Adaptations to different habitats in sexual and asexual populations of parasitoid wasps: a meta-analysis

Isabelle Amat (1) , Jacques J.M. van Alphen , Alex Kacelnik (2) , Emmanuel Desouhant (1) , Carlos Bernstein (1)

1 Evolution, adaptation et comportement
2 Department of Zoology [Oxford]

Background. Coexistence of sexual and asexual populations remains a key question in evolutionary ecology. We address the question how an asexual and a sexual form of the parasitoid Venturia canescens can coexist in southern Europe. We test the hypothesis that both forms are adapted to different habitats within their area of distribution. Sexuals inhabit natural environments that are highly unpredictable, and where density of wasps and their hosts is low and patchily distributed. Asexuals instead are common in anthropic environments (e.g., grain stores) where host outbreaks offer periods when egg-load is the main constraint on reproductive output.Methods. We present a meta-analysis of known adaptations to these habitats. Differences in behavior, physiology and life-history traits between sexual and asexual wasps were standardized in term of effect size (Cohen's d value; Cohen, 1988).Results. Seeking consilience from the differences between multiple traits, we found that sexuals invest more in longevity at the expense of egg-load, are more mobile, and display higher plasticity in response to thermal variability than asexual counterparts.Discussion. Thus, each form has consistent multiple adaptations to the ecological circumstances in the contrasting environments.

Mots clés: Venturia canescens; Maintenance of sex; Local adaptation; Trade-offs

Domaines: Biodiversité et Ecologie; Zoologie des invertébrés; Evolution [q-bio.PE]

Isabelle Amat, Jacques J.M. van Alphen, Alex Kacelnik, Emmanuel Desouhant, Carlos Bernstein. Adaptations to different habitats in sexual and asexual populations of parasitoid wasps: a meta-analysis. PeerJ, 2017, 5, pp.e3699. ⟨10.7717/peerj.3699⟩. ⟨hal-02070503⟩