Reproduction and survival of overwintered and F1 generation of two egg parasitoids of sunn pest, Eurygaster integriceps Put. (Heteroptera: Scutelleridae)

The differences in the reproductive biology of overwintered (OW) and F1 generation of Trissolcus semistriatusNees and T. festivae Victorov (Hymenoptera: Scelionidae) were investigated under laboratory conditions. The experimentswere conducted to evaluate oviposition period, lifetime fecundity, female progeny, sex ratio, and longevity of OW and F1generation with the two species as factors. The results of this study showed that the oviposition period of F1 generationwas longer than that of OW females for both of the two parasitoid species. With the exception of F1 generation of T.festivae, the highest daily average progeny production of females was recorded on the first day. The mean lifetimefecundity of ovipositing females were calculated as 88.8 ± 6.13 and 111.9 ± 6.66 for OW and F1 generation of T.semistriatus, 85.6 ± 6.83; 104.7 ± 4.66 for OW and F1 generation of T. festivae, respectively. The sex ratios of progeny forboth of the species were distinctly female-biased. The effects of species, factors (OW and F1 generation), and theirinteractions were significant on the sex ratio of progeny. The average longevity of OW females was 16.2 ± 1.76 days forT. semistriatus and 16.9 ± 1.21 for T. festivae. The average longevity of F1 generation females was 17.5 ± 1.46 days for T.semistriatus and 28.5 ± 1.94 for T. festivae. Thus, some several biological characteristics of both species were comparedand discussed with regard to the use of OW populations for the successful implantation of biological control and massproduction.