Black Flies
These pests are outside the authority of the Vector Control Program. We offer educational information but do not control or regulate these pests.
About black flies
Black flies, also known as buffalo gnats, are small humpbacked flies that can come in many different colors including shades of black, brown, gray, and yellow.
These flies can be aggressive biters. They often bite during the day time and around the eyes and neckline of humans, as well as domestic and wild animals. Their bites can be painful, but they do not transmit diseases in San Diego County.
Habitat and life cycle
Female black flies lay their eggs in running water, often on submerged objects in streams such as plants, rocks, twigs, or leaves. The eggs hatch and develop in the water until they are ready to emerge as adults. The complete life cycle from egg to adult can last from 6 to 15 weeks.
Adult black flies can often be seen in swarms in the late spring and early summer.
Prevention and control
Fly repellents are somewhat effective in preventing bites but need frequent re-application. It is best to wear pants and long-sleeved shirts in areas with black flies.
Controlling black flies is difficult due to the nature of their breeding sites but there are some products labeled for black fly control. Always follow label instructions.
(858) 694-2888
Popular Services
