Hemicrepidius bilobatus ( Say, 1836 )

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 : 28-30

Hemicrepidius bilobatus ( Say, 1836)

( Figs. 5b , 9a , 10c , 11a–e )

Elater bilobatus Say 1836: 174 .

Asaphes bilobatus (Say) : LeConte 1853: 452; Candèze 1863: 222; Horn 1880: 74; Blatchley 1910: 769.

Hemicrepidius bilobatus (Say) : Wickham 1911: 23; Leng 1920: 170; Thomas 1941: 247; Owen and Jaques 1943: 343; Dietrich 1945: 30; Bousquet 1991: 183; Majka et al. 2011: 139; Bousquet et al. 2013: 184.

Athous fastiditus Dejean 1836: 101 [nomen nudum]; Candèze 1863: 221 (as synonym of H. melanopthalmus ). New synonymy.

Asaphes consentaneus LeConte 1853: 452 ; Candèze 1863: 222 [not examined by Candèze]; Horn 1880: 75 (as synonym of H. bilobatus ).

Asaphes planatus LeConte 1853: 453 ; Candèze 1863: 223 [not examined by Candèze]; Horn 1880: 75 (as synonym of H. bilobatus ).

Diagnosis. Hemicrepidius bilobatus can be distinguished from all other Hemicrepidius by the lack of a carina on the pronotal hind angle, the lack of sublateral notches along the posterior edge of the pronotum, the pronotal hind angle broad dorsally, about as long as wide ( Fig. 9a ), and the male aedeagus with parameres subparallel on basal two-thirds, gradually narrowing before expanding to hooked pre-apical expansions, with apex of the parameres acute ( Figs. 11d, e ).

Hemicrepidius bilobatus is most similar to H. memnonius and H. melanopthalmus . The lack of a carina on the pronotal hind angle and the lack of sublateral notches will readily separate H. bilobatus from H. memnonius . From H. melanopthalmus , H. bilobatus can be distinguished by the darker color, the wider pronotal hind angles in dorsal and ventral views ( Figs. 11a–c ), the parameres of the aedeagus not being laterally compressed basal to the preapical expansions, and with the basal struts of the median lobe angled ( Figs. 11d, e ).

Redescription. Length 11.0–18.0 mm, width 3.0–5.0 mm; color dark red-brown, elytra not contrasting in color; pronotum, legs, antennae and sometimes posterior edge of pronotum, edges of elytra, and edges of abdominal ventrites paler. Setae moderately long, depressed, yellow. Head: Punctures subumbilicate, nearly contiguous; integument shining; frons weakly concave anteromedially in dorsal view, some with slight triangular impression medially in dorsal view; frontal carina complete, roughly V-shaped when viewed from the front, frontoclypeal region absent medially, at most weakly projecting in lateral view; eyes large and strongly bulging, ocular index 55–66 (n = 3); antenna weakly serrate, antennomere 2 subcylindrical, antennomere 3 subcylindrical and 1.5× length of 2, antennomere 3 subequal in length to 4, antennomeres 4–11 about 3× longer than wide, each with medial line bearing less setae than edges (cf. Fig. 5d ), antennomere 11 with tip constricted as a pseudosegment, antenna extending beyond pronotal posterior edge by 1–2 antennomeres. Prothorax: Pronotum as wide as long (males) to 1.2× wider than long (females), widest at hind angles or just anterior of midlength; sides weakly arcuate, almost subparallel, narrowing at anterior one-fourth; hind angles usually subparallel, sometimes appearing slightly divergent due to sinuate edge anterior to hind angle, dorsal carina absent; punctures large, subumbilicate, separated by one to two diameters of a puncture on disc in females, nearly touching in males, punctures closer laterally, nearly contiguous, integument shining; posterior edge without sublateral notches. Hypomeron with large, subumbilicate punctures, nearly contiguous anteriorly, less dense posteriorly; posterior margin emarginate with hind angle visible ventrally and truncate at tip ( Fig. 11c ). Prosternum with punctation matching that of hypomeron, less dense medially; anterior lobe slightly deflexed, broadly rounded and covering ventral mouthparts; prosternal process slightly curved dorsad, narrow and straight posterior to procoxae. Pterothorax: Mesoventral cavity with lateral edges sinuate in lateral view, not visible anteriad of mesocoxae, posterior edge of cavity truncate. Metaventrite with punctures subumbilicate, smaller than punctures on hypomeron, dense throughout, nearly touching. Scutellar shield elongate, about twice as long as wide, narrowly rounded posteriorly, sides sinuate, dorsal surface weakly convex, anterior margin nearly straight, setae radiating from midline, similar in shape, length, and color to setae on pronotum and elytra. Elytral striae moderately impressed basally; interstriae flat to slightly convex, integument shining with wrinkled appearance; basal carina simple. Legs with lobe on tarsomere 3 largest, wide; lobe on tarsomere 2 second largest, wide; lobe on tarsomere 4 minute, visible only in ventral view; lobe on tarsomere 1 smallest, visible only in ventral view. Abdominal ventrites: Punctures small, simple, a bit smaller than punctures on metaventrite, moderately dense, separated by one puncture diameter, less dense medially; fifth ventrite broadly rounded; side of each ventrite with microserrations. Male genitalia ( Figs. 11d, e ): Aedeagus with parameres broadly triangular apically, subparallel on basal two-thirds with broad sinuation on apical one-third just posteriad of pre-apical expansion; pre-apical expansion hooked laterally, dense setose patch ventrally near pre-apical expansion, 3–5 dorsal apical setae. Median lobe broadly triangular, basal struts angled near 90 degrees. Basal piece with membranous area transverse medially.

