Genomes of two invasive species (hemlock woolly adelgid and pineapple gall adelgid) enable characterization of nicotinic acetylcholine receptors.

Two invasive hemipteran adelgids cause widespread damage to North American conifers. (the hemlock woolly adelgid) has decimated and (the Eastern and Carolina hemlocks, respectively). was introduced from East Asia and reproduces parthenogenetically in North America, where it can kill trees rapidly. introduced from Europe, makes "pineapple" galls on several North American spruce species, and weakens trees, increasing their susceptibility to other stresses. Broad-spectrum insecticides that are often used to control adelgid populations can have off-target impacts on beneficial insects and the development of more selective chemical treatments could improve control methods and minimize ecological damage. Whole genome sequencing was performed on both species to aid in development of targeted pest control solutions and improve species conservation. The assembled and genomes are 220.75 Mbp and 253.16 Mbp, respectively, each consisting of nine chromosomes and both genomes are over 96% complete based on BUSCO assessment. Genome annotation identified 11,424 and 14,118 protein-coding genes in , respectively. Comparative analysis across 29 Hemipteran species and 14 arthropod outgroups identified 31,666 putative gene families. Gene family expansions in included ABC transporters and carboxypeptidases involved in carbohydrate metabolism, while both species showed contractions in core histone families and oxidoreductase pathways. Gene family expansions in highlighted families associated with the regulation of cell differentiation and development (, SMN; JHAMT) as well as those that may be involved in the suppression of plant immunity (, CLIPD; , ERAP1). Among the analyzed gene families, Nicotinic acetylcholine receptors (nAChRs) maintained consistent copy numbers and structural features across species, a finding particularly relevant given their role as targets for current forestry management insecticides. Detailed phylogenetic analysis of nAChR subunits across adelgids and other ecologically important insects revealed remarkable conservation in both sequence composition and predicted structural features, providing crucial insights for the development of more selective pest control strategies.