Covert infections of Spodoptera exigua multiple nucleopoliedrovirus (SeMNPV) have been detected in laboratory or field populations of the homologous host, S. exigua. Two RNA viruses belonging to the Iflaviridae family (SeIV-1, SeIV-2) were identified in S. exigua transcriptome from different laboratory colonies. The three viruses are vertically transmited and establish persistent infections, and coinfection of individual insects by these viruses is considered likely. In this study, we determined the prevalence of covert infections caused by iflaviruses and SeMNPV in order to identify virus associations in natural S. exigua populations. SeMNPV was detected in the 54% of field-adults, whereas 13% and 8% of insects were infected by SeIV-1 and SeIV-2, respectively. The prevalence of SeIV-1 and SeIV-2 in F1 adults showed higher levels than in parental generation, while the prevalence of SeMNPV decreased from parents to their offspring.

This work has been funded from the Ministerio de Ciencia e Innovación (Spain) by the project number AGL2011-30352-C02-01. C.V. received a predoctoral fellowship from the Universidad Publica de Navarra.

Trabajo presentado en el IOBC-WPRS Working Group Insect Pathogens and Insect Parasitic Nematodes, celebrado en Zagreb del 16 al 20 de junio de 2013.

Peer Reviewed