Molecular systematics and evolution of the Ptinidae (Coleoptera: Bostrichoidea) and related families: an update

The spider beetles or Ptinidae, sensu stricto, are a cosmopolitan, ecologically diverse, but poorly known group of beetles (Coleoptera: Bostrichoidea) that are typically not commonly collected.  Phylogenetic studies of the bostrichoids (Bell and Philips 2012) were expanded by continuing to examine DNA sequence data from two mitochondrial genes (CO1 and 16S) and one nuclear ribosomal gene (28S), using outgroups from the Dermestidae.  Topologies varied depending upon which gene was used and whether the data was analyzed by either parsimony or Bayesian methods.  The nuclear gene, 28S, usually supported basal relationships while the two mitochondrial genes, 16S and CO1, generally supported relationships near the tips of the phylogeny.

In all analyses, the Ptinidae, the Anobiidae, and the Bostrichidae are strongly supported as monophyletic.  In the total evidence approach, the Bostrichidae is basal while in the bayesian tree the Ptinidae is basal and paraphyletic without including the Anobiidae and Bostrichidae.  Proposed subfamily and tribal classifications are usually not monophyletic when tested.  Our studies are on-going in order to determine the most accurate relationships within the Bostrichoidea to further clarify the evolution of the group and to eventually propose a stable and natural classification.