Comparative development and performance of artificially reared versus host-reared Diapetimorpha introita (Cresson) (Hymenoptera: Ichneumonidae) wasps

Diapetimorpha introita (Cresson) (Hymenoptera: Ichneumonidae), a native ectoparasitoid of Spodoptera spp. pupae, was reared in the laboratory on an artificial diet devoid of any insect host components. Diet-reared wasps demonstrated a propensity to search for and parasitize natural hosts in a field cage trial. Longevity of the diet-reared wasps was comparable with the longevity of wasps reared on host pupae. Survival rate of D. introita was 61.3% when reared on diet and 76.3% when reared on host pupae. Wasps reared on the artificial diet had longer developmental times, reduced fecundity, and reduced adult weights compared to wasps reared on host pupae. These studies suggest that future research efforts should focus on increasing fecundity and weight of diet-reared wasps and decreasing the mortality and developmental time of wasps reared on the artificial diet. The ability to rear D. introita on an inexpensive, artificial diet significantly enhances the potential of mass rearing this parasitoid for inundative releases against Spodoptera spp.