A molecular phylogeny of the Machaerotidae, the tube-making spittlebug (Hemiptera: Cercopoidea)

Machaerotidae, with approximately 115 described species in 29 genera, is one of the five spittlebug families within the superfamily Cercopoidea (Hemiptera: Auchenorrhyncha: Cicadomorpha) (along with Cercopidae, Aphrophoridae, Epipygidae, and Clastopteridae). While spittlebugs are best known for the frothy mass produced by their nymphs, species of Machaerotidae produce hard, calcareous tubes in which they dwell. There has been little systematic research on the family, with Maa's (1963) “A Review of the Machaerotidae” being the most comprehensive analysis to date, in which a generic level phylogeny was proposed based on various morphological characters. This, however, was not tested by quantitative analysis. Recently, the family-level status of Machaerotidae was challenged by Hamilton (2001), who proposed that this group be reclassified, as Machaerotinae, within a redefined Clastopteridae due to similarities in antennal characters and hind-wing venation. Conversely, in a molecular phylogenetic investigation of family-level relationships within Cercopoidea, Cryan and Svenson (2010) concluded that Machaerotidae is a monophyletic lineage, distinct and separate from Clastopteridae, arising from the most basal node of the cercopoid phylogeny as the sister-group to all other spittlebugs, but their placement received low statistical support. The present study investigates the phylogeny of the family Machaerotidae with the specific aims of: (1) testing the monophyly of, and relationships among, the currently recognized subfamilies and tribes; (2) evaluating the relationship between Machaerotidae and Clastopteridae with particular regard to the revised classification proposed by Hamilton (2001); and (3) testing the phylogenetic placement of genera identified by Hamilton (2001) as potential intermediates between Machaerotidae and Clastopteridae.