Nuisance Flies
Flies are a nuisance for both livestock and people causing stress and irritation. Under typical UK climatic conditions up to 15 generations of flies can be produced in just one year.
In cattle, flies can cause:
- Reduced weight gain
- Up to 12.9% reduced feed efficiency in calves in cases of fly challenge1
Flies can also transmit diseases:
- New Forest Eye (Moraxella bovis)2
- Summer Mastitis (Hydrotea irritans)3
Fly species
The most common species affecting cattle are:
- Horn fly (Haematobia irritans)
- Head fly (Hydrotea irritans)
- Stable fly (Stomoxys calcitrans)
- Face fly (Musca autumnalis)
Timing
The main months for fly problems are May, June, July and August. However, with unpredictable weather patterns, fly problems can start in April and last into October.
Treatment
It is of certain importance to consider how to prevent fly problems in cattle. For example, in dairy cattle, fly control has proven to provide up to 2.6% increase in milk production4
In cattle, there are two main methods of treatment for flies:
- On-animal
- Environmental
The most popular method for cattle is on-animal as, during the fly season, most animals are out in the fields. However, this should not exclude treating the environment, as areas on the farm like dung heaps, calf pens and slurry pits can be ideal fly breeding grounds and act as a reservoir for flies.
On-animal fly control
Ear tags are available but the most commonly used products on cattle are pour-ons.
- All are based on synthetic pyrethroids
- Kill flies by affecting their nervous system
- Spread following application, to cover the body
- Offer various actives and formulations
- Offer various lengths of protection
- FLYPOR® is a good solution for on-animal fly control and is available in an easy-to-apply, low cost pour on. It provides long lasting, broad spectrum control of nuisance and biting flies and also controls lice and treats both chorioptic and sarcoptic mange on cattle
Environmental control
By reducing fly breeding sites, efficient dung/waste management, good drainage and drain management will help limit fly problems.
Chemical methods can also play a valuable role in controlling the fly population by breaking the fly life cycle. As adult flies are only 20% of the total fly population, with immature eggs accounting for 80%, it is advisable to use a larvacide and adulticide concurrently.
Larvacides:
- Kill the larvae (maggots)
- Stop larvae from ever developing into flies
- Cyromazine (NEPOREX®) is an environmental larvacide available in the UK
- For maximum effect, adulticides and larvacides should be used concurrently
Fly breeding areas for larvacide treatment:
- Anywhere manure accumulates
- Areas where urine, faeces, and feed are found
- Calf pens with wet bedding
- Pens for sick animals
- Silage storage areas
Adulticides:
- ‘Knock down’ products kill flies on application, e.g. classic fly sprays
- ‘Residual’ products such as OXYFLY®, containing lambda-cyhalothrin, and SpY®, based on the natural product spinosad, continue to kill flies after application
- Use residual products where adult flies rest:
- Posts
- Milking pipes
- Sunny wall areas
- Window frames
- Lights
- Feed troughs
- SpY®, containing spinosad, has no cross resistance with other fly control insecticides
Always use pesticides/biocides safely.
Related products
Links
References
- Stork, M.G. (1979): The epidemiological and economic importance of fly infestation of meat and milk producing animals in Europe. Vet.Rec., v. 105, p. 341–343.
- Gerhahrt et al 1982
- Yeruham et al 1996
- Jonsson. N. N & Mayer. D. G. (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. Medical and Veterinary Entomology, v. 13. p. 372-376.








