EFFECTS OF THE TIMING OF ENTOMOPOXVIRUS ADMINISTRATION TO THE SMALLERTEA TORTRIX, ADOXOPHYES SP. (LEPIDOPTERA, TORTRICIDAE) ON THE SURVIVAL OF THE ENDOPARASITOID, ASCOGASTER RETICULATUS (HYMENOPTERA, BRACONIDAE)

Infection of larvae of the smaller tea tortrix, Adoxophyes sp., by an entomopoxvirus (AsEPV) adversely affected the development and survival of the endoparasitoid, Ascogaster reticulatus. Percentages of emergen ce of parasitoid larvae that developed in AsEPV-infected hosts were si gnificantly lower than those of parasitoid larvae that developed in no ninfected hosts. The percentages of emergence of A. reticulatus were s ignificantly greater for parasitoids developing in the host larvae tha t were exposed to AsEPV in third and fourth instars than for the paras itoids developing in the host larvae that were exposed to AsEPV in fir st and second instars. Successful pupation and eclosion of parasitoids significantly increased as duration between parasitization and admini stration of AsEPV increased. No parasitoid larvae developing from host s that were inoculated with AsEPV in the first or second instars pupat ed and emerged as adults, whereas 13.8 and 54.0% of parasitoids develo ping from the hosts that were exposed to AsEPV in the third and fourth instars, respectively, pupated. The development of parasitoids in AsE PV-infected hosts was delayed. This developmental retardation was more severe in parasitoid larvae developing in the early-infected hosts th an in those developing in the late-infected hosts. The average times r equired for death due to AsEPV infection were significantly shorter in parasitized hosts than in non-parasitized hosts. Significant numbers of parasitized and infected larvae exhibited apolysis in preparation f or the final larval molting. This abnormal metamorphosis appeared to b e a possible reason for the earlier death of the parasitized and infec ted hosts. (C) 1998 Academic Press.