Reproduction and Development of Trichomalopsis Species (Hymenoptera: Pteromalidae), a Parasite of Filth Flies

A Trichomalopsis sp. near americana was colonized from eastern Nebraska and was evaluated for its potential as a biological control agent against house flies. Maturation within the host puparium required 13 days at 30°C and 16 days at 25°C. Essentially no maturation occurred at 20°C, and 10 days at 20°C was sufficient to induce arrested development in the third instar in about 67% of the parasites. Trichomalopsis sp. is gregarious and prefers to oviposit repeatedly on single hosts even when other hosts are readily available. Females are capable of producing 10-12 eggs per day and a total of about 110 eggs when adequate hosts and a carbohydrate source are available. This species is not considered to have high potential as a biological control agent because of its preference to sting only 2-3 hosts per day, its relatively low fecundity, and its low incidence in nature.