Lady beetle “guarding” a wasp cocoonFANNY MAURETwenty days after a fateful bite from a parasitoid wasp (Dinocampus coccinellae), a pre-pupa emerges from the bitten lady beetle (Coleomegilla maculata) and spins a cocoon between the beetle’s six legs. Eventually, the beetle becomes immobile, twitching and shaking at irregular intervals, grasping the wasp cocoon as if its own life depended on it. To force C. maculata into bodyguard duty for its young, the wasp is aided by a virus—D. coccinellae paralysis virus, or DcPV—that partially paralyzes the lady beetle, according to a study published today (February 10) in Proceedings of the Royal Society B.
Viral mediation of host-parasite interactions are nothing new. However, this study was the first to find “that a virus is involved in the behavioral manipulation by another parasite,” said Nolwenn Dheilly of Stony Brook University in New York, who led the study.
Studying C. maculate-D. coccinellae interactions in the lab, Dheilly and her colleagues found that the onset of beetle behavioral modification occurred long after the bite and oviposition by the wasp. Moreover, once adult wasps emerged from the beetle-protected cocoons, the beetles recovered from the paralysis, resumed feeding, and even went on to reproduce. To tease apart competing hypotheses on this transient, behavior-modifying viral infection, Dheilly’s team scanned the beetle, wasp, and DcPV genomes. The researchers stumbled upon an odd cluster of transcripts that ...
