The Higher-Level Phylogeny of Cerambycidae Sensu Lato and New Insights into the Structure of Tufted Antennae

Cerambycidae (longhorned beetles) is a species-rich family of mostly wood-feeding beetles containing nearly 35,000 species. It belongs to the superfamily Chrysomeloidea and includes many ecologically and economically significant species. The higher-level phylogeny of Cerambycidae has never been robustly reconstructed using molecular phylogenetic data or a representative sample of higher taxa, and its internal relationships and evolutionary history remain the subjects of ongoing debate. As such, the systematics and evolution of Chrysomeloidea were reviewed herein to provide context for reconstructing the phylogeny of longhorned beetles using molecular phylogenetic data/analyses. The first higher-level molecular phylogeny of Cerambycidae was reconstructed via analysis of phylogenomic data from 522 single copy nuclear genes, generated via anchored hybrid enrichment. The taxon sample included exemplars of all families and 23/30 subfamilies of superfamily Chrysomeloidea (longhorned beetles, leaf beetles, and their relatives). The inferred phylogenetic hypotheses revealed a monophyletic Cerambycidae sensu stricto in all but one analysis, and a polyphyletic Cerambycidae sensu lato. When monophyletic, Cerambycidae sensu stricto was sister to the family Disteniidae. Relationships among the subfamilies of Cerambycidae sensu stricto were also recovered with strong statistical support, except for Cerambycinae, which was rendered paraphyletic by Dorcasomus (Dorcasominae) in the nucleotide (but not amino acid) trees. Most other chrysomeloid families represented by more than one terminal taxon – Chrysomelidae, Disteniidae, Vesperidae, and Orsodacnidae – were monophyletic, but Megalopodidae was rendered paraphyletic by Cheloderus (Oxypeltidae). These results corroborate relationships previously inferred from morphological data, while also reporting several novel relationships. The present work thus provides a robust framework for future, more deeply taxon-sampled, phylogenetic and evolutionary studies of the families and subfamilies of Cerambycidae sensu lato and other Chrysomeloidea. In addition to the phylogenetics of Cerambycidae, I was also interested in the evolution of a curious morphological alteration in the group. Some cerambycids have evolved setal tufts resembling bottle brushes on their antennae. The function of these interesting appendages remains unknown and their structures have not been examined using scanning electron microscopy. As such, the sensilla present on the tufted antennae of the cerambycid species Cirrhicera sallei Thomson (subfamily Lamiinae) were investigated using scanning electron microscopy. This work serves as a first step towards better understanding the function and evolution of these unusual antennal features in cerambycids