Immigrant Tortricidae: Holarctic versus Introduced Species in North America

Simple Summary The family Tortricidae includes approximately 11,500 species of small moths, many of which are economically important pests worldwide. A large number of tortricid species have been inadvertently introduced into North America from Eurasia, and many have the potential to inflict considerable negative economic and ecological impacts. Because native species behave differently than introduced species, it is critical to distinguish between the two. Unfortunately, this can be a difficult task. In the past, many tortricids discovered in North America were assumed to be the same as their Eurasian counterparts, i.e., Holarctic. Using DNA sequence data, morphological characters, food plants, and historical records, we analyzed the origin of 151 species of Tortricidae present in North America. The results indicate that the number of Holarctic species has been overestimated by at least 20%. We also determined that the number of introduced tortricids in North America is unexpectedly high compared other families, with tortricids accounting for approximately 23-30% of the total number of moth and butterfly species introduced to North America. This suggests that introduced tortricids have a greater potential of becoming economically important pests than moths in other families, and why distinguishing Holarctic from introduced species is critical to American agriculture. In support of a comprehensive update to the checklist of the moths of North America, we attempt to determine the status of 151 species of Tortricidae present in North America that may be Holarctic, introduced, or sibling species of their European counterparts. Discovering the natural distributions of these taxa is often difficult, if not impossible, but several criteria can be applied to determine if a species that is present in both Europe and North America is natively Holarctic, introduced, or represented by different but closely related species on each continent. We use DNA barcodes (when available), morphology, host plants, and historical records (literature and museum specimens) to make these assessments and propose several taxonomic changes, as well as future areas of research. The following taxa are raised from synonymy to species status: Acleris ferrumixtana (Benander, 1934), stat. rev.; Acleris viburnana (Clemens, 1860), stat. rev.; Acleris pulverosana (Walker, 1863), stat. rev.; Acleris placidana (Robinson, 1869), stat. rev.; Lobesia spiraeae (McDunnough, 1938), stat. rev.; and Epiblema arctica Miller, 1985, stat. rev. Cydia saltitans (Westwood, 1858), stat. rev., is determined to be the valid name for the jumping bean moth, and Phiaris glaciana (Moschler, 1860), comb. n., is placed in a new genus. We determine that the number of Holarctic species has been overestimated by at least 20% in the past, and that the overall number of introduced species in North America is unexpectedly high, with Tortricidae accounting for approximately 23-30% of the total number of Lepidoptera species introduced to North America.