Application of DNA barcoding to the identification of Hymenoptera parasitoids from the soybean aphid （Aphis glycines） in China

Aphis glycines Matsumura is an important pest of soybean in Asia and North America. Hymenoptera parasitoids play a key role in the control of the soybean aphid. Thecorrect identification of parasitoids is a critical step that precedes the assessment of their potential biological control agents. Accurate identification of the majority of the speciesattacking the soybean aphid often requires elaborate specimen preparation and expert taxonomic knowledge. In this study, we facilitated the identification of soybean aphidparasitoids by applying a DNA barcoding approach following a preliminary morphological identification. We generated DNA sequence data from the mitochondrial COI gene andthe D2 region of 28S rDNA to assess the genetic variation within and between parasitoid species emerging from the soybean aphid in China. Fifteen Hymenoptera parasitoid speciesbelonging to 10 genera of five families were identified with little intra-specific variation （0.09% ± 0.06% for 28S and 0.36% ± 0. 18% for COI） and large inter-specific divergence（30.46% ± 3.42% for 28S and 20.4% ± 1.20% for COI）.

Testing the systematic status of Homalictus and Rostrohalictus with weakened cross-vein groups within Halictini(Hymenoptera:Halictidae)using low-coverage whole-genome sequencing

The halictid genus Lasioglossum,as one of the most species-rich bee groups with persistently contentious subgeneric boundaries,is one of the most challenging bee groups from a systematic standpoint.An enduring question is the relationship of La-sioglossum and Homalictus,whether all halictine bees with weakened distal wing ve-nation comprise one or multiple genera.Here,we analyzed the phylogenetic relation-ships among the subgroups within Lasioglossum s.l.based on thousands of single-copy orthologs and ultraconserved elements,which were extracted from 23 newly sequenced low-coverage whole genomes alongside a published genome(22 ingroups plus 2 out-groups).Both marker sets provided consistent results across maximum likelihood and coalescent-based species tree approaches.The phylogenetic and topology test results show that the Lasioglossum and Hemihalictus series are reciprocally monophyletic and Homa-lictus and Rostrohalictus are valid subgenera of Lasioglossum.Consequently,we lower Homalictus to subgenus status within Lasioglossum again,and we also raise Rostrohalic-tus to subgenus status from its prior synonymy with subgenus Hemihalictus.Lasioglossum przewalskyi is also transferred to the subgenus Hemihalictus.Ultimately,we redefine La-sioglossum to include all halictine bees with weakened distal wing venation.