Continent-wide population genomic structure and phylogeography of North America's most destructive conifer defoliator, the spruce budworm ().

The spruce budworm, , is presumed to be panmictic across vast regions of North America. We examined the extent of panmixia by genotyping 3,650 single nucleotide polymorphism (SNP) loci in 1975 individuals from 128 collections across the continent. We found three spatially structured subpopulations: Western (Alaska, Yukon), Central (southeastern Yukon to the Manitoba-Ontario border), and Eastern (Manitoba-Ontario border to the Atlantic).