Mosquito Control & Surveillance

Mosquito Complaint Investigation


Environmentalists respond to complaints about mosquitoes. Inspectors attempt to determine the source(s) of the mosquito problem afflicting the citizen and then recommend or conduct the necessary abatement. The majority of complaints about mosquitoes are caused by the Asian tiger mosquito. This mosquito cannot be effectively controlled by either larviciding or adulticiding. Larvae are found in water-filled objects such as waste tires. Control is achieved by locating the source and overturning, disposing or modifying the source. The inspectors are an important part of the mosquito control program providing personalized service.

Mosquito Surveillance


One of the most important operations of the SCHD Countywide Mosquito Control program is surveillance. Mosquito surveillance program consists of seasonal surveillance technicians and an entomologist. Surveillance is performed daily during mosquito season (April-November). Technicians set mosquito traps, collect trap samples, identify trap collections and process mosquito pools (i.e. samples). There are two forms of surveillance, nuisance mosquito surveillance and arboviral surveillance. Two different types of traps are utilized to collect mosquitoes; New Jersey Light Traps for nuisance mosquito species and Gravid Female Traps for vector (i.e. disease spreading) species. Traps are placed weekly at designated locations throughout the County.

Nuisance surveillance focuses on the identification and determination of the estimated size of mosquito and larval populations. Surveillance information and data are analyzed to determine the need for larviciding and adulticiding.

The mosquitoes collected from the gravid traps are sent to the Tennessee Department of Health Laboratory in Nashville for arboviral analysis. The focus of the control program is West Nile Virus. Mosquitoes are also tested for St. Louis Encephalitis (SLE). The data collected is used to estimate vector densities, describe the dynamics of disease outbreaks, assess risk and a variety of technical measures. Areas where mosquitoes are found to be infected by positive tests for West Nile Virus are targeted for aggressive control measures.