REPRODUCTION AND DEVELOPMENT OF MUSCIDIFURAX-RAPTORELLUS (HYMENOPTERA, PTEROMALIDAE), A PARASITE OF FILTH FLIES

A gregarious strain of Muscidifurax raptorellus Kogan and Legner was c olonized from eastern Nebraska and evaluated for its potential as a bi ological control agent against house flies. Maturation within the host puparium required 13 d at 30 degrees C, 15-16 d at 25 degrees C, and 31-35 d at 20 degrees C. Although M. raptorellus is gregarious, it par titions its eggs over the host patch by laying 2-3 eggs per host when there is an abundance of hosts but by concentrating oviposition when h osts are scarce. Females are capable of producing 16-20 eggs per day d uring their peak ovipositional period and a total of ca. 150 eggs over their lifetime. A carbohydrate source extended the life of female par asites but did not increase their fecundity appreciably. This species is considered to have high potential as a biological control agent bec ause it is economically mass reared, has a high fecundity rate, and pa rtitions its eggs over the available host population.