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Submitted to: Great Plains Beef Cattle Handbook
Publication Type: Book / Chapter Publication Acceptance Date: 2/5/1996 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: Horn flies and face flies cost cattle producers millions of dollars each year for insecticides, labor for applications, and production losses. Both species of flies reproduce in fresh cattle dung dropped on pasture and since both species are introduced pests, they lack the natural enemies they had in their native countries. Twenty-two species of parasitic wasps have been identified from horn fly pupae in the U.S. and six species from face fly pupae. However, these parasites prefer to parasitize other species of dung-breeding flies and the parasitism rate of both species of pests flies is usually low. One species of insect parasite has been introduced to combat horn flies. Fourteen exotic species of predators have been introduced to aid in controlling horn flies and face flies but at present, it is not known if any of these species are established. Fifteen exotic species of dung-burying scarabs have been released in Texas and several other states. Dung beetles compete with immature stages of dung-breeding flies for the same food source. Five of the 15 species of dung beetles released are established from California to South Carolina. The effect of these introduced dung beetles on dung-breeding flies has not been fully evaluated, but a decrease in horn fly populations has been noted on cattle in several states when dung beetle populations are sufficient to bury most cowpats within 24 hours after deposition |
