Insecticides of different Mode of Action (MoA) classes were tested for their ability to reduce horn fly populations on cattle in Nebraska pastures between 2009 and 2016. Macrocyclic lactone products were the most efficacious, reducing horn fly numbers by an average of 93% over ten location years of testing. Organophosphate and pyrethroid MoA products, tested in 7 and 12 location years, reduced fly numbers by 75% and 73%. Classes tested only once were METI (88% reduction) and a combination of organophosphate + pyrethroid (64%)
