author(s)
RK Gupta, Ramandeep Kour and Mudasir Gani

abstract
The interactions between two solitary endoparasitoids, Glyptapanteles agamemnonis (Wilkinson 1932) (Hymenoptera: Braconidae) and Meteorus pulchricornis (Wesmael 1835) (Hymenoptera: Braconidae) and the parasitoid - virus were explored towards healthy vs. Nucleopolyhedrovirus infected and parasitized vs. unparasitized Spilarctia obliqua (Walker 1855) (Lepidoptera: Arctiidae) larvae to understand the outcome of within-host competition. The results revealed lack of discrimination in the behaviour of both the parasitoids towards virus infected S. oblqua larvae within 48 hrs (from ingestion of virus contaminated diet upto 48 hrs) of viral infection. However, discrimination became evident 48 hours post-infection in the form of antennal contacts. Interestingly, no significant difference was observed in the number of ovipositor insertions. The parasitoids also failed to discriminate between unparasitized larvae and larvae parasitized by either of the two parasitoids. It was found that almost all (>99 per cent) the host larvae which were first infected with virus and then exposed to parasitoids for parasitisation succumbed to virus. However, when the host larvae were treated with virus 4 to 6 days post-parasitism, more than fifty per cent of parasitoids managed to complete their development. The effect of virus on the parasitoids was therefore dependent on the interval between parasitism and viral infection and postponing the exposure of pre parasitized larvae to baculovirus infection increased the survival of both the parasitoid species. In case of simultaneous parasitisation of the host larvae by both the wasp species, M. pulchricornis out competed G. agamemnonis. In general, the parasitoids oviposition behaviour was not affected by the virus-infected and parasitized hosts. However, for the sake of successful parasitoid emergence, viral applications must be done few days after parasitoid release in augmentative bio control programmes.