Boreocanthon halffteri Edmonds, 2022

Edmonds, W. D., 2022, Taxonomic review of the North American dung beetle genus Boreocanthon Halffter, 1958 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini), Insecta Mundi 2022 (952), pp. 1-65 : 45-48

Boreocanthon halffteri Edmonds , new species

Fig. 82–89

Type material. Male holotype, Texas A&M University Insect Collection ( TAMU-ENTO X0294090), TX: El Paso Co., red dunes 14 [sic] NE of Fabens, VII-11-96, C. Wolfe & D. Marqua .

Type locality. Texas: El Paso Co., red dunes, 14 [mi] NE Fabens.

Etymology. It is my great pleasure to dedicate this species to my late friend and colleague of almost 60 years, Gonzalo Halffter †, in honor of his distinguished career as a taxonomist, biogeographer, environmentalist, conservationist and dung beetle behaviorist, and founding father of the Instituto de Ecología, A.C., in Xalapa, Veracruz.

Diagnosis. Head: Anterior portion clypeus ( Fig. 89 ) finely rugose, not strongly shinier than rest of head, posterior part of head finely, evenly punctate on weak shagreen background. Clypeal teeth ( Fig. 83–84, 89 ) strong, acute apically, middle pair separated by broad, rounded emargination. Paraocular notch broad and shallow, setting off conspicuous, rounded anterior angle of paraocular area. Labio-gular fimbria bowed posteriorly, interrupted medially by broad, V-shaped field of coarse, setigerous punctures. Prothorax: Pronotum ( Fig. 83, 87 ) very finely sculptured, minute puncturing and shagreen; anterior angles broadly explanate beginning at lateral angle, widening anteriorly; posteromedian angle not depressed. Hypomeral carina absent. Pterothorax: Mesoventrite weakly punctured medially, smooth laterally. Metaventrite weakly, sparsely punctate on shagreen background. Elytra: Interstriae ( Fig. 83, 88 ) with strong shagreen and dense microspotting, more strongly sculptured than pronotum; 2 nd and 3 rd not swollen anteriorly, 3 rd and 5 th each with small tubercle in middle of anterior margin. Striae well marked, with sharply defined margins at least anteriorly; subhumeral (8 th) stria ( Fig. 88 , arrow) strongly carinulate to point usually at least midway to elytral apex; epipleural (9 th) stria obsolete. Legs: Protibia weakly, if at all, offset along inner margin; apical spur sexually dimorphic, apically acute in female, bifurcate in male. Hind femur lacking row of conspicuous setae along anterior margin. Abdomen: Pygidium sculptured as pronotum, flattened except for slightly swollen apex. Last (6 th) ventrite punctured; other ventrites smooth. Genital capsule: Compressed distal portion of parameres ( Fig. 85 ) triangular, ventral apical angles in form of elongate knobs ( Fig. 86 ). General: Black, no hint of colorful undertones anywhere. Length: 4.5 – 6.5 mm. Geographic distribution ( Fig. 82 ): Rio Grande basin of central New Mexico and far west Texas and adjacent Chihuahua ( Fig. 82 ). Ecogeographic environment ( Fig. 2 ): Desert and Xeric Shrublands biome (Chihuahuan Desert ecoregion). Specimens examined: 121.

Notes on the holotype. The holotype male ( Fig. 83–84 ) conforms with the diagnosis above annotated as follows: Left protibia-tarsus missing. Pronotal microspots dense, almost contiguous in some places. Edges of elytral striae 1–6 sharply defined by carinulate margins for almost entire length; 8 th elytral stria with strong carinula extending from umbone to point even with first abdominal ventrite; 9 th stria obsolete but vaguely indicated. Apex of pygidium distinctly convex, somewhat shinier than base, microspots virtually effaced, shagreen extremely fine (×50). Last abdominal ventrite with small, shiny bump at middle of posterior margin. Genital capsule not extracted. Length: 6.0 mm. The holotype was chosen because it conserves almost unblemished surface sculpturing. It carries the following five labels: (1) TX: El Paso Co., red dunes 14 NE of Fabens, VII-11-96, C. Wolfe & D. Marqua. (2) ex. Charles S. Wolfe Collection, June 2006, TAMU Insect Collection. (3) TAMU-ENTO, X0294090. (4) [small light yellow circle]. (5) HOLOTYPE, Boreocanthon halffteri Edmonds, 2022 . [Label notes: Distance units not specified in label (1), presumed to be 14 miles . Small yellow circle is reference to habitus photographs, Fig. 83–84 . All labels on white paper printed in black, HOLOTYPE in red].

Collection localities.

MEXICO — CHIHUAHUA: Mpio. Juarez ● Samalayuca [Jun].

