Elonus, Casey, 1895

Gompel, Nicolas, 2017, A review of North American Elonus species, with description of E. gruberi n. sp. (Coleoptera: Tenebrionoidea: Aderidae), Zootaxa 4338 (3), pp. 533-545 : 534-535

Key to North American Elonus Species

1. Elytra uniformly dark brown with pattern of white setae consisting of a median wavy transverse stripe, two basal patches, and an apical band ( Figure 1i )........................................................ E. nebulosus ( LeConte, 1875)

- Elytra bicolored: base entirely orange or with an orange blotch on each elytron, rest of the elytra brown to black ( Figure 1a–h ).................................................................................................... 2

2. Short elytral pubescence between punctures dense, white, uniform, distinctly visible under lateral illumination ( Figure 4e–f ) 3

- Short elytral pubescence between punctures sparser, darker, hardly visible, or limited to suture and a post-median stripe (Figure 4g –j)............................................................................................ 4

3. Elytra brown (except base), uniformly covered with long erected yellow setae ( Figure 4f ). forelegs and midlegs reddish. Male mesotibiae strongly curved ( Figure 3l )................................................. E. hesperus Werner, 1990

- Elytra black, long pale pubescence darker, only with white setae along suture ( Figure 4e ). Male mesotibiae with moderate curvature ( Figure 3n )............................................................... E. chisosensis Werner, 1992

4. Base of elytra marked with a solid, uninterrupted transverse orange stripe, only moderately narrower in scutellar region ( Figure 4c )................................................................................................. 5

- Base of elytra marked with orange patches confined to humeral callus on each side; or orange markings forming a continuous stripe but with a strong constriction in the scutellar region ( Figure 4a, b ).............................. E. gruberi n. sp.

5. Elytra with a post-median band of whitish pubescence, distinct under side illumination, composed of short recumbent setae interspersed between elytral punctation ( Figure 4h , arrows). Male genitalia much longer than in other species ( Figure 2a )................................................................................... E. basalis ( LeConte, 1855)

- Elytra without pattern of whitish pubescence................................................................ 6

6. Thorax and head half the width of elytra at their base; male mesotibiae with a kink ( Figure 3m )... E. excavatus Werner, 1992

- Thorax and head at least 60% of elytra width at their base; male mesotibiae evenly curved......... E. simplex Werner, 1992

Figures

FIGURE 1. Habitus of Elonus species in dorsal view. a, Elonus basalis (LeConte), ♂, from Wisconsin. b, Elonus gruberi n. sp., ♂ holotype, from Wisconsin. c, Elonus gruberi n. sp., ♀, from Wisconsin. d, Elonus simplex Werner, ♂, from Arizona (paratype). e, Elonus hesperus Werner, ♂, from Mississippi. f, Elonus hesperus Werner, ♀, from Mississippi. g, Elonus excavatus Werner, ♂, from Arizona (holotype). h, Elonus chisosensis Werner, ♂, from Arizona (paratype). d, Elonus nebulosus (LeConte), ♂, from Texas.

FIGURE 2. Male genitalia and antennae of Elonus species. a – g, male genitalia in dorsal view. a, Elonus basalis (LeConte), from Wisconsin; b, Elonus gruberi n. sp., ♂ holotype, from Wisconsin; c, Elonus hesperus Werner, from Mississippi; d, Elonus nebulosus (LeConte), from Texas; e, Elonus simplex Werner, from Arizona (paratype); f, Elonus excavatus Werner, from Arizona (holotype); g, Elonus chisosensis Werner, ♂, from Arizona (paratype). h – l, n, male right antenna in dorsal view. h, Elonus basalis (LeConte), from Wisconsin; i, Elonus gruberi n. sp., holotype, from Wisconsin; j, Elonus hesperus Werner, from Mississippi; k, Elonus nebulosus (LeConte), from Texas; l, Elonus simplex Werner, from Arizona (paratype); n, Elonus chisosensis Werner, from Arizona (paratype); m, right antenna of Elonus excavatus Werner, ♂, from Arizona (holotype); o, left antenna of Elonus gruberi n. sp., ♀, from Wisconsin.

FIGURE 3. Abdominal sternites and leg morphology of male Elonus species. Abdominal sternites in ventral view (a – g) (note the variable anterior extension of the golden pubescence (white arrows )), tibiae of mesothoracic legs in dorsal view (h – n) and femora of metathoracic legs in ventral view (o – u) (note the presence of a proximal excavation in some species (empty arrowheads )). a, h, o, Elonus nebulosus (LeConte), from Texas; b, i, p, Elonus basalis (LeConte), from Wisconsin; c, j, q, Elonus gruberi n. sp., ♂ holotype, from Wisconsin; d, k, r, Elonus hesperus Werner, from Mississippi; e, l, s, Elonus simplex Werner, from Arizona (paratype); f, t, Elonus excavatus Werner, from Arizona (holotype); m, Elonus excavatus Werner, from Arizona (paratype): note the kink in the mesotibiae (black arrowhead); g, n, u, Elonus chisosensis Werner, ♂, from Arizona (paratype).

FIGURE 4. Elytral pigmentation and pubescence of Elonus species. a – d, basal orange pattern variation. a, Elonus gruberi n. sp., ♂ holotype, from Wisconsin; b, Elonus gruberi n. sp., ♂ from Texas; c, Elonus basalis (LeConte), ♂, from Wisconsin; d, Elonus hesperus Werner, ♂, from Mississippi. e – j, elytral pubescence. e, Elonus chisosensis Werner, ♂, from Arizona (paratype); f, Elonus hesperus Werner, ♂, from Mississippi; g, Elonus excavatus Werner, from Arizona (paratype); h, Elonus basalis (LeConte), ♂, from Wisconsin; i, Elonus simplex Werner, from Arizona (paratype) (note the lateral patches of short white recumbent hairs (white arrows); j, Elonus gruberi n. sp., ♂ holotype, from Wisconsin.