Conflicting signal in transcriptomic markers leads to a poorly resolved backbone phylogeny of Chalcidoid wasps

Chalcidoidea (Hymenoptera) are a megadiverse superfamily of wasps with astounding variation in both morphology and biology. Most species are parasitoids and important natural enemies of insects in terrestrial ecosystems. In this study, we explored a transcriptome-based phylogeny of Chalcidoidea and found that poorly resolved relationships could only be marginally improved by adding more genes (a total of 5,591) and taxa (a total of 65), proof-checking for errors of homology and contamination, and decreasing missing data. Concatenation analyses consistently place Mymaridae and Trichogrammatidae sister to remaining Chalcidoidea. However, our coalescent analyses provide a different hypothesis with a grouping of (Mymaridae (((Trichogrammatidae, Eulophidae), (Encyrtidae, Aphelinidae)), remaining Chalcidoidea)). This hypothesis complicates our hypothesis of egg parasitism as being ancestral in Chalcidoidea. At the deeper nodes, the results uncovered a wide spectrum of gene discordance in the ...