Face Flies Already!

Yesterday, amidst our routine fly counts on beef cattle, we encountered a concerning influx of face flies. This year, their presence seems particularly pronounced, with some unfortunate animals bearing as many as 70 of these bothersome insects. Such numbers far surpass the accepted threshold of 10 flies per animal, prompting a heightened awareness of the potential issues they pose.

Resembling common house flies, female face flies predominantly target areas around the eyes and nose of cattle, as well as any wounds or cuts. Feeding on animal secretions, flower nectar, and dung liquid, these pests not only induce significant irritation but also serve as vectors for afflictions like pinkeye and Thelazia eyeworms.

Face Fly Video

The male face fly, primarily concerned with reproduction, spends little time directly on the cattle, preferring instead to perch on foliage, fence posts, and other surfaces. Meanwhile, the female deposits her eggs in fresh cattle manure, where they undergo a transformation from maggot to adult over a span of 2 to 3 weeks, depending on ambient temperature.

Maggot in a Dung Pat on Pasture

Combatting face flies requires a multifaceted approach:

1. Environmental Modifications: Face flies shy away from enclosed spaces, making the provision of sheds or barns a strategic move to offer relief during peak fly seasons.
2. Pasture Management: Regularly dragging or harrowing paddocks can disrupt the flies’ preferred breeding grounds, reducing their habitat and impeding their life cycle.
3. Organic Solutions: For organic producers, approved forms of pyrethrum and other natural repellents offer some relief, though their efficacy may be limited to short durations.
4. Insecticidal Measures: When faced with significant infestations, judicious use of insecticides becomes necessary. However, it’s crucial to apply them only when populations exceed the action threshold. Various methods, including sprays, back rubbers, face rubbers, and dust bags, can effectively target the areas where face flies congregate. Ear tag have shown some control as well.
5. Researching Solutions: VetPestX, a valuable resource for selecting suitable insecticides tailored to specific pasture conditions, can aid producers in making informed choices. https://www.veterinaryentomology.org/vetpestx

By employing a combination of these strategies, producers can mitigate the nuisance and potential health hazards posed by face flies, ensuring the well-being of their cattle and the productivity of their operations. In future issues of the blog, I will discuss biological control.