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Biological Control

The Mosquito Commission’s Biological Control Program uses fish species that kill and eat mosquito larvae before they develop into adults.  This is a NJ state-sponsored fish stocking program that is part of the Commission’s Integrated Mosquito Management approach to area-wide mosquito control. The Commission maintains and releases three fish species for biological control of mosquito larvae: 
  • Fathead minnow (Pimephales promelas)
  • Banded Killifish (Fundulus diaphanus) and 
  • Mosquitofish (Gambusia affinis)
When used in the appropriate situations, biological control can be an inexpensive, efficient, and environmentally friendly means of controlling mosquito populations. 

Fish are stocked according to guidelines provided by the NJDEP State Mosquito Control Commission (SMCC) and the Office of Mosquito Control Coordination (OMCC). These guidelines limit introduction of the nonnative mosquitofish to contained areas where there is no chance of escape and where larval mosquito populations have been documented. These include unused swimming pools, ornamental ponds, and abandoned sewage lagoons. Native fathead minnows and banded killifish are used in all other areas.  These include stormwater facilities, ditches, freshwater swamps, and woodland pools.

The Middlesex County Mosquito Commission maintains a stock of each species in an outdoor pond and large indoor rearing tanks. Request for fish stocking​.

Fish Rearing Tanks

Fish Pond at MCMEC Headquarters in Edison

Abandoned Swimming Pool Stocked with Fish

Stocking Minnows along the Middlesex Greenway
​Fathead Minnow: Pimephales promelas

The fathead minnow is a commonly used predator of mosquito larvae. This popularity probably originated from the widespread use of the fathead minnow as baitfish or feeder fish, and as the “rosy red minnow” used in aquariums.

Recently, this species has been preferred in many areas for use in mosquito control in because of the ecological problems associated with the mosquitofish.  Although their capacity to consume mosquito larvae is somewhat less than the mosq​uitofish and the banded killifish, this species will easily deplete mosquito populations.

The fathead minnow will readily establish in new areas to provide long-term control of mosquitoes.  The native range covers much of the United States, and it is well suited for conditions in New Jersey.  The Middlesex County Mosquito Commission usually uses this species together with the banded killifish for stocking mosquito habitats.

Native (Orange) and Introduced (Red)
Distrubution of Pimephales promelas
​Banded Killifish: Fundulus diaphanus

The banded killifish is native to the northeastern United States.  It is an excellent predator of mosquito larvae because it is a voracious feeder and it feeds readily at the water’s surface.  It is well adapted to water temperatures in New Jersey and can tolerate moderately saline waters.

This species has been largely overlooked as a mosquito control agent because of the widespread use of Gambusia affinis.  However, since it is native and well established throughout the state, the Middlesex County Mosquito Commission releases this fish, along with fathead minnows to provide long-term mosquito control in habitats where mosquitoes are present but lack a predator population.   

Native (Orange) and Introduced (Red)
Distrubution of Fundulus diaphanus
Mosquitofish: Gambusia affinis

The Western mosquitofish is very efficient predator of mosquito larvae.   This species is native to the Mississippi River Basin but it has been stocked in mosquito infested waters around the world.

Mosqutitofish are popular in the mosquito control industry because the feed close to the water’s surface where mosquito larvae are most commonly found. The species can tolerate a broad range of water conditions, including oxygen-poor environments.

However, since it is not native to New Jersey, introductions may adversely impact other species of aquatic plants and animals because they will feed on many other things when mosquitoes are not present. As a result, the Middlesex County Mosquito Commission only releases this species in enclosed artificial (manmade) bodies of water such as neglected swimming pools or ornamental ponds where there is little chance of escape.

Native (Orange) and Introduced (Red)
Distrubution of Gambusia affinis


Mosquito Extermination Commission
200 Parsonage Road, Edison, NJ 08837
Ph: (732) 549-0665​
Fax: (732) 603-0280
Hours: ​7:00AM to 3:30PM, Mon-Fri

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