Bembidion, Latreille, 1802

Maddison, David R., 2023, A New Subgenus of Bembidion Latreille from México and Guatemala, with Descriptions of Two New Species (Coleoptera: Carabidae), Proceedings of the California Academy of Sciences 67 (19), pp. 433-450 : 443

Key to adults of species of Bembidion subgenus Geocosmius

1. Elytra with evident microsculpture............................................. 2

— Elytra without evident microsculpture................................ nahuala group

2. Entire dorsal surface with evident microsculpture, including on the top of the head and disc of pronotum; throughout the disc of the pronotum there are clearly and completely edged sculpticells. Elytral microsculpture more transverse ( Fig. 6A ). All striae deep in anterior quarter of the elytra, with intervals notably convex in this region. Eyes of normal size for Bembidion ( Fig. 1D ).............................................. Bembidion franiae Erwin

— Dorsal surface of head shiny, without microsculpture, at least at center; pronotal disc shiny, without clear microsculpture. Elytral microsculpture more or less isodiametric ( Fig. 6B ). Lateral striae absent or nearly so, even in anterior region of elytra. Eyes slightly less protruding than typical for Bembidion ( Fig. 1C ).................. Bembidion elescarabajo sp. nov.

Figures

FIGURE 6. Microsculpture of Geocosmius. (A) Bembidion franiae, vouch- er DNA4623, (B) B. elescarabajo, voucher V101491. Scale bar 100 µm.

FIGURE 1. Habitus of Geocosmius species. (A) Bembidion “Chiapas”, brachypterous form, voucher V101274. (B) B. “Chiapas”, fully winged form, voucher V101273. (C) B. elescarabajo, paratype, voucher V101491. (D) B. franiae, specimen UASM371160. Note: B. nahuala (not shown) is extremely similar externally to B. “Chiapas”. Scale bar 1 mm.