West Umatilla Mosquito Control District

testing mosquito surveillanceCollecting adult mosquitoes can provide several important pieces of information. When traps are set at specific locations over a period of time, or in response to service requests, increases in the mosquito population can be detected. Once these mosquitoes are identified, control measures can then be more easily directed. Knowing what species of mosquito is breeding can help Vector Control Technicians find the breeding source and take the appropriate control measures. After identification by District Staff, these mosquitoes can also be tested for the presence of disease. The detection of virus in a mosquito which feeds on humans indicates a true potential for human disease, and immediate control measures can be implemented. Trap collections not only determine where control measures are needed, but also determine the effectiveness of control measures which are in place.

CDC-type trap

CDC-Type CO2-Baited Trap

This trap is used to selectively sample host-seeking females attracted to the trap by the sublimation of dry ice into carbon dioxide (CO2) which simulates the exhaled respiratory gases of birds or mammals. The trap consists of a central 3" diameter plastic cylinder housing a 6V DC motor and a 4" fan blade, a collection net attached to the bottom of the cylinder, a 6V battery power source, and an insulated container with 2-5 pounds of dry ice. CDC-type traps utilized by the District also incorporate a mini-light source which help attract mosquitoes as well. Mosquitoes attracted to the trap are drawn in through the top of the trap and forced downward by the fan into the collection net. Live-trapped females can be counted and tested for mosquito-borne arboviruses.

Gravid Trap

gravid trapThis trap selectively samples gravid (ready to deposit eggs) female house mosquitoes (Cx. pipiens) that are seeking suitable oviposition sites. The gravid trap incorporates three components: a base reservoir filled with oviposition attractant (hay or manure infusion), a vertically-directed suction apparatus and a top mounted collection carton. The intake orifice of the suction apparatus is positioned one inch above the surface of the oviposition attractant. Gravid females attracted by the infusion descend into the base reservoir where they are swept into the suction apparatus and directed upward into the collection carton.

West Umatilla Mosquito Control District

Dedicated to the Protection of Public Health Through the Reduction of Public Health Vectors