Current Progressive Dairy digital edition

Fly Control

Bill Clymer Published on 04 June 2010
fly control

Flies are just as annoying to cows as they are to people. But two types of flies cause actual discomfort for cows – stable and biting flies. Both of these flies bite and draw blood. Here are some tips for recognizing and controlling them.

Watch for flies that hang around a cow’s legs. If cows are bunching together in a pen and stomping or kicking, stable flies are most likely to blame.



Stable flies develop in spoiled vegetation. A silage bunker, unused hay ring feeder or bedded pack that uses straw are likely stable fly breeding areas. Also know these flies can travel up to a mile. So even if your place is clean, your neighbor could be breeding them for you.

Biting horn flies are typically a problem for pasture cows. These flies can develop in an undisturbed cow pie. Watch for a cloud of flies on a cow’s back that will get off when disturbed but then get right back on.

Examine potential biting flies closely. Both stable flies and biting flies have what looks like a pin needle for a mouth. Look for them on vertical surfaces like a wall or barn support beam. After biting, stable flies like to digest a meal resting on these surfaces. PD

Bill Clymer
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