title: DNA barcodes to identify species and explore diversity in the Adelgidae (Insecta: Hemiptera: Aphidoidea).
abstract: The Adelgidae are relatively small, cryptic insects, exhibiting complex life cycles with parthenogenetic reproduction. Due to these characteristics, the taxonomy of the group is problematic. Here, we test the effectiveness of the standard 658-bp barcode fragment from the 5'-end of the mitochondrial cytochrome c oxidase 1 gene (COI) in differentiating among 17 species of Adelgidae, in associating life-cycle stages, and in assessing patterns of geographical variation in selected species. Species of Adelgidae are well-differentiated by DNA barcodes, enabling the identification of different morphological forms, immature stages and individuals on different hosts and at different periods of the life cycle. DNA barcodes have uncovered cryptic diversity within taxa and, in other cases, a lack of sequence divergence in species pairs previously separated by life-cycle characteristics, indicating a need for further taxonomic analysis.
authors.affiliation: National Environmental Health Program, Invertebrate Biodiversity, Agriculture and Agri-Food Canada, K. W. Neatby Bldg, 960 Carling Avenue, Ottawa, Ontario, Canada K1A 0C6, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA, Department of Entomology, Michigan State University, East Lansing, MI 48824, USA, Northern Research Center, United States Department of Agriculture, Forest Service, Hamden, CT 06514, USA.
authors.forename: R G
authors.initials: RG
authors.lastname: Foottit
authors.forename: H E L
authors.initials: HE
authors.lastname: Maw
authors.forename: N P
authors.initials: NP
authors.lastname: Havill
authors.forename: R G
authors.initials: RG
authors.lastname: Ahern
authors.forename: M E
authors.initials: ME
authors.lastname: Montgomery