Buffalo Fly: Control & Treatment in Cattle
Cattle producers throughout northern Australia regard buffalo fly (Haematobia irritans exigua) as a serious pest. The buffalo fly is a small external, blood-sucking parasite, up to 4mm in length that feed off cattle and buffalo. They readily spread between cattle, across properties and from introduced cattle, and can cause severe irritation and production setbacks when infestations are high. Buffalo flies bite their host up to 40 times per day, mainly attacking the withers, shoulders, flanks and around the eyes. Cattle rub on infrastructure to find relief, which not only results in damage but causes lesions on the hide of cattle. This reduces hide value and may also restrict access to live export. Flies can also spread diseases such as the bacteria causing pinkeye (Moraxella bovis) and the Stephanofilaria sp. worm, which causes severe skin sores around the eyes and body of affected cattle. Such sores can become infected and attract other flies. The distress that buffalo flies cause can disrupt grazing time and reduce overall feed intake, resulting in productivity setbacks.
Like the cattle tick, the buffalo fly was accidentally introduced into northern Australia from Asia in the 19th century. Since then, this pest has spread across much of the tropical north and as far south as central New South Wales. The prevalence of buffalo fly has fluctuated further south over recent years, with one of the most likely reasons for this being climate change.
Buffalo flies costs the cattle industry an estimated $98 million annually in prevention and production costs, according to a 2015 MLA livestock disease producer survey1.
Chemical treatments are an effective way to relieve cattle from buffalo fly. However, buffalo flies have the ability to build resistance to chemical treatments quickly for a number of reasons:
- Few chemical classes are available to control buffalo fly, so the same chemicals are often used repeatedly within one season and again from season-to-season
- Flies are exposed to sub-lethal amounts of insecticide due to incorrect use of parasiticides (e.g. underdosing)
- Buffalo flies have a short lifecycle so resistant populations can build up rapidly in just one season
- Buffalo flies can travel up to 10kms - so resistant buffalo flies can easily spread across properties
An integrated approach to buffalo fly control should be used to reduce fly numbers to an acceptable level, so that production losses are minimised and cattle welfare isn’t compromised. Non-chemical control methods, such as fly trap tunnels and dung beetles can be used to lower fly burdens and reduce reliance on insecticide use. Culling sensitive cattle and selectively breeding cattle genetically predisposed to carrying fewer flies are also strategies that can be adopted. However, using chemical controls and treatments currently remain the most effective way to manage buffalo flies, particularly when fly pressure is high. Consider the following recommendations when managing buffalo flies with chemical controls:
- Monitor fly pressure and treat accordingly:
- Use short residual treatments (eg. pour-ons) during low fly pressure
- Use long residual control (fly ear tags) during high fly pressure ie. when fly worry is obvious, or when there are 30 flies per dairy cow or 200 flies on beef cattle
- Follow label instructions for correct application and removal of ear tags at the end of their control period
- Co-ordinate the chemical class used for each season with neighbouring properties – a community approach to control and resistance management is important given buffalo flies can travel from one property to the next
- Know the resistance status in your area so that you don’t use actives that may not be effective
- Keep a record of what chemical controls you use to ensure that you rotate chemical actives within a season and from season to season
The following is an example of a 4 year rotational control program for buffalo flies. Note: timings may differ to below, as buffalo fly pressure will vary between seasons and locations.
1. GHD Pty Ltd (Joe Lane), T Jubb, R Shephard, J Webb-Ware & G Fordyce (2015). B.AHE.0010 Final Report: Priority list of endemic diseases for the red meat industry, MLA Australia.
2. MLA Australia (2011) Recommendations for integrated buffalo fly control. www.mla.com.au
3. DAFF, QLD (2011) Production losses due to buffalo fly in cattle. www.daff.qld.gov.au
4. NN Jonsson & DG Mayer (1999) Estimation of the effects of buffalo fly (Haematobia irritans exigua) on the milk production of dairy cattle based on a meta-analysis of literature data. Med Vet Entomol.