Taxonomic Status of the Genus Trichagalma (Hymenoptera: Cynipidae), with Description of the Bisexual Generation

Summary

Taxonomic considerations of a monotypic genus Trichagalma have been based on the unisexual generation only, and its taxonomic status—i.e. whether or not Trichagalma is synonymized with Neuroterus—has been uncertain. Female and male adults of the bisexual generation of T. serratae are described. The adult and gall of the unisexual generation and the gall of the bisexual generation are also redescribed. The present results show that the bisexual generation of T. serratae has all the morphological features diagnostic for Neuroterus, as does the unisexual generation except for one feature. Chromosomal examination revealed that the haploid chromosome number of this species is 10, as in most oak gall wasps including three Neuroterus species. Mitochondrial sequence data obtained in a previous study suggest that T. serratae and some species of Neuroterus are in the same clade. No possible autapomorphies are found among the morphological, karyological or molecular characteristics of Trichagalma. Therefore, Trichagalma is synonymous with Neuroterus.