Hemicrepidius simplex (LeConte, 1876)

Etzler, Frank E., 2020, A Revision of the Genus Hemicrepidius Germar, 1839 (Coleoptera: Elateridae) of the New World, with Comments on Global Classification, The Coleopterists Bulletin (mo 18) 74, pp. 1-126 : 80-81

Hemicrepidius simplex (LeConte, 1876)

( Figs. 37a–e , 38b )

Athous simplex LeConte 1876: 516 ; Van Dyke 1932: 371; Fall 1934: 173; Lane 1971: 28.

Hemicrepidius simplex (LeConte) : Becker 1979a: 408; Bousquet 1991: 183; Bousquet et al. 2013: 184.

Diagnosis. Hemicrepidius simplex can be distinguished from all congeners by the following combination of features: Weakly serrate antennae; a straight to ear-like posterior margin of the hypomeron; a curved prosternal process in lateral view; scattered, subumbilicate punctures on the pronotal disc similar in size to punctures on the head; and slightly divergent hind angles.

It is most similar to H. falli , and characters to distinguish the species are given in the Diagnosis of that species as well as the key to species.

Redescription. Length 7.5–12.0 mm, width 2.0–3.0 mm; color red-brown to brown, elytra not contrasting with pronotum, legs, antennae and ventral side paler, yellow-brown; integument shining. Setae moderately long, suberect, yellow. Head: Punctures subumbilicate, nearly contiguous; frons weakly concave anteromedially, some with slight triangular impression medially in dorsal view; frontal carina broadly rounded to roughly V-shaped, complete when viewed from the front, frontoclypeal region complete and narrow medially, frontal carina weakly projecting in lateral view; eyes large and moderately bulging, ocular index 66–70 (n = 2); antenna weakly serrate, antennomere 2 subcylindrical, antennomere 3 subcylindrical, slightly longer than 2 and with similar setation, antennomere 3 half length of 4, antennomeres 4–11 about 3× longer than wide, often with subtle medial line bearing less setae than edges, antennomere 11 oval or with tip weakly constricted, antenna extending beyond pronotal posterior edge by 1–3 antennomeres. Prothorax: Pronotum 1.1–1.3× wider than long, widest at hind angles or just anterior of midlength; sides weakly to broadly arcuate, gradually narrowing on anterior half, lateral margin dorso-ventrally flattened anteriorly; hind angles subparallel to slightly divergent with lateral edge sinuate anterior of hind angle, dorsal carina variable, in most absent, present in a few, thin and directed antero-medially; punctures on disc same size as punctures on head, subumbilicate, scattered, some nearly touching, separated by less than half a puncture diameter to three puncture diameters, punctures closer laterally, nearly touching, separated by half a puncture diameter or less; posterior edge with small sublateral notches best visible at high magnificaton (50×). Hypomeron with subumbilicate punctures, nearly touching anteriorly, separated by half a puncture diameter or less, and becoming less dense posteriorly, often with impunctate area on posterior one-fourth; posterior margin straight to ear-like so hind angle not visible in ventral view ( Fig. 37c ). Prosternum with punctation smaller than punctation on hypomeron, punctures nearly touching laterally, less dense medially; anterior lobe slightly deflexed, short, nearly truncate to broadly rounded, not covering ventral mouthparts; prosternal process curved dorsad between procoxae in lateral view, narrow and sinuate past procoxae. Pterothorax: Mesoventral cavity with lateral edges sinuate, not visible anteriad mesocoxae in lateral view; posterior edge of cavity narrowly truncate. Metaventrite with punctures simple, smaller than punctures on hypomeron, separated by one to two puncture diameters throughout. Scutellar shield elongate, about twice as long as wide, narrowly rounded posteriorly, sides sinuate, dorsal surface flat, anterior margin nearly straight, punctation small, setae radiating from midline, similar in length and color to setae on pronotum and elytra. Elytral striae at most weakly impressed basally; interstriae flat to slightly convex, punctures small, even, giving wrinkled appearance; basal carina simple. Legs with lobe on tarsomere 3 largest, narrow, lobe on tarsomere 2 small, narrow, lobes on tarsomeres 1 and 4 minute, visible only in ventral view. Abdominal ventrites: Punctures simple, slightly smaller than punctures on metaventrite, separated by one puncture diameter throughout; fifth ventrite narrowly rounded; lateral microserrations small, visible at high magnificaton (50×), not visible on ventrite 5. Male genitalia ( Figs. 37d, e ): Parameres subparallel on basal twothirds, slightly sinuate basal to pre-apical expansion, apex of paramere rounded, membranous, and setose ventrally. Median lobe narrow, subparallel on basal four-fifths and gradually narrowing towards apex; basal struts forming 90-degree angle directed latero- basally. Basal piece with majority of area membranous, broadly rounded medially. Aedeagus elongate, approximately 3.3× longer than wide (apex of median lobe to base of basal piece/widest part of basal piece).

Distribution. Specimens were examined from the following states: UNITED STATES: CO, MT, NM, UT, WY ( Fig. 38b ). Becker (1979a) examined 12 specimens of this species, only one of which is among those examined here, and that is the holotype. Becker’ s remaining 11 specimens are from two localities in British Columbia, two localities in Colorado, and a locality each in Idaho, New Mexico, and Washington. These are included in the distribution map as state and province records only (stars).

