Submitted to: Proceedings, IOBC
Publication Type: Book / Chapter
Publication Acceptance Date: January 15, 2006
Publication Date: March 2, 2006
Citation: Geden, C.J. 2006. Biological control of pests in livestock production. Proceedings, IOBC. Interpretive Summary: This paper will be published in a formal proceedings of an international conference held in Flakkebjerg, Denmark in November 2005, titled “Implementation of biocontrol in practice in temperate regions - present and near future”. In the article, a scientist at Agricultural Research Service, Center for Medical, Agricultural and Veterinary Entomology, in Gainesville, FL, reviews the current status and future prospects for alternatives to chemical pesticides for pest management in animal agriculture production systems. The review concentrates on pest flies such as house flies and stable flies. It addresses the biocontrol potential of predacious beetles and mites, predacious flies, nematode parasites, parasitic wasps, and fungal and viral diseases of the adult flies.
Technical Abstract: Filth flies have a wide array of natural enemies that can be exploited for augmentative biological control. There are several important predators of fly eggs and larvae, including the mite Macrocheles muscaedomesticae, the histerid beetle Carcinops pumilio, and the black dump fly Hydrotaea aenescens. Mass rearing methods have been developed for these predators, and C. pumilio and H. aenescens are now available as products from commercial insectaries. The most widely used natural enemies are pteromalid pupal parasitoids in the genera Muscidifurax and Spalangia. Rearing methods for these parasitoids are straightforward but require close attention to detail and the biology of the species being produced. The first requirement is an efficient method for mass-rearing hosts; house flies can be grown for $0.50 per 10,000 fly pupae. Pupae are exposed to hosts for about 3 days, using host:parasitoid ratios that ensure high rates of parasitism without causing excessive mortality because of superparasitism. Rearing protocols also need to take into account whether the species is solitary or gregarious and the aggressiveness of parasitoid larvae in superparasitized hosts. Parasitoid releases have been demonstrated to be an effective fly management tool in several studies, including tests in Denmark, New York, Maryland, Nebraska, and Florida. Most filth fly parasitoids are vulnerable to Nosema disease that can cause a 90% reduction in wasp fecundity, but infection can be prevented by careful screening at the time of colony founding and can be controlled by drug and heat therapy. Adult flies are subject to infection with parasitic nematodes and the fungal pathogens Entomophthora muscae and Beauveria bassiana. Of these, B. bassiana has the greatest potential for operational fly control because it is economical to produce, has a long shelf life and can be deployed in a variety of ways. A baculovirus (SGHV) was discovered recently that may hold promise as well; the virus causes hyperplasia of the salivary glands and shuts down ovarian production.