Biological control is a control methodology that involves the use of either native or introduced predators and/or parasites of mosquitoes.
A. Predator fish are used to control immature mosquitoes in permanent waters (ponds, ornamental ponds, ditches) or semi-permanent waters (rice fields, ditches). Some of the species used include:
1. Gambusia affinis, primary top minnow for mosquito control
2. Poecilia reticulata, the common guppy, another top minnow species
3. Heterandria formosa, the least killfish, a common native Louisiana species
B. The fungal mosquito pathogen Lagenidium giganteum is used for specific water habitats (fresh water, from temperatures of 16-32°C). Besides being host specific, L. giganteum has the ability to recycle for weeks, months or even years in a given breeding habitat after a single application.
C. Other biocontrol agents such as the predaceous mosquito Toxorhynchites , predacious copepods and the parasitic nematode Romanomermis have been shown effective by researchers, but are not widely used or commercially available.
D. Operational Factors
1. Inspector(s) who perform larviciding activities should also implement biological control when directed.
2. Biological control is routinely performed throughout the mosquito season and depends on the specific target species and body of water.