CpGV-M Replication in Type I Resistant Insects: Helper Virus and Order of Ingestion Are Important

• Main Authors: Aurélie Hinsberger, Christine Blachère-Lopez, Caroline Knox, Sean Moore, Tamryn Marsberg, Miguel Lopez-Ferber
• Format: Article
• Language: English
• Published: MDPI AG 2021-08-01
• Series: Viruses
• Subjects: <i>Cydia pomonella</i>; resistance type I; resistance mechanisms; CpGV; CrpeNPV; baculoviruses
• Online Access: https://www.mdpi.com/1999-4915/13/9/1695

The genetic diversity of baculoviruses provides a sustainable agronomic solution when resistance to biopesticides seems to be on the rise. This genetic diversity promotes insect infection by several genotypes (i.e., multiple infections) that are more likely to kill the host. However, the mechanism and regulation of these virus interactions are still poorly understood. In this article, we focused on baculoviruses infecting the codling moth, <i>Cydia pomonella</i>: two Cydia pomonella granulovirus genotypes, CpGV-M and CpGV-R5, and <i>Cryptophlebia peltastica</i> nucleopolyhedrovirus (CrpeNPV). The influence of the order of ingestion of the virus genotypes, the existence of an ingestion delay between the genotypes and the specificity of each genotype involved in the success of multiple infection were studied in the case of <i>Cydia pomonella</i> resistance. To obtain a multiple infection in resistant insects, the order of ingestion is a key factor, but the delay for ingestion of the second virus is not. CrpeNPV cannot substitute CpGV-R5 to allow replication of CpGV-M.