Black flies belong to the family Simuliidae, which includes at least 700 different species. Most are generalist feeders that attack cattle as well as humans, deer, and other animals. Black fly larvae live in clean, fastmoving water such as streams and dam outfalls.
Mosquitoes also belong to a large family, the Culicidae, which includes numerous species that attack cattle and other animals. Mosquito larvae live in permanent and transitory standing water, including ponds, tree holes, drainage ditches, and stockpiled tires. Although dairy cattle are sometimes attacked by large numbers of these pests, such problems tend to be very local and short lived.
Biting midges, also called "no-see-ums" or punkies, are tiny biting flies in the family Ceratopogonidae. Adult flies feed on blood, and larvae feed on decaying organic matter in moist soil habitats. Ideal breeding grounds are sometimes created where manure mixes with mud around cattle watering areas and manure lagoons. In some regions of the country, biting midges also transmit the virus that causes bluetongue disease.
Mosquitoes, black flies, and biting midges are also difficult to control. Strategies such as boluses and feed additives that are aimed at fly larvae have no effect on any of these pests because the immature stages do not occur in animal droppings. Whole-animal sprays and pour-ons can provide temporary relief in some cases from horse flies, deer flies, mosquitoes, etc.; read product labels carefully to see which ones claim to control or "aid in the control of" these pests.