Origin and evolution of symbiotic viruses associated with parasitoid wasps

Parasitic wasp‐associated symbiont affects plant‐mediated species interactions between herbivores

“…A large body of evidence has shown that PDVs manipulate caterpillar physiology to the benefit of their symbiotic partners (Pennacchio & Strand ; Strand & Burke , ; Drezen et al . ). Although the focus of this paper was to unravel the ecological effects of PDVs on plant‐mediated interactions between herbivore species, the hypothesis that PDVs could also manipulate plant physiology to benefit their associated parasitoids merits further investigation.…”

“…; Drezen et al . ) and it has been shown that the venom often synergises with PDVs (Asgari ). Alternatively, PDV genes might be exclusively expressed in the caterpillar body in the presence of the venom as found during in vitro experiments in the closely related host–parasitoid system Pieris rapae ‐ C. rubecula in which the venom is suggested to assist uncoating of viral particles (Zhang et al .…”

“…; Drezen et al . ); however, the ecological effects of such third‐trophic level symbionts have not been investigated so far in a plant‐insect context. To unravel the complexity of plant‐insect interactions and arms races between plants and herbivores, the involvement of the third‐trophic level is crucial because plant traits may enhance top‐down herbivore suppression by natural enemies (Price et al .…”

Mutualistic viruses and the heteronomy of life

“…Mutualism is not a yes/no question, but rather a question of degree, and moreover it is often a contextual question (it depends on spatial and temporal conditions) (Méthot & Alizon, 2014;Van Baalen & Jansen, 2001 phenomenon has been known for more than thirty years (Edson, Vinson, Stoltz, & Summers, 1981), but it is only recently that it has been understood in detail ( (Espagne et al, 2004); (Bézier et al, 2009); (Herniou et al, 2013); (Drezen, Chevignon, Louis, & Huguet, 2014)). …”

“…However, one of the reasons why polydnaviruses are so fascinating is that, even though they have evolved into vertically transmitted agents, they continue to function in many respects like more traditional viruses ( (Herniou et al, 2013); (Drezen et al, 2014); (Strand & Burke, 2014); (Strand & Burke, 2015)). As noted by Herniou et al (2013), bracoviruses in particular are not fossil genomic remnants but active viruses, unlike most endogenous viral elements.…”