The Horn Fly is a very tough pest to control and seemingly resistant to most every chemical control. It only reproduces in cow pastures, which means there is always breeding material in the manure and research shows that as few as 200 Horn Flies per cow is the starting point of production losses. A loss of 15% in milk production has been reported during summer months and a 10% reduction in lifetime milk production has been reported from sub clinical mastitis in young stock caused by Horn Flies before the first lactation. For the past 16 years, North Carolina State University entomologists, Dr. Wes Watson and Steve Denning, have been researching IPM practices for pest fly control for commercial livestock and poultry operations. Horn Flies have been a target for much of their work.
