Buffalo fly (Haematobia irritans exigua) remains one of the most significant external parasites affecting Australian cattle. Buffalo fly was ranked first as the costliest disease to the cattle industry by Meat & Livestock Australia in 20221. Although traditionally associated with northern Australia, its distribution has expanded southwards in recent decades. An integrated approach to the management of buffalo fly is crucial for reducing the production and economic impacts to your herd.
Adult buffalo flies are small, grey flies measuring approximately 3.5 to 4 mm long. They are commonly found on the back, shoulders, flanks and belly of cattle, often in large numbers. Unlike nuisance flies that feed on secretions, buffalo flies have piercing mouthparts and bite cattle repeatedly to obtain blood meals. Individual flies may feed 10 to 40 times per day1. Flies only leave cattle briefly to lay eggs in freshly deposited dung. Under warm, moist conditions, the lifecycle from egg to adult can take as little as 12 to 14 days, allowing fly numbers to increase rapidly during the season2.
The bites are highly irritating and can cause characteristic signs of “fly worry”, including frequent tail swishing, head tossing, skin twitching, stamping of feet, reduced grazing time and animals standing together to avoid flies. Chronic infestations can also lead to skin lesions around the eyes, neck, dewlap, brisket and flanks. These lesions may range from hair loss and scabs to severe ulcerated wounds.
Buffalo flies can negatively affect the welfare of cattle as irritation causes stress and behavioural changes, while lesions can become chronic and predispose animals to secondary infections. Research has demonstrated that heavy infestations can reduce liveweight gain in beef cattle by up to 16%. In dairy cattle, infestations exceeding 30 flies per cow can reduce milk production by up to 0.5 litres per cow per day2.
The economic burden of buffalo fly is substantial. Estimated annual costs to the Australian cattle industry exceed $170 million when both production losses and prevention costs are considered1. These losses arise from decreased weight gain, animal welfare impacts, treatment costs and hide damage.
As buffalo fly continues to expand into new regions, maintaining effective control programs will remain critical. Integrated management aims to ensure the welfare of cattle and reduce fly numbers while minimising reliance on insecticides and slowing the development of resistance3.
Key strategies include:
- Monitoring fly numbers and delaying treatment until economically important thresholds are reached, generally around 200 flies per beef animal or 30 flies per dairy cow.
- Reducing fly numbers by usin non-chemical methods, such as buffalo fly traps and dung beetles, when possible. Traps have been shown to reduce fly numbers by up to 60 to 70% but can be challenging to use effectively.
- Breeding for resistance and culling animals that consistently develop severe lesions or display hypersensitivity to buffalo fly challenge.
- Using treatments that are still effective on your property and integrate fly control into worm and tick control programs.
Chemical control remains an important component of buffalo fly management, particularly when fly numbers exceed economic or welfare thresholds. Treatment options include ear tags, sprays, back rubbers and pour-ons. Resistance to some insecticide classes is widespread, producers should seek advice from their animal health advisor to create a suitable treatment plan for their region.
When control of other parasites (such as worms, ticks and lice) is needed, integrating a macrocyclic lactone (ML) into whole-herd parasite control programs can offer additional value compared to other treatments. Ivomec® Pour-On and Ivomec® LV (low-volume) are pour-on treatments containing ivermectin (a type of ML) which provides effective parasite control, including buffalo fly for up to 21 days after treatment*.
As with all parasite control products, producers should use registered products according to label directions and consider them as part of a broader integrated management program.
Buffalo fly remains a major production, welfare and economic challenge for Australian cattle producers. A planned, integrated approach will deliver the best outcomes for both cattle performance and long-term buffalo fly management.