Hemicrepidius falli ( Reitter, 1908 )

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 : 40-41

Hemicrepidius falli ( Reitter, 1908)

( Figs. 18a–e , 20a )

Athous quadricollis Fall in Fall and Cockerell 1907: 229. [not Athous quadricollis Desbrochers des Loges 1870: 134 ]

Athous falli Reitter 1908: 36 (replacement name for A. quadricollis Fall ); Leng 1920: 169; Van Dyke 1932: 372; Lane 1971: 27.

Hemicrepidius falli (Reitter) : Becker 1979a: 409.

Diagnosis. Hemicrepidius falli can be distinguished from all other Hemicrepidius by the combination of: A slightly projecting frontal carina when viewed laterally, the straight to ear-like posterior margin of the hypomeron; pronotal punctures smaller than punctures on head, separated by 2× diameter of a puncture at most on disc, closer and separated by less than 0.5× puncture diameter laterally; and the diverging hind angles with thin carina.

Hemicrepidius falli is most similar to species that have been historically placed in Athous , which are H. palpalis and H. simplex . From H. simplex , H. falli can be distinguished by having the punctures on the pronotal disc smaller, more simple than umbilicate, the carina on the pronotal hind angle, and the prosternal process not being strongly curved dorsad. From H. palpalis , it can be distinguished by the complete frontal margin, longer and more divergent pronotal hind angles, with the carina distinct, having yellow setae, and the weakly pointed pre-apical expansion of the aedeagal paramere.

Redescription. Length 10.0–14.0 mm, width 2.0–4.0 mm; color uniformly red-brown to dark brown, elytra not contrasting with pronotum, often with posterior and anterior edges of pronotum and ventral side pale. Setae moderately long, depressed, yellow. Head: Punctures subumbilicate, nearly contiguous; frons concave anteromedially, with triangular impression medially when viewed dorsally; frontal carina complete, broadly rounded when viewed from front, frontoclypeal region complete, narrow medially, and slightly projecting in lateral view; eyes large and strongly bulging, ocular index 58–60 (n = 3); antenna weakly serrate, antennomere 2 subcylindrical, antennomere 3 subcylindrical and 1.5× length of 2 and with similar punctation as antennomere 2, antennomeres 2 and 3 together subequal in length to antennomere 4, antennomeres 4–11 about 3× longer than wide, each with slightly less setae medially, not quite forming distinct line and less noticeable on darker specimens, antennomere 11 nearly oval or with tip subtly constricted, antenna extending beyond pronotal posterior edge by 2–3 antennomeres. Prothorax: Pronotum as wide as long to 1.2× wider than long, usually widest just anterior of midlength, sometimes widest at hind angles; sides weakly arcuate, some almost subparallel laterally, narrowing at anterior one-fourth; hind angles divergent due to sinuate edge anterior of hind angle, dorsal carina present, thin, subparallel to lateral carina; punctures appearing simple to subumbilicate when viewed at 40× magnification, separated by at most two puncture diameters on disc, punctures becoming larger and clearly subumbilicate laterally, nearly contiguous; posterior edge with sublateral notches. Hypomeron with small, subumbilicate punctures, nearly contiguous throughout, except for impunctate area on posterior one-fifth in some specimens; posterior margin ear-like, hind angle not visible in lateral view ( Fig. 18c ) or ventral view. Prosternum with punctation slightly smaller than punctation on hypomeron, less dense medially, separated by two puncture diameters at most; anterior lobe deflexed, sometimes only slightly so, broadly rounded and partially covering ventral mouthparts; prosternal process slightly curved dorsad between procoxae, narrow and straight past procoxae. Pterothorax: Mesoventral cavity with lateral edges sinuate, not visible anteriad mexocoxae; posterior edge of cavity narrowly truncate. Metaventrite with punctures simple, smaller than punctures on hypomeron, separated by diameter of one puncture laterally, further apart medially. Scutellar shield elongate, almost oval, about twice as long as wide, narrowly rounded posteriorly, sides sinuate, dorsal surface flat, anterior margin broadly convexly curved, setae radiating from midline, similar in length and color to setae on pronotum and elytra. Elytral striae weakly impressed basally; interstriae flat to subtly convex, punctures small, scattered, giving wrinkled appearance; basal carina simple. Legs with tarsomere lobes small and narrow, not visible dorsally, lobe on tarsomere 3 largest, lobe on tarsomere 2 second largest, lobe on tarsomere 4 minute, usually visible only in ventral view; lobe on tarsomere 1 smallest, very minute. Abdominal ventrites: Punctures simple, slightly smaller than punctures on metaventrite, separated by at most one puncture diameter laterally, less dense medially; fifth ventrite narrowly rounded; lateral edge of ventrites 1 to 4 with microserrations indistinct, appearing absent below magnification of 50×, not visible on fifth ventrite. Male genitalia ( Figs. 18d, e ): Parameres subparallel laterally on basal two-thirds, gradually sinuate laterally basal to pre-apical expansion, pre-apical expansion weakly pointed laterally; apex of paramere narrowly rounded, membranous, setose ventrally. Median lobe narrowly triangular, basal struts curved latero-basally. Basal piece with membranous area broadly pointed medially in ventral view. Aedeagus approximately 2.5× 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: AZ, CA, NV, OR ( Fig. 20a ).

