Buffalo Fly Management

Overview

Cattle producers throughout northern Australia regard buffalo fly (Haematobia irritans exigua) as a serious pest. The buffalo fly already causes significant problems in the Australian beef cattle industry. In a future where climate change may well cause an increased distribution of this pest, it will be more important than ever that cattle producers employ effective management strategies. An integrated approach is recommended for the control of this pest.

The buffalo fly is a small external, blood-sucking parasite, up to 4 mm in length. 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. It is considered to be the most significant health issue affecting cattle in Queensland, with a cost to the industry, according to the MLA in 2005, estimated at $20–$30 million annually.

Buffalo fly irritate cattle, interrupting feeding and causing sores, especially when infestations are high. Trials in the wet tropics have shown that buffalo fly can reduce beef cattle production by up to 16%. A small parasitic worm (Stephanofilaria spp.) is associated with buffalo fly bites and causes skin lesions. Sores from buffalo fly infestations result in permanent hide damage, therefore decreasing the value of the hide. These lesions may also restrict access of stock to the live export trade.

 

Economic Impact

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Resistance

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 10 kms - so resistant buffalo flies can easily spread across properties
Treatment Program
  • Follow the label recommendations so flies are exposed to lethal concentrations of chemical eg. remove tags after the control period (4 months), use the number of tags recommended
    • Monitor fly pressure and treat accordingly:
    • Use short residual treatments (pour-ons) during low fly pressure
    • Use long residual treatments (fly ear tags) during high fly pressure when fly worry is obvious, or when there is 30 flies per dairy cow or 200 flies per beef cattle
  • Coordinate treatment of chemical class with your neighbours
  • Follow the following treatment program from one season to the next

 

Buffalo Fly program for one year

  1. Use a ML (macrocyclic lactone/mectin) pour-on for pre- and post-peak fly season to provide buffalo fly protection for up to 28 days (using Baymec LV, Bomectin Pour-On or Imax CD) or 21 days (for Baymec Pour-On).
  2. Use a fly ear tag during the peak fly season for 4 months protection (using Cylence Ultra, Co-Ral Plus or Patriot). Treatment timing will differ according to seasonal conditions.

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Buffalo Fly program for three years

Use an organophosphate (OP) tag for 2 consecutive years and then change to a synthetic pyrethroid (SP) tag the following year.*

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Keep a record of which chemical class you are using and when to assist following this rotation program year-to-year.