Phylogenetic observations on the elderberry-boring longhorn beetle, Desmocerus Dejean (Cerambycidae: Lepturinae)

The North American longhorn beetle Desmocerus is an anomaly in its subfamily Lepturinae due to its extreme morphology, apparent aposematism, unique feeding and pheromone behaviors, and its close obligate relationship with a living host plant, Sambucus (elderberry).  In addition to the wealth of evolutionary and physiological questions surrounding the genus, another motivation for elaborating the phylogeny of Desmocerus is related to its complex biogeography in the west coast, where the distributions of certain cold-adapted, high altitude lineages in the D. aureipennis species-complex have likely traced patterns of the region's periodic glaciations during the Pleistocene. In this talk I present a preliminary phylogenetic analysis of Desmocerus using the mitochondrial gene CO-1 obtained from 24 localities, primarily in the Pacific Northwest.  Additional morphological evidence from the hindwings and male genitalia support the molecular phylogeny, and reveal a more nuanced view of the lineages within the aureipennis species-complex. At least one new subspecies is recognized.