Directional evolution of parasitoid strategies and contingent host shifts shape the radiation of Darwin wasps (Ichneumonidae)

Current Biology · By Bernardo F. Santos, Silas Bossert, Joan Kolasa, Gavin R. Broad, Andrew M.R. Bennett, Daniell R.R. Fernandes, Seraina Klopfstein, Pascal Rousse, David B. Wahl & Seán G. Brady · 2d ago

Santos et al. use a phylogeny of nearly 700 Darwin wasps spanning all subfamilies to show that parasitoid strategies evolve as directional ratchets. Host shifts remain frequent but occur mainly in idiobiont lineages and become much rarer after transitions to koinobiosis.