Genomic landscape and genetic manipulation of an ectoparasitoid wasp, Gregopimpla kuwanae

Parasitoid wasps are important biological control resources, yet their genetic manipulation has long been constrained by small body size and parasitization behavior, limiting their broader application in pest management. Here we report a chromosome-level genome assembly of the ectoparasitoid Gregopimpla kuwanae (322.87 Mb, 24 chromosomes), a relatively large species that parasitizes various lepidopteran pests. In the first part of this study, we established a foundational genomic resource and experimental platform by producing a high-quality genome and demonstrating the feasibility of functional genetics: RNA interference successfully silenced the cinnabar gene, while CRISPR/Cas9 editing generated vestigial knockout mutants, thus establishing G. kuwanae as a tractable system for gene manipulation. In the second part, we applied comparative genomics to identify lineage-specific gene-family expansions linked to parasitism, including venom-related genes, immune suppression factors, and detoxification enzymes (cytochrome P450s and UDP-glucosyltransferases), and we identified eight HGT candidates; one candidate (JSFChr12G01362) showed pre-feeding expression in females and caused increased adult mortality upon RNAi. Our study provides both the means and the candidates for mechanistic dissection of parasitoid adaptations, laying a foundation for the broader application of parasitoid wasps in sustainable biocontrol programs.