Litter bugs exposed: phylogenetic relationships of Dipsocoromorpha (Hemiptera: Heteroptera) based on molecular data

摘要

Species in the heteropteran infraorder Dipsocoromorpha, or litter bugs, are small, cryptic, stunningly diverse and understudied. In addition to the vast amount of species discovery and morphological exploration that remain to be done in this group, phylogenetic relationships within the litter bugs are poorly understood. A phylogenetic framework will make Dipsocoromorpha more accessible for systematic studies at all levels and is therefore a first step towards a comprehensive treatment of the group. Using a molecular dataset (87 taxa of Hemiptera including 35 Dipsocoromorpha; two genes) and maximum likelihood and parsimony methods, we here aim to test, for the first time using cladistic methods and a comprehensive dataset, relationships within Dipsocoromorpha. We investigate if Dipsocoromorpha are monophyletic, shed light on the relationships among the three families included in this analysis, and study relationships within the largest family of Dipsocoromorpha, the Schizopteridae. Based on this dataset, we find that the monophyly of Dipsocoromorpha is strongly supported in all analyses and that Ceratocombidae and Dipsocoridae together are recovered as the sister group of Schizopteridae. Within Schizopteridae, Hypselosomatinae are treated as the sister group to a clade formed by the monophyletic Ogeriinae and monophyletic Schizopterinae. Within Schizopterinae, there is evidence for the monophyly of the Corixidea genus group, and we present additional infra-generic and genus-level hypotheses. We discuss these hypotheses in the light of current classifications and hypotheses on relationships and as the first contribution towards revealing the phylogenetic relationships of a remarkable and neglected clade of true bugs.