Large DNA Viruses That Parasitoid Wasps Transmit to Hosts

Many types of viruses have been identified in parasitoid wasps and other Hymenoptera. Parasitoid wasps also transmit several viruses to hosts through the piercing ovipositors that females use to lay eggs. Most viruses that are known to be transmitted by parasitoids have large double-stranded DNA genomes. We summarize the range of interactions that have evolved between parasitoid wasps and the viruses they transmit. Some viruses are mechanically transmitted to hosts, which can reduce the fitness of wasp offspring. Others have evolved into beneficial symbionts or reproductive parasites that replicate in wasps and hosts. Some large dsDNA viruses have also been co-opted into domesticated endogenized viruses that are vertically transmitted to offspring but still produce virions or virus-like particles that wasps use to parasitize hosts. We conclude by discussing future directions and why parasitoid wasps likely transmit many more viruses than are currently known.