Biological parameters of the egg parasitoid Ooencyrtus gonoceri

Ooencyrtus gonoceri Viggiani (Hymenoptera Encyrtidae) is a poorly known egg parasitoid species with an apparently rare occurrence in the Mediterranean basin. It was originally identified in southern Italy emerging from Gonocerus acuteangulatus (Goeze) eggs and successively recorded also from Spain. Recently O. gonoceri emerged from sentinel egg batches of Halyomorpha halys (Stal) (Hemiptera Pentatomidae) in central Italy. Due to the scanty data on this species, biological and demographic parameters of O. gonoceri were investigated under laboratory conditions on the alternative host Graphosoma italicum italicum (Muller) (Hemiptera Pentatomidae). Estimated fecundity was over 200 eggs/female and the mean progeny production per female was high (173.76 specimens). At the standard rearing condition (26 °C) the development time of both sexes was similar and adults emerged after two weeks. Moreover O. gonoceri females lived much longer than males and the host feeding behaviour resulted irrelevant for the parasitoid longevity. The main biological parameters of O. gonoceri were similar to those reported for other cogeneric species. However, this species appeared to be a very effective egg parasitoid if compared with Ooencyrtus telenomicida (Vassiliev) reared on the same host.