38th Annual Meeting of the Society for Invertebrate Pathology

The baculovirus Anticarsia gemmatalis Multiple nucleopolyhedrovirus (AgMNPV) is the world most successful viral pesticide and is being used in Brazil for the control of the soy bean pest, the velvetbean caterpillar, A. gemmatalis. We have used recombinant AgMNPV viruses to follow the AgMNPV infection and replication inside insect larvae and shown that AgMNPV is able to infect most tissues of its host. We have also characterized A. gemmatalis haemocytes and AgMNPV replication in these cells by light and electron microscopy. Furthermore, we have demonstrated that a mutant AgMNPV derived virus (vApAg) is capable of inducing apoptosis in vivo by accessing vApAg infection in A. gemmatalis haemocytes by intrahaemocoelic innoculation. vApAg also induces apoptosis in a cell culture derived from A. gemmatalis (UFL-AG-286), abrogating protein synthesis at late times post-infection and reducing viral progeny production. Apoptotic bodies and entire cells were phagocytosed by plasmatocytes and granulocytes, and necrosis of infected cells was also observed. The average time of death was extended for vApAg-infected larvae if compared to the time of death by infection with the wild-type virus. These results show correlation of apoptosis occurrence in vivo and the reduced infectivity of vApAg in A. gemmatalis larvae.