Cyrtusa, Erichson, 1842

Peck, Stewart B. & Cook, Joyce, 2013, Systematics and distributions of the genera Cyrtusa Erichson, Ecarinosphaerula Hatch, Isoplastus Horn, Liocyrtusa Daffner, Lionothus Brown, and Zeadolopus Broun of the United States and Canada (Coleoptera: Leiodidae: Leiodinae: Leiodini), Insecta Mundi 2013 (310), pp. 1-32 : 3

Key to the North American “ Cyrtusa ” and “ Leiodes ” genus-groups and their genera in the continental United States and Canada

1. Mesosternum vertical between mesocoxae; the “ Cyrtusa genus group” ..................................... 2

– Mesosternum oblique between mesocoxae; the “ Leiodes genus group” ...................................... 7

2(1). Antenna with 11 antennomeres, with interrupted 5-antennomere club, antennomere 8 narrow and disk-shaped .......................................................................................................................... 3

– Antenna with 10 antennomeres, with compact 3- or 4-antennomere club ................................. 5

3(2). Mesosternum with a median carina; each mandible with a single median tooth........................ ...................................................................................................................... Anogdus LeConte

– Mesosternum not carinate; left mandible may have a small tooth, right mandible edentate... 4

4(3). Underside of head without antennal grooves; anterior margin of clypeus straight or evenly curved; both mandibles lack prominent teeth; male mesotibia with process on inner apical margin ........................................................................................................ Liocyrtusa Daffner

– Underside of head usually with antennal grooves; anterior margin of clypeus clearly sinuous; left mandible in anterior third usually with one or two small teeth; male mesotibia without process on inner apical margin .................................................................... Lionothus Brown

5(2). Tibiae narrow; metatibia with spines on ventral side but not on outer margin; right mandible in anterior third with blunt tooth, left mandible edentate ........................ Cyrtusa Erichson

– Tibiae widened, shovel-like; outer margin of metatibia strongly spined; left mandible with large tooth at basal third, right mandible edentate........................................................................... 6

6(5). Antennal club with 4 antennomeres ............................................................. Zeadolopus Broun

– Antennal club with 3 antennomeres ................................................................. Isoplastus Horn

7(1). Mesosternum with a median longitudinal carina ........................................... Leiodes Latreille

– Mesosternum unmodified, not carinate ............................................ Ecarinosphaerula Hatch