This SOP describes the materials and methods to perform larval surveys of anopheline mosquitoes.
Description: Larval sampling involves capturing immature mosquitoes from aquatic habitats.
Target species and physiological states: Captures larvae and/or pupae of many species.
Entomological surveillance indicators: Larval sampling is used for the full range of immature vector indices, and in addition, larvae can be reared and used as specimens for insecticide resistance bioassays.
Advantage: The equipment and supplies and inexpensive and portable.
Disadvantage: Larval sampling is a poor indicator of adult production. This method it is labour intensive to use and requires trained staff as it can be difficult identify larvae to species. Experience is important as the more samples a person does, the better at larval surveys one becomes. Cryptic habitats are easily missed.
Data: Total number of larvae and pupae per aquatic habitat or dipping effort. Larvae can be recorded by early or late instars. Alternatively, presence or absence at each site can be recorded. When necessary, field data is merged with the results of subsequent laboratory analyses.