Molecular phylogeny and multispecific aggregation behavior of North American brachinus (Weber) (Coleoptera: Carabidae: Brachininae)

The phylogeny of North American Brachinus species is inferred from mitochondrial (COI) and nuclear (CAD) gene sequences and compared to a published phylogeny of the genus based on morphological characters.  To explore multispecific aggregation behavior of Brachinus, several whole aggregations were collected and analyzed for species content, using the molecular phylogeny to confirm species boundaries.   Behavioral experiments in the laboratory tested aggregation responses of B. elongatulus (Chaudoir) to conspecifics versus individuals of another Brachinus species, B. hirsutus (Bates), and another sympatric carabid, Chlaenius cumatilis LeConte.