Distribution. Specimens have been examined from the following: UNITED STATES: AL, AR, GA, IA, IL, IN, KS, KY, LA, MD, MO, MS, NC, NJ, NY, PA, OH, SC, TN, VA, WI ( Fig. 10c ). Canadian records (e. g., Bousquet et al. 2013) need to be confirmed, and likely belong to H. melanopthalmus , a species removed from synonymy with H. bilobatus .

Notes. Due to the application of a refined species concept and the missing type specimen, I have designated a neotype to solidify this concept. I have chosen to make the first specimen in the LeConte collection the neotype. This specimen bears LeConte’ s identification label and has a yellow disc, which represents the area of the United States that includes Indiana, the type locality of Say’ s missing specimens .

The color and setation of this species make it surprisingly easy to confuse with H. memnonius . I have seen many specimens misidentified as this latter species. One specimen of note is Germar’ s fourth syntype of H. thomasi in the BMNH, which is a typical specimen of H. bilobatus .

Historically, H. bilobatus has been confused with H. melanopthalmus . In addition to the morphological differences discussed in the diagnosis above, there are genetic differences ( Figs. 1–3 ). The trees suggest that H. bilobatus and H. melanopthalmus are sister species (basal support 99 or 100), and distinct species.

Specimens in the BMNH collected by Palisot de Beauvois, labeled as being from San Domingo (historic name for the island of Hispaniola in the Greater Antilles) require further examination. Many specimens collected by Palisot de Beauvois are now known to have incorrect collection localities, with some American species being described as coming from Africa and vice versa ( Chase 1925). It is likely these BMNH specimens are mislabeled. A thorough search of the West Indian Beetle Fauna Project (WIBF) collection at Montana State University yielded no specimens of H. bilobatus from Hispaniola, or any other West Indian island; therefore, the locality on these specimens is treated as an error.

Larvae have been tentatively associated with this species ( Glen 1950).

Type Specimens. Of Elater bilobatus : Holotype missing; type locality Indiana. Neotype, here designated: [yellow disc]/ A. bilobatus Say / bilobata #1; in LeConte Collection; in MCZC. Of Asaphes planatus : Holotype: [pink disc]/ H. planatus Lec. N.G. / type 2616/ bilobata #13; type locality New Jersey; in MCZC. Of Asaphes consentaneus : Holotype: [pink disc]/ A. consentaneus Lec. bilobatus male?/ type 2615/ bilobata #7; type locality New York; in MCZC.

LeConte Collection (6, MCZC). [yellow disc]/ bilobata #2 & bilobata #3; [no disc]/ bilobata #4; [pink disc]/ bilobata #8; [yellow disc]/ bilobata #9; [orange disc]/ bilobata #10.