UNITED STATES — NEW MEXICO: Bernalillo Co. ● Albuquerque [Jun-Jul, Oct] ● Volcano Cliffs, Albuquerque [Aug]; Doña Ana Co. ● 2.5 mi N Mesquite [Oct] ● USDA Jornada Experimental Range, 32.619590 -106.787845, 4356 ft [Jul-Aug] ● Anthony [Jun]; Sandoval Co. ● Coronado State Park, Bernalillo [Aug]; Socorro Co. ● Bosque de Apache NWR [Jul] ● Sevilleta NWR, Rio Salado [Jul] ● 17 km SW/S Bernardo, 34.292° N 106.928° W [Jul] ● Sevilleta NWR, LTER Site 3,4 [Jul, Sep]; Torrance Co. ● Town of Gran Quivara, 6500 ft [Aug]; Valencia Co. ● 5 mi N Belen [Jul]. TEXAS: El Paso Co. ● red dunes on Montana Ave., 31.841°N 106.131°W, 1245 m [AugSep] ● 14 mi NE Fabens [Jul].

Paratype data (arranged by institutional/personal collection; all bear my determination labels printed in black on white paper with PARATYPE in blue and dated either 2021 or 2022; no allotype designated):

American Museum of Natural History. New York NY – 3 females, Samalayuca Chih[uahua] Mexico, vi-24-47, Rockefeller Exp[edition], [C.D.] Michener, Accession Codes 00011194–96. Arizona State University, Hasbrouck Insect Collection, Tempe AZ – 1 male, NM Doña Ana Co., Anthony, 24-vi-70, M. Cazier, sandy hills, depressions, Atriplex ASUHIC 0145853. California Academy of Sciences, San Francisco CA – 28: 12 males, 15 females, New Mex., Torrance Co., Town of Gran Quivara, 6500 ft. alt., 29-viii-1967, Hugh B. Leech, ex vertical tunnel in sandy soil; one female, New Mex., Torrance Co., Town of Gran Quivara, 29-viii-1967, Hugh B. Leech, with humus in burrow. Carnegie Museum of Natural History, Pittsburgh PA – 4: 2 males, one female, TX: El Paso Co. Red Sands, US 62, 180, Sept. 17, 1985, Col. G.A. Coovert, GAC 1254; one male, NM: Bernalillo Co., Albuquerque, X-18-1928, H. Klages Collection, CM Acc No. 11414. Monte L. Bean Life Science Museum, Brigham Young University, Provo UT – one male, NM: Sandoval Co., Coronado State Park, Bernalillo, 21 Aug 1985, Bauman, Huish, Nelson, Wells, Whiting. Museum of Southwestern Biology, University of New Mexico, Albuquerque NM – 29: one male, Socorro Co. NM, Jul 89, C. Blanco M.// MSB Cat. No. 8226; 3 females, one male, NM: Socorro Co., Sevilleta NWR , Rio Salado, vii-17-1995, D. Holiday; 3 females, 2 males, USA NM Socorro Co. , 17 km SW/S Bernardo, N 34.292 W 106.928, 17 July 1998, coll. S.L. Brantley // MSB Cat. No. 17784–17790; 2 males, one female, Bernalillo Co., NM, Volcano Cliffs, Alb., 10 Aug 1979, C. S. Crawford // MSB Cat No. 7851–7854; 2 males, Valencia Co, NM, 5 mi N Belen, 21 July 1987, K. Flies // MSB Cat No. 7855 and 7857; 2 females, one male, Socorro Co., NM, Sevilletta [sic] sand dunes, 20 April 1982, C. S. Crawford; 3 females, one male, Socorro Co. NM, Sevilleta NWR, LTER Site 3, 4 Sept. 1992; 2 males, USA New Mexico, Dona Ana Co., USDA Jornada Experimental Range, 32.619590 -106.787845, 17 August 1989, 4356’elev., mesquite dunes, pitfall trap, D. C. Lightfoot collector; one male, Socorro Co. NM, Sevilleta NWR, LTER Site 3, 31 July 91; one male, N. Mex., Dona Ana Co., 2.5 mi N Mesquite, 2 Oct 1982, D. Lightfoot; one female, Socorro Co. NM, Bosque de Apache NWR , line A, trap #6, 14 July 1996; one female, Bernalillo Co, NW Albuquerque, 16-VI-93, Dick Fagerlund // MSB Cat. No. 8225; one female, N. Mex., Dona Ana Co., Jornada Range, 15 m N of Las Cruces, 24.VII.79, pit trap // David Richmond. University of Nebraska State Museum, Lincoln NB – 8: 1 male, 7 females, TX: El Paso Co, red dunes on Montana Ave., 31.841° N 106.131° W, 1245 m, rolling AM after PM rains, 22-VIII-2010, M. J. Paulsen. New Mexico State University Arthropod Collection, Las Cruces NM – 20: NMSUAC Accession Codes (yellow labels): Males (6): 0016583, 0020360, 0020364, 0020371, 0020375, 0020385. Females (14): 0016584, 0020357, 0020359, 0020361, 0020362, 0020365, 0020366, 0020368, 0020370, 0020377, 0020378, 0020384, 0020386, 0020389 Locality Data: 0016583 and 0016584: NM, Doña Ana Co., Jornada Exp. Range, pit trap, vii-14-1989, D. Richman; all others: N. Mex., Doña Ana Co., Jornada Range, 15 m N Las Cruces, 24-vii-79, D. Richman. Paul K. Lago Collection, University MS – 2: one male, one female, Red sands US [Hwy] 62,180, El Paso Co. Tex., Sept. 17, 1985, Coll. G.A. Covert//GAC 1254. Snow Entomological Collections, University of Kansas, Lawrence KS – one male, NM, Albuquerque, VII-5-41, E. L. Todd. Richard A. Cunningham Collection, Show Low AZ – 2 males, N. Mex., Doña Ana Co., Jornada Range, 15 m N of Las Cruces, pit trap, 24 vii 79. Texas A&M University Insect Collection, College Station TX – 22: 7 males, 4 females (same data as holotype) database numbers TAMU-ENTO X 0295573 , 0296014 , 0296864 , 0297061 , 0297466 , 1205379 , 1212529 , 1224107 , 1224300 , 1224163 , 1224681 ; 2 males, 2 females [ex CAS], New Mex. , Torrance Co., Town of Gran Quivara, 6500 ft. alt., 29-viii-1967, Hugh B. Leech, ex vertical tunnel in sandy soil, X 1224343, 1695095, 1699095, 1700596 ; one female [ex MSB], Socorro Co., NM, Sevilletta [sic] sand dunes, 20 April 1982, C. S. Crawford, X 1695695 ; one female [ex MSB], 17 km SW/S Bernardo , N 34.292 W 106.928, 17 July 1998, coll. S.L. Brantley, X 1698174 ; one male [ex MSB], Bernalillo Co., NM, Volcano Cliffs , Alb., 10 Aug 1979, C. S. Crawford, X 1570302 ; one female [ex MSB], NM, Bernalillo Co., Albuquerque , Aug. 2, 1974, B. Blake, X 0012317 ; one male, one female [ex NMSUAC], N. Mex., Doña Ana Co., Jornada Range , 15 m N Las Cruces, 24-vii-79, D. Richman, X 1699292, 1700581 ; one female [ex UNSM], TX: El Paso Co, red dunes on Montana Ave. , 31.841° N 106.131° W, 1245 m, rolling AM after PM rains, 22-VIII-2010, M. J. Paulsen, X 1547783. Total paratypes: 120

