Black flies

Black flies, small humpbacked biting flies in the insect family Simuliidae, are common pests wherever there are streams, rivers or other sources of running water. Adult female black flies are blood feeders that attack humans and other animals. Each species of black fly is specific to a certain host. For that reason, black flies that attack birds will not attack mammals, and black flies that attack horses will not attack any other animals.

The adult flies are the source of…