Other Specimens Examined (81). NORTH AMERICA: 85-53 [code on label] (2, BMNH); A. melanopthalmus Melsh / Coll. Janson, Ex Dejean/ Athous fastiditus mihi (pars), h. in Amer. Bor., D. Beauvois [5] [one w/ green “Say” label] (3, BMNH); green rectangle/ Coll. Janson, Ex Dejean/ A. melanopthalmus Melsh. , Ath fastididus Dej., Amer. Bor. Beauv. / Athous fastididus var longicornis Harris , in Amer. Bor, D. LeConte [3] (1, BMNH); [red rectangle]/ [blue]296/ Ex Deyrolle, Coll. Janson/ Asaphes sp. , Amer. Bor./ A. fastiditus Dy, Amer. Bor [Abd missing since 1977] (1, BMNH); 30/ Coll. Janson, Ex. Mniszech, ID label Amer. Bor (1, BMNH); Coll. Janson, Ex Schaum/ memnonius , thomasi ID label/ Am. Bor. [Germar H. thomasi syntype, #4] (1, BMNH); [red rectangle]/ [yellow]458/ A. bilobatus Say, Amer. Bor / Coll. Janson, Ex Deyrolle (1, BMNH). UNITED STATES: Alabama: [Mobile Co.], Mobile/ Coll. by H. P. Loding (1, CASC; 1, MCZC), VI-4-[190]8 (1, MCZC). Arkansas: [Washington Co.], Fayetteville, VII-16-1942, M. V. Sanderson/ in light trap (1, INHS 830270). Georgia: No data (1, MCZC); Union Co., Blairsville, 18-24 June 1990, P. J. Landolt (1, FSCA). Illinois: [no data]/ Andreas Bolter Collection (1, INHS 830292); [5476] (1, INHS 830268); E. St. Louis, June 26, 1931, Frison, Betten & Ross (1, INHS 830193); Elizabethtown, July 4, 1948, Mills & Ross/ At light (1, INHS 830266); Peoria, May 26, 1938, June 20, 1938, Aug. 1, 1942, F. F. Hasbrouck (3, INHS 830393, INHS 830400, INHS 830405[ Fig. 11a ]). Indiana: Bloomington, 7.13.[19]38, Daris[?] coll (1, PMNH); Tippecanoe Co., V-16-1986, N. M. Downie (1, FSCA) Lafayette, 8-21-1985, 4-Jul-1989, 7-17- 1990, 7-18-1990, 7-20-1990, 7-24-1990, 28 July 1990, U-V light, N. M. Downie (6, FSCA; 1, WSUC). Iowa: [no data]/ Fall Collection (1, MCZC). Kansas: Douglas Co., F.H. Snow (1, SEMC); Lawrence, 7-15-1925, W. Benedict (1, SEMC). Kentucky: [Jefferson Co.], Louisville, VII-17 (1, MCZC). Louisiana: [Winn Parish], Winnfield, 6/ 21/ Fall Collection (1, MCZC). Maryland: Anne Arundel Co., Edgewater, 12-15 July 1991, C. L. Staines, blacklight (1, FSCA). Mississippi: Yallobusha [sic] Co., Water Valley, 10-20 VII- 1971, Michael Horan, Malaise Trap (1, FSCA). Missouri: St Louis, VII-10 (1, MCZC). New Jersey: [no data], R. Hopping Collection (1, CASC); [No locality], VII-29 (1, MCZC). North Carolina: [Haywood Co.], L. Junaluska/ H. V. Weens, Jr, coll. 1 VIII [19] 57/ 2 VIII [19]57/ 3 VIII [19]57/ coll. at light (3, FSCA). Pennsylvania: [no data]/ Van Dyke Collection (1, CASC); [no data] (3, MCZC); [Allegheny Co.], Allegh[e]ny/ Liebeck Collection (3, MCZC, MCZ-ENT 00642007); Allegh[eny]/ R. Hopping Collection (1, CASC); All[eghen]y (1, SEMC); Pittsburg, VII-20, VIII-7, VIII-10 (3, OSAC), VIII-10/ J. W. Green Collection (1, CASC); [Dauphin Co.], Rockville, VII-8-[19]10 (1, MCZC); [Indiana Co.], Indiana, 10-1930/ Hinton Coll. (1, BMNH); [Northampton Co.], Easton, VII-26-[19]45, J. W. Green (1, CASC); [Philadelphia Co.], Phila [delphia], VII-15/ J. W. Green Collection (1, CASC), VII-14 (1, MCZC), 7-20 (1, MCZC); [Westmoreland Co.], Jeannette (1, MCZC). Ohio: Franklin Co., Columbus, 20 Aug. 1989, R. S. Miller Colr. (1, MTEC; [ Fig. 11c ]); [Hamilton Co.], Cincinnati, 7-23- [19]38, W. D, Hartman (1, PMNH). South Carolina : Pickens Co., Clemson Twp, Clemson University, Cherry Farm, N34.6531, W82.8344, at light, 26 May 2019, Anthony Martin Deczynski (1, AMDC). Tennessee: Sevier Co., GSMNP, ATBI Plot, Twin Creeks, 273810E, 3951793N/ Malaise Trap MT02, 31 Jul- 15Aug 2002, B. Merritt (1, LSAM; [ Fig. 11b ]); GSMNP, Twin Creeks ATBI plot, MT-0119990817, 9-17 August 1999, MT-019990902, 17 Aug – 2 Sept 1999, MT-0120000619, 5-19 June 2000, Parker, Stocks, and Peterson (3, LSAM 0103597, LSAM 0103554, LSAM 0103462). Virginia: Arlington Co., Arlington, 38.859°N, 77.123°W, 16-VII-2014, M. A. Johnston (1, FEEC, DNA—MTEC023671 [ Figs. 11d, e ]); Fairfax Co., Scott’ s Run, 21-VII-1963 / D. C. & K. A. Retz Collectors (1, CASC). Wisconsin: Purple disc/ Coll. Janson, Ex Candèze/ [ID label w/ locality] (1, BMNH); Coll. Janson., Ex Candèze/ Asaphes bilobatus Say (1, BMNH). Gold disc (1, MCZC).

