Face Fly (Diptera: Muscidae)—Biology, Pest Status, Current Management Prospects, and Research Needs

Native to Europe and Central Asia, face flies (Musca autumnalis De Geer, Diptera: Muscidae) were unintentionally introduced into North America and became pests of pastured beef cattle, dairy cattle, and horses. Female and male flies use their sponging proboscis with prestomal teeth to feed around moist, mucus membranes of an animal’s face and other body parts. While feeding, face flies agitate livestock and elicit defensive behaviors (e.g., ear flapping, head shaking and batting, hiding in deep shade, and adjustment of grazing), and they can transmit eye-inhabiting nematodes and pathogenic bacteria that cause pinkeye. Face flies can be partially controlled with feed-through insecticides that prevent development of face fly maggots in fresh cattle dung pats. Adults can be partially controlled with repellents and insecticides applied directly to animals. Trap-out tactics can be effective and may involve sticky traps placed around high animal traffic areas, such as waterers and feeders in pastures, dairy entryways, or wherever else livestock congregate in pastures. A review of the insect biology and life stages, physical and economic damages, surveillance strategies, and management options for the face fly is presented.