Introduction of Entomophthora muscae (Zygomycotina: Entomophthorales) to Caged House Fly Populations

Abstract

Experiments for the introduction of Entomophthora muscae to populations of the house fly adults were carried out. Rearing of 50 healthy flies in a 27-l cage with 1, 4, or 10 fresh cadavers attached to the inside top of the cage as conidial sources initiated death of flies from approximately 6 days after introduction. Including secondary infections, the fly populations finally collapsed within 11 days with the application of more than 4 cadavers. When 2, 4, or 10 living flies injected with E. muscae protoplasts were released into the population of 50 healthy flies in a 27-l cage, the 1st mortality peak of non-injected flies occurred 4 to 6 days after the death of the injected flies, and the 2nd peak of mortality detected several more days after this. The non-injected flies were totally killed within 17 days by releasing more than 4 living infected flies. The epizootics also occurred when more than 2 conidia-discharging cadavers were attached within a 0.8-m³ cage, and the population of 50 healthy flies were killed within 14 days. Both the application of fresh fly cadavers and release of living-infected flies were thought to be effective means of introduction of E. muscae into house fly populations.