Integrated Venom Gland Transcriptomic and Venom Proteomic Analyses of the Digger Wasp Cerceris japonica

Digger wasps are solitary apoid wasps that excavate ground nests and use venom to paralyze insect prey. Recent phylogenetic analyses suggest that digger wasps belong to an ancient lineage of aculeate Hymenoptera and share an evolutionary ancestry with other venomous hymenopterans, including bees and ants. Although the venoms of ants, bees, and social wasps have been extensively studied, those of digger wasps remain poorly characterized in terms of their composition, molecular diversity, and biological activity. In this study, we investigated the venom of the digger wasp Cerceris japonica using integrated transcriptomic and proteomic analyses. We identified 19 toxin-like proteins and peptides, 14 non-toxin-associated components, and 11 novel peptides and proteins with no detectable similarity to known peptides and proteins. Among these, peptide Cj 2 exhibited insecticidal activity but showed no antimicrobial, hemolytic, or nicotinic acetylcholine receptor-modulating activities. These findings provide new insights into the molecular diversity and biological activities of digger wasp venom, expand our understanding of venom evolution in venomous hymenopterans, and serve as a framework for elucidating the conserved and lineage-specific features of hymenopteran venoms.