Fly Frustrations

Erica Sayles |  July 19, 2021

‘Tis the season for the inevitable onset of growing fly populations on farms. Flies are not only annoying to both people and animals, but they can pose a health threat by spreading diseases and infections, and ultimately reduce milk production. Based on research, high populations of stable flies can reduce milk production by 15-30% (Central Life Sciences, 2021).


 So what do we know and what can we do about it?    

Manure is a primary food source and breeding site for flies- we can minimize this by scraping stalls regularly, removing soiled bedding, keeping hutches and enclosed areas as manure-free as possible. Any type of “spoilage” on a farm is very attractive to flies. 

Removing spoiled feed and milk spillage will help you stay on top of the population and keep your cows and calves relaxed and pest-free. For calf bedding, do the ‘knee-drop’ test. If it is wet it may require the bedding to be cleaned out more frequently than other times of the year. Also, look in and around calf feeding areas as calves tend to make a larger mess when drinking milk than may appear at first glance.

Grasses and weeds are ideal places for flies to rest. By cutting these low around barns, feeders, and manure piles reduce places for flies to hide.


Flies feed at a low level, breed at mid-level, and rest at a high level. Place your pest control options accordingly. As they feed at a low level, ie. the ground; scattering baits in this area is the best place to target them at feeding. To target them while they are mating look higher than they eat but lower than they rest. 

This is a good area to place pheromone traps. Think fence lines, short walls, and shelves in barns. Finally, flies rest up high. So placing sticky traps or strips above stalls and in rafters out of animal reach is a good way to target them at rest.


In our store, we have a variety of fly control options including sprays, baits, and sticky traps/string that can be picked up or added to a delivery.


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