Phylogeny of Leafhopper Subgenus Errhomus (Erronus) (Hemiptera: Cicadellidae) Based on Mitochondrial DNA Sequences

The Nearctic leafhopper genus Errhomus Oman (Hemiptera: Cicadellidae) exhibits high host-plant selectivity and female brachyptery, which may limit gene ßow. Two subgenera, Errhomus (Errhomus) and Errhomus (Erronus), are recognized based on morphological and behavioral differences.WeusedmitochondrialDNA sequencing to elucidate the phylogenetic relationships amongmembers of the subgenus Errhomus (Erronus). Portions of the NADH dehydrogenase subunit 1 (ND1) and the leucine (CUN) transferRNA(tRNA-Leu) geneswere sequenced andwere analyzed with parsimony and maximum likelihood. Our results generally veriÞed the Þndings of Hamilton and Zack (1999); however, both optimality criteria revealed a paraphyleticErrhomus (Erronus).Errhomus (Erronus) calvus does not seem to be a member of the subgenus Errhomus (Erronus) but seems to be more closely alignedwith the subgenusErrhomus (Errhomus).We tested two a priori null hypotheses: 1) that the phylogeny estimated from the molecular data matched a previous phylogeny based on morphology and biogeography from Hamilton and Zack (1999) and 2) that diagnostic characters of the male genitalia (serrated aedeagal processes and triangular aedeagal shaft tip) were synapomorphies thatdeÞnedmajor clades.Werejected thesehypotheseswithbothBayesian tests andparametric bootstraps.