Notes. The relatively small number of specimens known for this species suggests it is rarely collected. However, targeted, long-term collecting, such as has been done in Montana, should increase the number of specimens for this apparently uncommon species throughout its range.

Larvae have not been associated with this species.

Types Examined. Of Athous simplex : Holotype: Col/ A. simplex Lec / Type 2546; male; type locality Colorado; in MCZC.

Horn Collection (4, MCZC). N.M./ Athous simplex Lec. (1); Leadville, Col., H. F. Wickham, July-7-14-[18]96, 10,000-11,000ft (3).

Other Specimens Examined (32). UNITED STATES: Montana: Cascade Co., Great Falls Super Site, 47.5016°N, 111.2065°W, May- 19-July- 2011, USDA, EtOH LindFnl (1, MTEC) ; Flathead Co., Glacier National Park, N. Fork Flathead area , 1988 Red Bench Fire Study, M. A. Ivie colr./ Hidden Mdw Rdg , 4080ft, old growth hard burn, T35N, R20W, Sec 19, 09-Jul-02-Aug-1989 / Lidgren funnel trap (1, MTEC) ; Glacier National Park, N. Fork Flathead area , 1988 Red Bench Fire Study, M. A. Ivie colr/ S. Big Prairie, 3560ft, old growth unburned, T35N, R21W, Sec 16, 01-Aug-[19]89, 31- Jul-07-Aug-[19]90/ Lindgren funnel trap, center light trap (2, MTEC) ; Glacier National Park, N. Fork Flathead area, 1988 Red Bench Fire Study, M. A. Ivie colr/ Sullivan old growth, unburned, 3560’, T34N, R20W, Sec 21, 03-Aug-[19]89, 14-21-Aug- [19]91, 12-19-Aug-1993 / Lidgren funnel trap (3, MTEC) ; Glacier National Park, N. Fork Flathead area, 1988 Red Bench Fire Study, M. A. Ivie colr/ Bowman Lake Road, lodgepole hard burn, T35N, R21W, Sec 14, 16-23-Jul-1991 (1, MTEC) ; Glacier National Park, N. Fork Flathead area, 1988 Red Bench Fire Study, M. A. Ivie colr/ Bowman- Akokola inst., old growth hard burn, T35N, R21W, Sec 15, 3600ft, 15-23-Jul-1992 / Lindgren funnel trap (2, MTEC) ; Glacier National Park , W. Glacier Head Qtr., 04-15-Jul-1991, 02-14-Aug- 1991, M. A. Ivie, colr/ UV light trap (6, MTEC) ; S. Whitefish, MR11PD07001, 48.3478°N, 114.3303°W, 07-Sept- 2011, 3160ft, USDA, LnFnl Sirex (1, MTEC) ; Lincoln Co., Lk. Koocanusa, Sutton Rd , 48.4651°N, 115.2653°W, 26-July-02- Oct- 2010, 2736ft, Kraus et al., FIT, alder (1, MTEC; DNA— MTEC023707 ) ; Granite Co., 1-90 Rest , mi143, 46.7040°N, 113.3375°W, 07-Jul-26-Aug- 2011, 3816ft, Hart, Staven, Bait LnFnl (1, MTEC) ; Missoula Co., Seeley Lake , Aug-11-1965, B. Wiegand (1, MTEC) ; Salmon Lake , 7.5mi N. Jct 200 and 83, 24-VII-1988, P. Skelley, blacklight trap (2, MTEC [ Fig. 37a ]) ; Ravalli Co., Sula Rang. Sta. site, funnel traps, pitfall traps, 26-June-31-July- 1994, D. L. Gustafson colr. (4, MTEC [ Figs. 37b, c ]) ; Warm Springs Cr. Camp , 45.8427°N, 114.0407°W, D. L. Gustafson G1776 (1, MTEC; DNA—MTEC023705 [ Figs. 37d, e ]) ; Silver Bow Co., Divide Cr. Rd, Beaver Dam cpg, 45.8829°N, 112.7816°W, 28-Jul- 2016, 6545ft, L. C. Seelye, blacklight (2, MTEC; DNA— MTEC023706 ) . Utah: Cache Co., Logan Canyon, Beaver Mtn , Jul 21-27, 1985, Nadeer Youssef, MT (1, CESC) . Wyoming: [Albany Co.?], Medicine Bow N. For., VII-31-[19]58/ D. J. and J. N. Knull collrs (1, FMNH) ; Carbon Co., Riverside , 5 mi S Black Hall Mtn. Rd, 8-Aug-1986 / under bark lodgepole pine, D. M. Field (1, BYUC) ; Teton Co. Hoback Junction, jct. Snake [and] Hoback R., 23-vii-1988, P. Skelley, blacklight trap (1, CESC) .

Figures

Fig. 37. Hemicrepidius simplex. Dorsal habitus: a) Male, b) Female. c) Pronotum, lateral view. Male genitalia: d) Dorsal view, e) Ventral view. Scale bars: 5 mm (a, b), 1 mm (c–e).

Fig. 38. Distribution maps of examined Hemicrepidius specimens (blue/gray dots). a) H. ruficornis, b) H. simplex.