Genetic Structure and Colonization of North America by (Fabricius 1775) (Lepidoptera: Depressariidae) over 15 Years; Contrasts with Westward Expansion of (Goeze, 1783) over 160 Years.

, the purple carrot seed moth, is a Eurasian species first reported in North America in 2008 and currently undergoing range expansion. This invasion follows that of its Eurasion congener (parsnip webworm), first documented in North America 160 years ago. Unlike , which utilizes hostplants across multiple tribes of Apiaceae, is a "superspecialist" effectively restricted in its native and non-indigenous ranges to two closely related apiaceous genera. We investigated the genetic structure of populations across latitudinal and longitudinal gradients in the eastern United States by constructing COI haplotype networks and then comparing these with haplotype networks constructed from available COI sequence data from contemporary European populations and from European and North American populations. Haplotype data revealed higher genetic diversity in , indicating high dispersal capacity, multiple introductions, and/or a genetically diverse founding population. Museum and literature records of date back to 1862 and indicate that range expansion to the West Coast required more than 50 years. Higher levels of genetic diversity observed in compared to its congener may indicate a greater propensity for dispersal, colonization and establishment in its non-indigenous range.