An integrative approach to species discrimination in the <i>Anagrus atomus</i> group <i>sensu stricto</i> (Hymenoptera: Mymaridae), with a description of a new species

Egg parasitoids of the genus <i>Anagrus</i> Haliday (Hymenoptera: Mymaridae) are natural enemies of many pests around the world. We used an integrative approach to characterize some species belonging to the <i>Anagrus atomus</i> group, using specimens reared from leafhoppers infesting some Lamiaceae. Starting from morphological identifications based on available keys, we carried out a multi-locus genetic characterization using phylogenetic and species delimitation analyses, and integrated it with biological and morphometric evidence. This approach revealed the existence of a new species, <i>A. nepetellae</i> sp. nov., here described along with its phenological traits. The approach also allowed us to characterize the expected taxonomic stability of other putative species within the group. We propose two new species groups called the <i>atomus</i> group <i>sensu stricto</i> and the <i>vilis</i> group, with the goal of streamlining the taxonomy of the <i>atomus</i> group. We also present a key for the identification of females of the European species of the <i>atomus</i> group <i>sensu stricto</i>. Some specimens show heterozygosity in 28S-D2 sequences, suggesting hybridization between <i>A. atomus</i> and <i>A. nepetellae</i>, which, if it is common between other species as well, could partly explain the taxonomic problems in the genus <i>Anagrus</i>. DNA sequencing of specimens reared by the same biofactory at different times suggests involuntary contamination leading to the displacement of a laboratory strain of <i>A. atomus</i> by <i>A. nepetellae</i>, which may have resulted from undetected partial reproductive compatibility.http://zoobank.org/urn:lsid:zoobank.org:pub:DFCD7654-5AA5-4E4F-AE48-24377BAACEFE