[Significance of the Musca domestica antagonist Ophyra aenescens (Diptera:Muscidae). III. Laboratory studies of the interaction between the larvae of M. domestica and O. aenescens].

Laboratory tests were made in order to obtain more detailed information concerning the interaction between the muscid flies Musca domestica L. and Ophyra aenescens (Wied.). Joint breeding of the larvae mostly led to a high mortality rate in M. domestica. There is much probability of the larvae of O. aenescens preying on those of M. domestica, at least in the third larval stage. However, O. aenescens are no obligatory predators and are able to develop normally without consuming fly larvae. The effect on M. domestica depends on the population density of both larvae, on age and quantity relations. When the larvae are combined a short time before they pupate O. aenescens destroys mainly the female larvae of M. domestica. Under test conditions both species showed no difference in survival rate and sex ratio. M. domestica developed somewhat faster than O. aenescens with the developmental time of both larvae depending on population density. A sufficient supply with larvae of M. domestica as protein source can compensate for this delay to a certain degree in O. aenescens.