Temperature-Dependent Development and Oviposition Behavior of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae), a Potential Biological Control Agent for the European Corn Borer (Lepidoptera: Crambidae)

Trichogramma ostriniae Pang and Chen (Hymenoptera: Trichogrammatidae) was reared continuously for seven generations on its native host, the Asian corn borer,Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae). It took 6.7 d at 33 C and 20 d at 17 C from oviposition to adult emergence with no differences between sexes. Several theoretic models were used to Þt the temperature-dependent growth curves of T. ostriniae. A transformed day-degree model and the HilbertLoganmodelwere themost reliable for predicting temperaturedevelopment ofT. ostriniae. Thewasps reared on O. furnacalis at 27 C by the seventh generation had a lower level of parasitism than wasps from other generations and at other temperatures (17Ð33 C). The number of wasps emerged from individual parasitized egg, and percentage of females produced did not differ for any generations and temperatures. The differences among different generations for the amount and proportion of time femalewasp spent drumminghost eggs didnot showanyhostandgeneration-related trends. The time spent drumming by T. ostriniae female wasps reared for three generations on O. furnacalis and then four and six generations on the rice moth, Corcyra cephalonica (Stainton), differed slightly from the other generations. High variability among the testedwasps indicated that a large number of replicates would be needed to detect the probable differences among generations.