Horse Flies and Deer Flies

Family Tabanidae

Deer fly (Chrysops mitis). Photo:Stephanie Boucher

Females are bloodsucking and the bites are often painful. They are often serious pests of livestock and humans. The males are found on flowers and feed on nectar and pollen. The adults are often seen around swamps, marshes and ponds. The larvae are aquatic and are mostly found in shallow water or moist soil. Most of the larvae are predaceous. Some species transmit diseases such as tularemia and anthrax in the United States and Africa. Tabanidae are medium to large sized, stout-bodied flies. The eyes are often brightly colored with a pattern of stripes. The eyes touch each other on the top of the head in males and are separated in the females. The wings of deer flies often have a distinct dark pattern. The calypter is well developed at the base of each wing.