The buffalo fly season is just around the corner
Did you know that the buffalo fly (Haematobia irritans exigua) is the second most costly ectoparasite to the Australian cattle industry after cattle ticks?1
Buffalo flies cost an estimated annual financial loss of $98.7 million, as well as causing significant welfare concerns in affected cattle.
These small blood-sucking parasites 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 resulting in pinkeye and lesions around the eyes and body of cattle. The distress flies cause 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 predominantly seen in spring and summer. Populations increase with rising soil temperature and frequent rainfall, stimulating young adult flies to emerge from their pupal stage in the soil and seek out a host on which to live and feed.
With spring now upon us, it’s timely to start thinking about the best way to control this costly parasite.
Control methods should aim to reduce total fly numbers and therefore minimise their impact. “An integrated management program is the most effective way to manage buffalo flies. This also helps in safe-guarding the efficacy of the actives we have available in order to minimise resistance” states Dr Rick White, Bayer’s Grow Technical Services Veterinarian.
Cattle of any age can be affected by buffalo flies, however cattle with dark coats and bulls tend to attract greater fly numbers, with bulls typically showing more signs of distress by their presence. Some cattle can also be hypersensitive to buffalo flies, causing exaggerated reactions (‘allergies’) to very few fly bites. Culling these hypersensitive cattle can be an effective management option to increase the threshold over which chemical treatment is required. Genetic selection, dung beetles and the use of fly traps are also possible non-chemical control methods that may reduce overall chemical use on your property.
When fly pressure is predicted to remain high for a prolonged period of time, or cattle are showing signs of fly worry, long acting chemical control methods such as insecticidal ear tags may be suitable. Ear tags are recommended in beef cattle when there are 200 flies per head or in dairy cattle when there are 30 flies per head; this is the threshold at which production is typically impacted and cattle welfare is compromised.
“It’s essential we are strategic in how and when we use these treatments to prolong the efficacy of the actives we have available. Rotation of actives within a season and from season to season is vital,” Dr White emphasises.
The active used in the shoulder fly seasons 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” advises Dr White. The following year, the ear tag active should be rotated.
“Ensuring fly tags are used correctly is also important in ensuring their efficacy. Follow the label directions to ensure you are using the correct number of ear tags per head and make sure tags are removed at the end of the published efficacy period. In the case of Patriot®, Co-Ral® Plus and Cylence® Ultra, this is 4 months. Applying too few ear tags or leaving them in beyond the published efficacy period may accelerate resistance development” says Dr White.
With buffalo flies able to travel up to 10km, they can readily spread between cattle, across properties and from introduced cattle. “We recommend engaging with your neighbours along with your local animal health advisors to formulate a community based control program. This helps ensure the local buffalo fly populations are controlled by actives that are effective, regardless of where they travel”.
If you would like further information on buffalo fly control programs, contact us on our toll-free number 1800 678 368 or visit www.growsolutions.com.au
1. B.AHE.0010 Final Report: Priority list of endemic diseases for the red meat industries. MLA published 20 March 2015, GHD Pty Ltd (Joe Lane et al)
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