UC Riverside

True bugs (Hemiptera: Heteroptera) are one of the most speciose suborders with incomplete metamorphosis, with behaviors including predation on arthropods, hematophagy, mycetophagy and phytophagy, and include species that are important disease vectors, plant pests and biological control agents. However, while relationships between infraorders are largely resolved, relationships between and within superfamilies are still contested, especially within the two largest infraorders, Cimicomorpha and Pentatomomorpha. Using a combined transcriptome and genome dataset covering 74 of the 88 families we resolved relationships between superfamilies and families of Cimicomorpha and Pentatomomorpha. Species within the Emesine Complex (Heteroptera: Reduviidae: Emesinae, Visayanocorinae, Saicinae) are unique among reduviids in having a cosmopolitan distribution, lacking ocelli and fossula spongiosa, and having a close association with spiderwebs. We used a combined high-throughput and Sanger sequencing dataset (384 loci, 15 taxa; 3 loci, 207 taxa) to resolve relationships between subfamilies and tribes, and discovered rampant paraphyly among subfamilies and tribes, necessitating revisions to the classification. We used ancestral character state reconstructions for 40 morphological characters to identify diagnostic features for a revised classification. Our new classification treats Saicinae and Visayanocorinae as junior synonyms of Emesinae, synonymizes the emesine tribes Ploiariolini Van Duzee and Metapterini Stål with Emesini Amyot and Serville, and recognizes six tribes within Emesinae (Collartidini Wygodzinsky, Emesini, Leistarchini Stål, Oncerotrachelini trib. nov., Saicini Stål stat. nov., and Visayanocorini Miller stat. nov.). We then used our phylogenetic hypothesis to test whether the four cosmopolitan genera share similar dispersal patterns and found they each dispersed during the Eocene, but from and to different continents. Based on their dispersal patterns and timing, and the observation that thread-legged bugs are found in flotsam, we further hypothesize that they may have dispersed primarily via rafting. Rarely collected, Collartidini (4 genera, 14 species) are a tribe of Emesinae that have retained a number of plesiomorphic features within Emesinae. The discovery of two undescribed species from Thailand and Malaysia (Borneo) has created the need for a reassessment of genera within Collartidini. We here synonymize the fossil genus Collarhamphus and extant genera Mangabea and Stenorhamphus, provide a revised diagnosis and description of Stenorhamphus, and describe Stenorhamphus segerak, new species and S. phuphan, new species, from Malaysia (Sarawak) and Thailand, respectively.