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

Abstract

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 explora tion 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 stud ies 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 dade 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 contribu tion towards revealing the phylogenetic relationships of a remarkable and neglected clade of true bugs.

Introduction to True Bugs (Heteroptera) of the Neotropics

“…The fauna in the neotropics is greatly diverse and poorly studied (Grazia and Fernandes 2012 ). Weirauch and Štys ( 2014 ) performed a phylogenetic analysis of this infraorder supporting its monophyly.…”

The Minute Litter Bugs (Dipsocoromorpha)

“…However, Štys also pointed out that the monophyly of the group is far from being well established (Štys 2014 ;Weirauch and Schuh 2011 ). Molecular data were virtually unavailable until recently (Wheeler et al 1993 ;Schuh et al 2009 ) and are still scarce after the fi rst published molecular study focusing on relationships among the three larger families of Dipsocoromorpha (Weirauch and Štys 2014 ). Weirauch and Štys ( 2014 ), based on molecular cladistic analyses of 87 taxa (35 of them Dipsocoromorpha) and two gene regions, found strong support for the monophyly of Dipsocoromorpha and the three included families.…”

“…Molecular data were virtually unavailable until recently (Wheeler et al 1993 ;Schuh et al 2009 ) and are still scarce after the fi rst published molecular study focusing on relationships among the three larger families of Dipsocoromorpha (Weirauch and Štys 2014 ). Weirauch and Štys ( 2014 ), based on molecular cladistic analyses of 87 taxa (35 of them Dipsocoromorpha) and two gene regions, found strong support for the monophyly of Dipsocoromorpha and the three included families. The three recognized subfamilies of Schizopteridae were included in the analyses: Hypselosomatinae were supported as the sister taxon to a clade comprising the Ogeriinae and Schizopterinae.…”

“…All three recognized subfamilies of Schizopteridae, the Hypselosomatinae, Ogeriinae, and Schizopterinae, occur in the Neotropical region, although Schizopterinae contribute the greatest proportion of the genus-and species-level diversity (Emsley 1969 ;Weirauch and Štys 2014 ). The family comprises about 48 genera and more than 200 described species (Weirauch and Štys 2014 ).…”

“…The family comprises about 48 genera and more than 200 described species (Weirauch and Štys 2014 ). Nineteen of these genera occur in and are restricted to the New World, and all except four are only documented from the Neotropical region.…”