A pond is a tranquil addition to a backyard or community, however its presence increases the risk of mosquitoes which are not only annoying, but may also carry disease, such as the West Nile Virus. In standing bodies of water, such as ponds, mosquitoes will leave their larvae behind which will take up to one week to mature. This can be controlled or prevented by adding certain types of fish to the pond that are predators of mosquitoes and their larvae.
Gambusia, or mosquitosfish, are a small fish of approximately 1 to 1-1/2 inches in size commonly used for mosquito control. They will consume up to 100 mosquito larvae on a daily basis and, if added to ponds with adequate amounts of vegetation, no feeding is necessary. They have a lifespan of approximately three years and do best in deeper ponds at least 18 inches deep. They prefer sunlight and are active in temperatures above 41 degrees Fahrenheit. If this fish is not native to your state, there may be restrictions or even laws against their use while in other states they may be given to pond owners for free to help reduce the mosquito population. Before putting mosquitofish in your pond it is best to check with your state's Department of Fish and Game or the appropriate government office.
Top-feeding bait minnows are an inexpensive option for controlling mosquitoes in ponds. They are often available for purchase at bait, or tackle shops. This type of fish contributes to mosquito control by consuming mosquito larvae.
Although goldfish are considered bottom-feeding fish, smaller goldfish will eat mosquito larvae when they come across it. Goldfish are generally not considered the best option and should not be your only choice of fish for this type of problem. Add small goldfish to ponds that are also inhabited by some top-feeding fish for the best results. Be sure to add goldfish large enough to be safe from being eaten by larger pond fish.
Guppies are a surface-feeding fish and considered a natural predator of the mosquito. When put in ponds that are infested with larvae they will seek out and consume them. Guppies are easy to find and are often available at pet stores for use in fish aquariums.