This tiny, humpbacked fly can congregate in tremendous numbers around horses, causing extreme annoyance and itching. They feed most commonly inside the ear but also are found on the head, neck, chest and abdomen. Their bite can cause hemorrhage and bloody crusts. Larvae develop in fast moving rivers and streams. Two genera, Culicoides and Leptoconops are major pests to horses.
Lesions consist of self-inflicted hair loss and excoriations with crusting.
Larvae develop in aquatic habitats and decaying vegetation and manure. These Insects feed on horses in great numbers and can produce significant blood losses and annoyance. Skin eruptions can appear on horses bitten by mosquitoes. Mosquitoes reproduce in large numbers in standing water found in marshes, irrigated pastures, abandoned tires and old feed pans. Many species can fly several miles from their breeding sites to feed.