UC Riverside

Dipsocoromorpha, or the minute litter bugs, are a poorly studied and minuscule group of true bugs (Hemiptera: Heteroptera) with uncertain phylogenetic position, often bizarre morphology, and substantial undescribed biodiversity. A combination of taxonomic revisions, comparative morphological studies, and phylogenetic analyses based on both morphological and molecular data is employed to advance our knowledge of the group. The first chapter taxonomically revises the New World genus Chinannus and describes 26 new species. The second chapter develops and tests a cost-efficient DNA sequencing method for archival specimens. The third chapter uses and refines this method to conduct a comprehensive phylogenetic analysis of a very diverse group of dipsocoromorphans, the Corixidea genus group. The fourth chapter taxonomically revises the genus Voragocoris that belongs to the Corixidea genus group, building on the phylogeny inferred in chapter three, and describing seven new species. The fifth chapter conducts a comparative study of abdominal morphology in Dipsocoromorpha, and both standardizes the terminology and proposes primary homology hypotheses, that could be used for a phylogenetic reconstruction. The sixth, and last, chapter presents a comprehensive phylogenetic analysis of Dipsocoromorpha based on both morphological and molecular data.