Often called “buffalo gnats” because of their distinctive humped back 

Black flies are small biting flies native to southern California and are a nuisance especially in foothill communities and areas where there is a constant flow of water. They deliver a painful bite that affects both humans and domestic animals. Our agency monitors and controls known sources of black flies, but new breeding site can develop when a new source of running water is introduced. Back yard water features such as fountains and waterfalls can provide habitat for black fly to lay eggs and grow. Turning OFF water features for 24 hours once a week will eliminate a backyard source for black fly development but not run the risk of allowing mosquitoes to grow. If you have seen excessive mosquito activity around your home you can schedule a property inspection by one of our specialists. Fill out an online service request or give us a call. 

Black Fly Biology

Unlike mosquitoes, the aquatic larvae and pupae of black flies require moving water to survive and grow. Common breeding sites range from natural sources like rivers and streams to man-made water features like fountains and fish ponds.

Life cycle

1. The female deposits 200-500 fertilized eggs in or on flowing water.
2. Larvae emerge and attach themselves to rocks or foliage under the water and feed on organic debris that flow by.
3. In 7-10 days the larvae will pupate under water. 
4. Adults will emerge from the pupal case and float to the surface inside a bubble of air.