Incorrect Localities. Hispaniola: Coll. Janson, Ex Dejean / A. melanopthalmus Melsh., Ath. subglaber Beauvois, S. Domingo [this Dejean ID label only on one specimen]/ S. Domingua, D. Beauvois [2] (2, BMNH) .

Figures

Fig. 5. Morphological characters of Hemicrepidius. Tarsi, lateral view: a) H. memnonius, b) H. bilobatus, scale bar between = 1 mm. Antenna types: c) Strongly serrate, with triangular antennomere 3 (H. niger), d) Serrate, with impunctate medial line (ml, arrow) of antennomeres (H. memnonius), e) Serrate, lacking medial line (H. californicus), f) Weakly serrate (H. hemipodus), all to scale, scale bar below d = 1 mm. Mesothorax: g) Lateral edges of mesothorax raised in near 90-degree angle, arrow (H. californicus), stepped line to highlight character, scale bar below body = 1 mm.

Fig. 9. Morphological character measurements. Hemicrepidius bilobatus: a) Measurement of pronotal hind angle in dorsal view. H. tumescens: b) Measurement of pronotal hind angle in ventro-lateral view, d) Measurements of aedeagus. H. memnonius: c) Location of ventral setal patch (vsp) on paramere. L = length, w = width. Not to scale.

Fig. 10. Characters and distribution. Hemicrepidius memnonius: a) Hind wing, RC = radial cell, WC = wedge cell, veins labeled following Costa et al. (2010). Stenagostus: b) Aedeagus, ventral view. H. bilobatus: c) Distribution map of examined specimens (blue/gray dots).

Fig. 11. Hemicrepidius bilobatus. Dorsal habitus: a) Male, b) Female. c) Pronotum, lateral view. Male genitalia:

Figs. 1–2. 1) Bayesian tree of CO1 and 28S; values shown are posterior probabilities; Elaterinae clade not to scale, shortened to fit in figure; scale bar represents 4% genetic variance. 2) Maximum likelihood tree of CO1 and 28S; values shown are ultra-fast bootstrap; Melanotus clade not to scale, shortened to fit in figure; scale bar represents 5% genetic variance. Both figures: Branches with support values below 80 were collapsed. Red clade represents Hemicrepidius species. Blue arrows indicate Central American species removed from Hemicrepidius and placed into Athous.

Fig. 3. Maximum likelihood tree of CO1 barcode region. Values shown are ultra-fast bootstrap values. Branches with values below 80% are collapsed. Only selected basal branches and Hemicrepidius values are given. Blue clades represent Athous species. Green clades represent species in the Limonius group of genera (Etzler 2019). Purple clades represent genera in Dendrometrini (Cate 2007). Red clade represents Hemicrepidius species. Black clades are remaining groups. Blue arrows indicate Central American species removed from Hemicrepidius and placed into Athous. Scale bar represents 7% genetic variance. Taxa and groups given in Tables 1 and 2.