NON-MONOPHYLY OF AUCHENORRHYNCHA (HOMOPTERA), BASED UPON 18S RDNA PHYLOGENY - ECO-EVOLUTIONARY AND CLADISTIC IMPLICATIONS WITHIN PRE-HETEROPTERODEA HEMIPTERA (SL) AND A PROPOSAL FOR NEW MONOPHYLETIC SUBORDERS

Parsimony-based phylogenetic analyses of full 18S rRNA genes (18S rDNA ) were conducted to determine the basal clade topology of Hemiptera. T he single most parsimonious topology, which attenuated homoplasy and r etained only the most conservative base sites, showed: (a) Sternorrhyn cha and Euhemiptera are sister-clades; (b) Cicadomorpha (composed of C icadidae and sister-clade Cercopidae + Membracidae) is sister-clade to the remaining Euhemiptera; and (c) Fulgoromorpha is sister-clade to H eteropterodea (Coleorhyncha + Heteroptera). Supportive morphological s ynapomorphies for the 18S rDNA topology are listed. Less parsimonious, but competitive topologies indicate association of Heteroptera with e xtant Cicadomorpha. Thus, Auchenorrhyncha is unlikely (< 10%) to be mo nophyletic, as previously assumed, and its morphological synapomorphie s (tymbal acoustic systems, aristoid antennae, ScP + R vien fusion) ar e homoplasious; the misinterpretation, selection, and convergence of t hese traits is discussed. Current paleontological assessments of the b asal Hemiptera are reviewed and also suggest non-monophyly for Aucheno rrhyncha. A Lower Cretaceous fossil, Megaleurodes megocellata Hamilton , previously assigned to Aleyrodoidea: Boreoscytidae, is tentatively r eassigned to fossil superfamily Fulgoridioidea of Fulgoromorpha. Use o f paraphyletic Auchenorrhyncha should be abandoned as a hemipteran sub order; instead recognition of the four monophyletic basal clades of He miptera as its suborders is appropriate. Three new suborder names are proposed because of potential confusions or varying definitions (discu ssed) involving existing names: Clypeorrhyncha (= extant, monophyletic Cicadomorpha), Archaeorrhyncha (= Fulgoromorpha), and Prosorrhyncha ( = Heteropterodea, as clade Coleorhyncha + Heteroptera); Sternorrhyncha is retained. Clade name Neohemiptera is proposed for the clade Fulgor omorpha + Heteropterodea. An eco-evolutionary scenario for cladogenesi s among the basal hemipteran clades is presented. Evidence indicates a saltational, punctuated equilibrium mode of evolution occurred among the clades during, or near, the Permian.