UC Riverside

Assassin bugs (Heteroptera: Reduviidae) comprise the second largest family (~7,000 spp., 24 subfamilies) of true bugs. Among the most common and diverse of these are ambush bugs of the genus Phymata Latreille, 1802 (Phymatinae: Phymatini), and the bee assassins, Apiomerus Hahn, 1831 (Harpactorinae: Apiomerini). Both clades act as natural enemies to a wide variety of flower-associated arthropods and possess powerful raptorial forelegs and venomous saliva that facilitate capture of large, fastmoving prey. Depending on circumstances, some of these reduviids might serve as helpful biological control agents while others may hinder efforts to control pests by engaging in intraguild predation or consume pollinators. Sexual dimorphism, intraspecific polychromatism, and subtle differences between species make taxon identification among Phymata and Apiomerus difficult. While these reduviids make attractive subjects for investigating evolutionary, ecological, and behavioral questions, research on these insects is impeded by outdated taxonomy and a paucity of detailed phylogenetic analyses. This dissertation provides a clearer understanding of phymatine and harpactorine evolutionary history, biodiversity, and ecology by: (1) revealing the phylogeny of Phymatinae and testing biogeographical hypotheses and ages of divergence to inform classification, (2) conducting integrative species delimitation to delineate the polymorphic and sexually dimorphic species of North American Phymata, (3) taxonomically revising Phymata of the Nearctic erosa species group, (4) reclassifying Apiomerus of the maya species group, and (5) investigating the broad diet range of ambush bugs through molecular gut content analysis.