Buffalo flies, Haematobia irritans exigua, are similar to horn flies in size and appearance and in feeding and breeding habits. The buffalo fly is a primary pest of cattle and water buffalo but occasionally feeds on horses, sheep, or wildlife. It is distributed throughout northern Australia and New Guinea and is found in parts of southern, southeastern, and eastern Asia as well as Oceania; it is not found in New Zealand. Its life cycle is similar to that of the horn fly; the adult leaves the host long enough to oviposit on fresh manure, where development occurs. The life cycle may take as few as 7–10 days, depending on weather conditions.
Pathology of Buffalo Flies of Cattle
Buffalo flies irritate and annoy animals, usually biting about the shoulders and withers. Both sexes feed on blood 10–40 times per day. Bite wounds may provide a site for screwworm(Chrysomya bezziana) infection. During hot weather, the flies move to shaded parts of the body. Affected animals suffer blood loss and are irritated by the flies; feed efficiency and production may be notably affected with even 100 flies per animal. Some cattle are allergic to the fly saliva. Dark-colored cattle and those in poor condition attract more flies.
Diagnosis of Buffalo Flies of Cattle
Courtesy of Nichola Calvani, Laboratory of Veterinary Parasitology, Sydney School of Veterinary Science, The University of Sydney.
Courtesy of Nichola Calvani, Laboratory of Veterinary Parasitology, Sydney School of Veterinary Science, The University of Sydney.
Buffalo flies can be identified by their dark color, size (approximately half that of a stable fly), and bayonet-like proboscis that protrudes forward from the head. Buffalo flies stay permanently on cattle and leave only if disrupted or to breed and deposit eggs into dung.
Treatment and Control of Buffalo Flies of Cattle
Control of buffalo fly is based on knowledge of the biology and behaviors of the fly
Insecticidal ear tags are an effective part of the control strategy
Insecticides are only one part of the integrated pest management programs for buffalo fly populations that exploit the biology and behaviors of the flies. Insecticidal ear tags are recommended for fly peak season from late summer to early fall. Cattle producers need to be aware of withholding periods and export slaughter intervals are observed. Many of the chemicals used to treat these flies result in meat residues. Buffalo flies have developed resistance to the synthetic pyrethroids and to some of the organophosphates.
Buffalo fly traps have been developed in Australia. The trap consists of a rounded, clear plastic tent through which the cattle walk. The flies are brushed off the cattle within the tent and are then trapped inside where they die of desiccation. These traps remove ~80% of the buffalo flies each time the cattle pass through. When cattle pass through the trap every day or every second day, sufficient fly control is usually achieved. Other nonchemical controls include fly traps, use of dung beetles disrupting the larval development by breaking up the dung pats and culling highly sensitive cattle.
