A new species of Diglyphus Walker (Hymenoptera, Eulophidae) from China, with notes on its biology and a key to the Chinese species

A new species of <i>Diglyphus</i> Walker, <i>D. albifemur</i> Liu, Hansson & Guo, sp. nov., is described based on extensive material from China collected from 2016 to 2024. The entire material included here has been reared from agromyzid leafminers (Diptera, Agromyzidae), mainly from <i>Phytomyza vitalbae</i> Kaltenbach, mining leaves of <i>Clematis orientalis</i> L. The new species is morphologically similar to the European species <i>D. clematidis</i> Navone & Hansson and shares the same host plant genus (<i>Clematis</i>) but can be distinguished by several diagnostic features detailed herein. Mitochondrial cytochrome c oxidase subunit I (COI) sequences of the new species are provided. The identification key to Chinese <i>Diglyphus</i> species by Zhu et al. (2000) was extended to incorporate the new species and all other Chinese species described since that publication.