Comments. Boreocanthon halffteri is very closely related to B. probus , from which it differs by a) distribution; b) anterolateral pronotal angles conspicuously explanate; c) more elongate parameres; d) rounded shape of paraocular areas; d) somewhat more acute, narrower and widely spaced clypeal teeth. Some specimens of the latter species from eastern New Mexico and adjacent west Texas counties are intermediate between B. halffteri and more “typical” B. probus . They could be considered reasonable grounds for regarding the two taxa as subspecies. However, what I know now suggests that B. halffteri , in addition to being morphologically distinct, is restricted to the Rio Grande drainage and geographically isolated from B. probus , which to me weaken an assumption that they are conspecific. The most proximate populations between the two species are that of B. halffteri in El Paso (El Paso County) and that of B. probus near Monahans (Ward County), Texas, separated by about 200 miles ( Fig. 82 , inset). Of note is the fact that red sands characterize the El Paso site while white sands predominate in those near Monahans. Viewed on Google Earth, the intervening east-west gap between about 31°N and 32° N latitude, where neither species is yet known to occur, appears largely devoid of dune habitat. Whether or not the disjunction is real will be tested by the results of future sampling in that area. Of note is the fact that B. ebenus occurs at both the El Paso and Monahans locations. Schoenly’s (1983) reference to B. melanus on the west slopes of the Hueco Mountains (El Paso County, 31°44 ʹ N 106°04 ʹ W) is likely assignable to this new species; however, his voucher specimens, collected along with B. ebenus , could not be located at Angelo State University, where Schoenly reported depositing them (Serina Brady, pers. comm.).

Figures

Figure 82. Approximate distributions of Boreocanthon probus (Germar) and B. halffteri, new species. Inset depicts recorded collection sites for B. halffteri (solid red circles) and in western Texas for B. probus (solid lavender triangles;? = doubtful site for B. probus, q.v).

Figures 83–89. Boreocanthon halffteri, new species. 83) Holotype male, dorsal view. 84) Holotype male, oblique anterolateral view. 85) Lateral view of genital capsule. 86) Apical view of parameres. 87) Dorsal view of portion of pronotum. 88) Dorsolateral view of elytron (arrow marks carinulate 8th stria). 89) Dorsal view of head margin.

Figures 1–2. 1) Approximate corporate distribution of the genus Boreocanthon. 2) Generalized depiction of vegetation biomes of the United States (Biome key in box; See Materials and Methods for explanation).