Helops convexulus LeConte, 1862

Nabozhenko, Maxim, Nikitsky, Nikolay & Aalbu, Rolf, 2016, Contributions to the knowledge of North American tenebrionids of the subtribe Cylindrinotina (Coleoptera: Tenebrionidae: Helopini), Zootaxa 4136 (1), pp. 155-164 : 160-161

Nalassus (?) convexulus ( LeConte, 1862) , comb. n.

convexulus LeConte, 1862: 353 (Helops) ; Horn 1870: 396 ( Helops ) ( Helops ).

= montanus LeConte 1879:518 ( Helops ). The name was synonymized by Bousquet and Campbell (1991: 258). = regulus Blaisdell 1921:227 (Helops) . Synonymy by Boddy (1965:177).

Type material ( H. regulus ). Holotype (♀),with labels: “ Helops regulus Blais. , Type ♀”, ‘Wawawai, Wash., M M Mann V:15:09”, “Blaisdell Collection”, California Academy of Sciences Type No. 2937” CASC.

Other material examined: Pateros (Washington), April 24, 1964, R. Nagle col. (1); “Vernon, B.C” (British Columbia, Canada), “R Hopping, III 27 28 ”, “J. W. Green Collection”, (2); “Cranbrook, B.C. (British Columbia, Canada), 28 IV 1956, Lot 4, BF&JL Carr” (1); “Durkey, Ore.” (Oregon), “ VI-17-41, Km&DM Fender” (1); “Salt Lake, Ut.” (Utah), “ Mar. 31, 1913, Timberlake col.” (2).

Comments. The subgeneric position of this species is also unclear. The males have a roughly triangular shaped setal brush on the first abdominal ventrite but the coarse, sparse punctures on all ventrites are similar. The male genitalia is also very similar to N. aereus (fig. 5).

Although very similar in shape and size, there seems to be a distinct difference between specimens from the “rocky mountains” area and those from the pacific coast. In specimens (males and females) from the Rocky Mountains, the antennal segments are clearly thicker than those from the Pacific Coast. Helops convexulus was described by LeConte from “Bitter Root Valley, Rocky Mountains” in Montana. In the specimens listed above, the thicker antennal segments are found in the specimens from Utah and Montana while in the specimens from Oregon, Washington and British Columbia, the antennal segments are clearly consistently thinner. It is unclear why Blaisdell, while describing Helops regulus , compared this new species to H. pernitens and H. aereus rather than to H. convexulus . Perhaps he had no available specimens of this species. Boddy (1965), when synonymizing H. regulus , gave no reason why he did so. Finally Doyen in 1985 (unpublished) determined the specimens above from Vernon and Cranbrook (B.C.) to be Helops regulus . Perhaps he recognized this difference although it remains unpublished. Examination of additional specimens may allow both of these species to be recognized as valid.

Distribution. USA: California, Oregon, Nevada, Washington, Utah, Colorado, Nebraska, Wyoming; Canada: British Columbia, Alberta.