Heterocerus tenuis, Miller, 1988

King, Jonas G. & Lago, Paul K., 2012, The variegated mud-loving beetles (Coleoptera: Heteroceridae) of Mississippi and Alabama, with discussion and keys to the species occurring in the southeastern United States, Insecta Mundi 2012 (275), pp. 1-53 : 11

Male genitalia relatively expanded with pointed projections at the anterior end of the lateral arms ( Fig. 49 ). Known only from Florida and Ontario ........................... 16. H. tenuis Miller

18(12). Elytral markings longitudinally elongated so that the basal series contacts the anterior elytral border near the scutellum ( Fig. 31 ); hypermandibulate males unknown. Essentially Holarctic, common north of 40 o N, recorded in the Southeast only from Florida ........................................ ..................................................................................................... EL H. fenestratus (Thunberg)

— Elytral markings with two to three only slightly elongated or lunate spots in each series; marginal spot often connecting to a pale lateral margin (as in Fig. 1) ................................................... 19

19(18). Median plate broad at connection to phallobase, nearly parallel sided throughout length ( Fig. 40, 42 ) .................................................................................................................................................... 20

— Median plate distinctly and abruptly tapered to a rounded point at connection to phallobase ( Fig. 41, 43 ) ............................................................................................................................................. 21

Figures

Figures 45-53. Male genitalia of southeastern species. The ventral view is shown unless otherwise stated. 45-50) Heterocerus species in the undulatus group. 45) H. undatus. 46) H. collaris. 47) H. texanus; left - ventral view, right - lateral view. 48) H. schwarzi; left - ventral view, right - lateral view. 49) H. tenuis. 50) H. selanderi. 51-53) Augyles and Tropicus species. Figures 52-53 are at roughly 2x relative scale of prior genitalia. 51) Augyles auromicans. 52) Tropicus nigrellus; left - dorsal view, center - ventral view, right - lateral view. 53) Tropicus pusillus; left - dorsal view, right - ventral view.

Figures 30-31. Habiti of two widespread species reported to occur in the southeastern USA. 30) Augyles auromicans. 31) Heterocerus fenestratus. Scale line = 1mm.

Figures 32-44. Male genitalia of southeastern Heterocerus species. The ventral view is shown unless otherwise stated. 32-39) Species that lack post-mesocoxal lines. 32) H. fatuus. 33) H. glicki. 34) H. intermuralis. 35) H. angustatus; left - ventral view, right - dorsal view. 36) H. longilobulus. 37) H. pallidus; left - ventral view, right - dorsal view. 38) H. gnatho; left - ventral view, right - dorsal view. 39) H. sandersoni; left - ventral view, center - dorsal view, left - lateral view. 40-44) Species with post-mesocoxal lines. 40) H. sinuosus; left - dorsal view, right - ventral aspect. 41) H. mollinus. 42) H. insolens; left - dorsal view, right - ventral aspect. 43) H. parrotus. 44) H. brunneus.