Berosini

Short, Andrew Edward Z. & Torres, Phillip J., 2006, Review of the Hemiosus Sharp and Derallus Sharp of North America, Central America, and the Caribbean (Coleoptera: Hydrophilidae: Berosini), Zootaxa 1369, pp. 1-17 : 3

Key to the genera of New World Berosini

1. Dorsum entirely black; form nearly subglobular. Metaventrite with median longitudinal carina (e.g. Figs. 10–11 ) .................................................................... Derallus Sharp

- Dorsum at least partially testaceous, often with black maculae and markings on the pronotum and elytra; form convex to strongly convex, but never subglobular. Metaventrite without longitudinal carina ...................................................................... 2

2 Pubescence of femora consisting of very short and extremely dense setae. Mesosternal process never narrowly laminar. Male protarsi with five segments ......................... ............................................................................................................... Hemiosus Sharp

- Pubescence of femora with setae longer and not extremely dense. Mesosternal process usually but not always laminar. Male protarsi with four segments ......... Berosus Leach

Figures

FIGURES 10 – 11. Ventral view of the metasternum of Derallus. 10: D. rudis Sharp; 11: D. angustus Sharp. Scale bar 0.2 mm.