2026/04/24 by Y Miles Zhang, Justin Meröndun, Renee L Corpuz +3 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Hymenoptera taxonomy and phylogeny #Genomics and Phylogenetic Studies #Phytoplasmas and Hemiptera pathogens
paper · doi:10.1093/g3journal/jkag105
The Erythrina gall wasp, Quadrastichus erythrinae, is an invasive gall-inducing chalcidoid wasp and a major pest of the endemic wiliwili tree (Erythrina sandwicensis) in Hawai'i. As a foundation for associated research, we generated a chromosome-level genome assembly from a wild-collected female measuring <2 mm. The final assembly consists of 5 scaffolds representing the 5 autosomes totaling 399 Mb (N50 = 75.6 Mb) and 1 unplaced 16 kb contig. BUSCO analysis recovers 91.1% of conserved Hymenoptera orthologs, representing the first chromosome-scale genome for the genus Quadrastichus. Comparative genomic analyses reveal syntenic conservation across Hymenoptera despite deep evolutionary divergence, with strongest collinearity to the chalcidoid Nasonia vitripennis. Genome size variation is largely explained by repeat content, and Q. erythrinae exhibits high proportions of unclassified transposable elements similar to the cynipid gall inducer. We also assembled a complete genome of its endosymbiont, Wolbachia pipientis. Together, these genomic resources provide a foundation for comparative, evolutionary, and applied research aimed at managing this invasive pest.