38th Annual Meeting of the Society for Invertebrate Pathology

To examine the role of dynamic coevolution between baculoviruses and arthropod species in the maintenance of cross-infectivity, we fed a North American baculovirus to four Eurasian sawfly species. Our results did not support the hypothesis that contemporary coevolution is necessary for a baculovirus to maintain pathogenicity in a range of organisms as the ingestion of OBs from a North American baculovirus reduced larval survival by 51 to 82% in the four Eurasian sawfly species examined in the laboratory, and by 57% in the Eurasian sawfly examined in the field. Probing and microscopic examinations of dead larvae, as well as the absence of carry-over effects in field populations indicated that the inoculated sawfly species failed to produce OBs following exposure to the foreign baculovirus. This study might be the first field trial of a heterologous baculovirus against an exotic species in a forest ecosystem and to the best of our knowledge, baculoviral pathogenicity with abortive infection has never been reported in vivo in the laboratory or in field populations. We caution that special care should be taken with foreign baculoviruses introduced to control exotic pests, especially sawflies, because of their potential pathogenicity to non-target indigenous species.