Assessment of the Aphodius fimetarius-Aphodius pedellus (Coleoptera: Scarabaeidae) species complex in Canada

Aphodius fimetarius (Linnaeus, 1758) (Coleoptera: Scarabaeidae: Aphodiinae: Aphodiini) sensu lato is a taxon of probable European origin common in cattle dung across North America. This species has recently been recognised as a species complex composed of A. fimetarius and Aphodius pedellus (De Geer, 1774), with overlapping distributions in North America. A previous report that only A. pedellus is present in Canada was based on examination of specimens almost solely from the United States of America. In the present study, we examined the morphology of specimens (n = 2091) from localities across Canada. In combination with DNA barcoding, our results confirm that only A. pedellus is present in Canada. Results of similarity analysis confirm reduced genetic diversity among North American specimens of A. pedellus, consistent with the hypothesis that this species was introduced onto the continent during European settlement.