseases, we emphasize that barrier treatments should be a component in a suite of insect control measures to be effective. This suite should include the use of personally worn repellents and treated clothing, as well as reduction of mosquito breeding areas.

Technical Abstract: Treating perimeters of vegetation with residual insecticides for protection from mosquito vectors has potential for U.S. military force health protection. However, for current U.S. military operations in hot-arid environments with little or no vegetation, residual applications on portable artificial materials may be a viable alternative. We evaluated bifenthrin residual treatments of U.S. military camouflage netting under hot-arid field conditions in a desert area in southern California exposed to abundant wild Culex tarsalis mosquitoes. We assessed the ability of the treatment to reduce the numbers of mosquitoes penetrating perimeters of netting and reaching CO2-baited mosquito traps. Treated camouflage netting barriers reduced mosquitoes by =50% for 7-14 days and by 20-35% for 21-28 days compared to untreated barriers. Although reductions may be translated into reductions in risk of exposure to mosquito-borne diseases, we emphasize that barrier treatments should be a component in a suite of insect control measures to be effective.