Location: Mosquito and Fly Research Unit
Title: Oviposition preference and development of house flies and stable flies in six substrates from Florida equine facilities Authors
Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 15, 2014
Publication Date: N/A
Interpretive Summary: House flies and stable flies are ubiquitous pests on horse farms, and horse owners spend millions of dollars each year in efforts to control them. Although the larval breeding sites for these pests have been well documented on cattle facilities, little is known about fly larval ecology on horse farms. In this study, conducted at the USDA’s Center for Medical, Agricultural and veterinary Entomology, scientists evaluated a variety of potential fly-breeding substrates from horse farms for their relative attractiveness for egg-laying female flies. And their suitability to grow fly larvae. Female house flies preferred to lay eggs on fresh manure and in manure mixed with pine shavings; these substrates also produced the most flies when eggs were added to them under controlled conditions. House fly larvae were unable to grow in substrates with old manure mixed with hay or soil. In contrast, stable fly females rejected fresh manure and preferred to lay eggs on substrates containing plant material. Stable fly larvae were able to develop on all of the substrates and did best on mixtures of fresh manure and pine shavings. The results suggest options for reducing fly populations by effectively managing equine waste and selecting appropriate bedding materials.
Technical Abstract: House flies, Musca domestica L., and stable flies, Stomoxys calcitrans (L.), (Diptera: Muscidae), common pests on equine facilities, were studied in the laboratory to determine their oviposition preferences and larval development on six substrates commonly found on equine facilities. The substrates were hay soiled with urine and manure, fresh horse manure, pine shaving bedding soiled with urine and manure (<12 h old), pine shaving bedding soiled with urine and manure (aged >72 h in a manure pile), builders sand bedding soiled with urine and manure aged in a manure pile, and aged soil from a an overgrazed field mixed with urine and manure of variable age. Based on the number of puparia recovered from choice tests, fresh manure and the fresh pine shaving substrates were the most attractive for house fly oviposition. These substrates also produced the greatest number of house fly puparia from artificially added eggs. House fly larvae failed to develop into adults in the hay and soil-based substrates. Stable flies preferred to oviposit on substrates with plant material and essentially rejected fresh manure. However, when eggs were added to the substrates, larval development to pupariation was maximal in the fresh manure and the fresh pine shaving substrate, producing numbers of puparia equivalent to the laboratory rearing medium. Stable flies developed in all six substrates but time to puparation was prolonged, puparial weight was reduced and fewer adult flies were produced on the less suitable substrates. An understanding of oviposition preferences and differential larval development of house and stable flies on these substrates provides options for reducing pest populations by effectively managing equine waste and selecting appropriate bedding materials.