Notes. I have examined five female specimens which I have tentatively associated with H. falli specimens. The species was previously only known from the males. From the description above, these females differ by being much larger, 17.0–20.0 mm in length; the antenna being less serrate and just reaching the posterior edge of the pronotum; the pronotum much broader and laterally rounded; and, in some, the pronotal punctation being a bit denser medially, and pronotal hind angles subparallel. Otherwise they share many characteristics with typical H. falli . Since the most recent specimen was collected in 1968, DNA extraction was not attempted on these specimens. These females can be distinguished from similarly-sized Athous species in the region by having an antescutellar notch on the posterior edge of the pronotum.

I have also included here three male specimens from Inyo County, California, that are a bit different than typical specimens. These specimens have slightly longer pronotal hind angles and the punctation on the pronotal disc is larger and appears more subumbilicate. Despite these differences, other characters are typical for H. falli . There are other specimens which are intermediate between typical H. falli and these specimens, further lending credibility to the interpretation that these small differences are merely intraspecific variation.

Types Examined. Of Athous falli : Holotype: Lake Tahoe Cal., Jul 17-21, [18]97/ quadricollis type/ Athous falli Reitt. / H. C. Fall collection/ Type #24371.

Specimens Examined (45). UNITED STATES: Arizona: [Navajo Co.], Tesgi Canyon , 8mi N of Marsh Pass, IX-4-1950 / coll. by J. P. Figg-Hobiyn (1, CASC) . California: [no data] (1, MCZC) ; Alpine Co., Carson Pass , July-23-1964, Fred G. Andrews (1, CASC) ; El Dorado Co. / H. C. Fall collection (1, MCZC) ; Inyo Co., 1.5mi E. Glacier Lodge / collected at blacklite/ E. L. Sleeper collr. (1, CASC) ; George Creek , altitude 11,300ft, 31-VII- 1971, Derham Giuliani (2, CASC) ; Mt. Whitney Trail , 2560m- 3230m, 11-July-1981, stop#81-25, D. H. Kavanaugh collector (1, CASC) ; Lassen Co., Lassen N.F., 210/ Westwood Junction , 7-18-1915 / R. Hopping collection (1, CASC) ; Madera Co. / Flight / R. L. Furniss (2, OSAC, WFIC0000353604 , WFIC0000353605 ) ; Soquel Meadow, Willow Creek / VII-1951, W. C. Day (3, CASC [ Fig. 18c ]); Placer Co., VII-25-[19]25/ F. X. Williams (1, FSCA) ; Carnelian Bay , VII-8/ E. G. Linsley (1, FMNH) ; Tahoe National Forest, Pineland Drive, 4km S. of Tahoe City , 1900m, 5-VIII-1983, Thomas W. Davies (2, CASC) ; [Plumas Co.], Chester , VII- 11-[19]51 [ Fig. 18a ], VII-4-[19]58, VI-30-[19]60 [ Figs. 18d, e ]/ D. J. & J. N. Knull Collrs. (7, FMNH) ; Plumas Nat. For. , 8-18-[19]50/ Coll. Lee Colston (1, BYUC) ; Lassen View Camp , VII-3-[19] 47/ W. Lee collector (1, CASC) ; [County?] Riverton Cal. , 3000ft 7-30/ Hinton Col. (1, BMNH) ; [Shasta Co.], Castella , VII-7-8-1912 / Van Dyke collection (1, CASC) ; Cayton , VII-17/ R. Hopping collection (1, CASC) ; SW of Old Station , ca 11mi S Hat Creek, 14-July-1989, R. S. Zack, at lights (1, WSUC) ; Siskiyou Co., McCloud , 7-17-[19]56/ D. Giuliani collector (2, CASC) ; Ash Creek Sta., VII-8-[19]64 [?], D. H. Hennings (1, CASC) ; Tuolumne Co., Pinecrest ,7-29-[19]46/ W. Russell collection (1, CASC) ; Pinecrest , ca 1700m, 28-VII-1947, 31-VII- 1947 [ Fig. 18b ], Paul H. Arnaud Jr. (2, CASC) ; Twain Harte , VII-27-1982 / M. R. Lundgren collector (1, CASC) ; Tulare Co., 7-21-[19]12/ H. C. Fall collection (1, MCZC) ; [ County ?] Y. S./ O. S. Wescott collection (1, WSUC) . Nevada: [no data]/ Fredrick Blanchard Collection (1, MCZC) . Oregon: [Klamath Co.], Klamath Falls , 6-24-[19]31/ Y. Pine stump in pitch/ R. L. Furniss collector (1, OSAC, WFIC0000397138 ) . Associated females : UNITED STATES: California: Plumas Co., Thompsons Crk , July-25-1953, F. X. Williams (1, CASC) ; Siskiyou Co., Everitt Memorial Highway , alt. 6520 feet, 6-VIII-1968, Hugh B. Leech (1, CASC) ; Tulare Co., Giant Forest , I-15-[19]05, R. Hopping (1, CASC) ; Giant Forest, Round M’ d’ w, Aug, Hopping (1, CASC) ; Tuolumne Co., Pinecrest , ca 1700m, 31-VII-1947, Paul H. Arnaud, Jr (1, CASC) .

Figures

Fig. 18. Hemicrepidius falli. 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. 20. Distribution maps of examined Hemicrepidius specimens (blue/gray dots). a) H. falli, b) H. hemipodus.