Michigan Mosquito Control Association
PO Box 366, Bay City, MI 48707
office (989) 894-4555 | fax (989) 894-0526
Routine mosquito surveillance is essential for the planning, operation, and evaluation of any effective mosquito control program. All control decisions should be based on as much science as possible. Surveillance will ensure the timing and choice of all mosquito control activities will have a scientific basis. Mosquito surveillance programs will provide a listing of local mosquitoes and the effectiveness of control strategies. Routine surveillance yields the location of breeding habitat and identification of problem sites where control should be concentrated. Survey data will provide vital information, such as: an increase in adult numbers within an area suggesting a need for or increased control; a dominance of one species may indicate missed breeding habitat that can be investigated; or timing treatment to catch the most number of larvae and adults within a given breeding habitat or location. Surveillance will also detect disease activity, allowing for control measures prior to an epidemic.
Mosquito egg surveys utilize an oviposition jar, a black container with a suitable substrate (paper or wood) for female mosquitoes to lay their eggs. The ovitrap is useful for collecting information on container breeding mosquitoes. Counting the number of eggs on the substrate can estimate the number of container mosquitoes that may hatch following the next rain, as well as the number of adult females present within the sampling area.
Larval surveys provide insight into larval mosquito population densities and effectiveness of prior larval control efforts. A white plastic dipper is all that is needed to collect water from small containers to large swamps. Estimates of larval density can be carried out by counting the number of mosquito larvae per dip, using a standard 1-pint dipper. A minimum of three to five dips should be completed at each site. Large habitats, such as a farm pond, may require three to five dips at different points around or within the habitat to best represent the resident larval population. The number of dips and the number of larvae per dip, along with larval stage (instar) information will give control personnel an educated guess as to emergence time and what control effort(s) to use. Some larval habitat cannot be sampled using a standard dipper; soup ladles, turkey basters, large syringes, and manual siphon pumps can be used to collect larvae from hard to sample habitat, such as tree holes, tires, and crevices.
Adult surveys are important to surveillance programs in part as they measure a program’s success, often measuring larviciding success or a need for additional adult control efforts. Adult surveys will also yield information as to type of mosquito habitat within and around the surveillance area. No program will be totally successful in eradicating all mosquitoes. The goal should be to reduce nuisance mosquitoes and mosquito-borne disease threats to an acceptable level.
Citizen calls provide a valuable service in informing mosquito personnel of nuisance mosquito populations. They provide information on probable habitat and future areas to target for control. Confirming the reported mosquito problem and addressing it will not only alleviate that citizen’s problem, but other residents within the area as well; treating a small area can benefit a larger area by addressing the source of mosquitoes.
Habitat mapping and record keeping of mosquito habitat location and application methods are invaluable to mosquito control programs. All mosquito habitats within a given area should be mapped; this is best done by foot, but often aerial photos, government drain maps, and other sources can be utilized. Inspecting by foot will visually confirm mosquito breeding habitat. Records of visits to these mapped sites for treatment or surveillance should be kept, noting presence of mosquitoes and changes in the habitat. Keeping records of habitat quality and where control is needed or taken place will help ensure an effective and efficient control program.