title: Evolutionary origin of whiteflies (Hemiptera: Sternorrhyncha: Aleyrodidae) inferred from 18S rDNA sequences.
abstract: Phylogenetic analysis of 18S rDNA nucleotide sequences of hemipteran exemplars shows Sternorrhyncha (psyllids, whiteflies, aphids and scales) is monophyletic and forms a sister group to all other hemipterans (Euhemiptera). Whiteflies form a sister group to all other Sternorrhyncha. Primary structures of 18S rDNAs of all sternorrhynchans are exceptionally long (approximately 2200 to approximately 2500 bp) due to internal expansions. These expansions are a synapomorphy of Sternorrhyncha; other hemipterans possess shorter 18S rDNAs (approximately 1900 to approximately 1925 bp). The 18S rDNA of whiteflies is the longest recorded to date and has a base substitution rate of approximately 3 times greater than Euhemiptera taxa examined. The relevance of these findings to the fossil record, feeding strategies, reproductive biologies, and geoclimatic distribution is discussed.
authors.affiliation: WRRC, USDA-ARS, Albany, California 94710-1100.
authors.forename: B C
authors.initials: BC
authors.lastname: Campbell
authors.forename: J D
authors.initials: JD
authors.lastname: Steffen-Campbell
authors.forename: R J
authors.initials: RJ
authors.lastname: Gill
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D001517:Coleoptera / Q000235:genetics; D016384:Consensus Sequence; D017124:Conserved Sequence; D004275:DNA, Ribosomal / Q000235:genetics*; D005580:Fossils; D006430:Hemiptera / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D004275:DNA, Ribosomal