BUFFALO FLY MOST COSTLY TO THE AUSTRALIAN BEEF INDUSTRY

Buffalo flies (Haematobia irritans exigua) are small blood-sucking parasites that feed off cattle, biting their host up to 40 times a day. This causes severe irritation when at high levels and can also spread disease-causing organisms resulting in pinkeye and lesions around the eyes and body of cattle. The distress this causes can disrupt grazing time and reduce hide value, resulting in serious welfare and production concerns.

Buffalo flies are prevalent in the northern regions of Australia, closer to coastal regions where conditions are more favourable for their development. Buffalo fly populations build up following an increase in soil temperature and frequent rainfall, typically in spring and summer. Young adult flies emerge from their pupal stage in the soil and seek out a host on which to live and feed.

“Interestingly, the MLA report indicated that seasonal conditions are driving buffalo fly to expand geographically. Fly challenge is becoming greater and lasting longer within a season” Kim Krilich, Brand Manager for Elanco Animal Health comments.

The report acknowledged that controlling buffalo fly is becoming more challenging with increasing resistance development to available chemical treatments.

“This highlights the importance of strategically managing buffalo fly to minimise production losses” Mrs Krilich explains.

Insecticidal treatments remain the most effective way to control buffalo flies, but their use should be carefully considered.

Short-acting insecticides are ideal for use when buffalo fly pressure is low or at the start of the fly season to reduce their build up and provide short-term welfare benefits to affected cattle.

However, if fly pressure is predicted to remain high for a prolonged time, or cattle are showing signs of fly worry, long-acting chemical control methods such as insecticidal ear tags are more suitable. Ear tags are recommended in beef cattle when there are more than 200 flies per head or in dairy cattle when there are more than 30 flies per head; this is the threshold at which production is typically impacted and cattle welfare is compromised.

Insecticide impregnated ear tags work by slowly releasing insecticide in a gradual and consistent dose across the body of the animal. Cattle rubbing against each other can also facilitate the spread of the insecticide. Insecticide ear tags are a practical, convenient, and effective way to chemically control buffalo flies in cattle.

“It’s recommended that chemical actives are rotated within a season and from season-to-season. This is an important consideration when planning your insecticidal treatments this season” says Mrs Krilich.

The active used in a short acting treatment applied at the start of the season should be different to that used in the ear tag. “For instance, if a macrocyclic lactone (ML) drench has been used at the start of the buffalo fly season to control both internal parasites and buffalo flies, a synthetic pyrethroid (SP) ear tag such as Cylence™ Ultra or organophosphate (OP) ear tag such as Patriot™ or Co-Ral™ Plus should be used during the peak fly season. The following year, the ear tag active should be rotated.”

The correct use of fly tags as per the label directions is important in ensuring their efficacy and achieving best results. Applying too few ear tags or leaving them in beyond the published efficacy period can help to accelerate resistance development too.

If you would like further information on buffalo fly control programs or product advice, visit growsolutions.elanco.com or have a chat with your local AIRR Member Store.