Veromessor smithi, Cole, 1963

Johnson, Robert A., Borowiec, Marek L., Snelling, Roy R. & Cole, Arthur C., 2022, A taxonomic revision and a review of the biology of the North American seed-harvester ant genus Veromessor (Hymenoptera: Formicidae: Myrmicinae), Zootaxa 5206 (1), pp. 1-115 : 86-88

Veromessor smithi

( Figures 1I , 6D , 45–47 )

Distribution— Figure 40C

Veromessor smithi Cole, 1963: 678 , figs. 1a, 2a, 3a (worker, queen, male). Holotype worker [LACM: LACMENT164497]: UNITED STATES, Nevada: Nye County, Nevada Test Site, Area 12 desert near Mercury, 3300’, 15 July 1962 (A.C. Cole NEV-721). Additional paratype series from same locality, 15 July 1962 —A.C. Cole NEV-722: LACM (3 workers, 3 alate queens, 6 males): 17 July 1962 —A.C. Cole NEV-739: USNM (101 workers, 7 alate queens, 1 dealate queen, 4 males); 4 July 1962 —A.C. Cole NEV-741: LACM (4 workers, 3 alate queens, 1 male), UAIC (4 workers); 20 June 1962 —A.C. Cole NEV-744: LACM (6 workers); 20 Jun 1962 —A.C. Cole NEV-745: LACM (6 workers); 20 June 1962 —A.C. Cole NEV-757: LACM (1 worker, 1 alate queen, 1 male); 20 June 1962 —A.C. Cole NEV-758: LACM (3 workers, 3 alate queens, 3 males); 23 Jun 1962 —A.C. Cole NEV-759: LACM (4 workers, 1 alate queen, 1 male). See also Wheeler and Wheeler, 1972: 240 (larvae).

Messor smithi (Cole) ; Bolton, 1982: 341 (first combination in Messor ).

Veromessor smithi Cole ; Ward, Brady, Fisher, and Schultz 2015: 13 (revived combination in Veromessor ).

W orker diagnosis. This species is uniquely characterized by the following combination of features: (1) yellowishred or dull reddish to reddish-brown, (2) medial lobe of clypeus smooth and shining, sometimes with rugae anterad, medial lobe not thick and protuberant in profile, not elevated above lateral lobes in frontal view, anteromedial margin often sharply depressed, (3) mandibles with 8, or rarely 9 teeth, (4) dorsal base of scape flattened and notably widened; maximum basal width of scape greater than maximum preapical width, (5) MOD less than to greater than OMD, OI> 24.5, (6) cephalic dorsum with prominent, wavy, longitudinal rugae that diverge toward posterior corners, rugae posterior to eyes usually becoming more irregular, often with short lateral branches, rugae sometimes fading or disappearing along posterior margin, becoming punctulate-granulate; interrugae on cephalic dorsum weakly coriarious or weakly granulate, weakly shining, (7) psammophore moderately well developed; ventral surface of head capsule with both J-shaped hairs and straight or evenly curved hairs, J-shaped hairs arranged in a V-shaped row which does not reach the posterior part of the lateroventral margin of the head capsule, (8) dorsum of pronotum with strongly irregular rugae to rugoreticulate, interrugae weakly to strongly coriarious or weakly granulate; sides of pronotum with strongly irregular rugae to weakly rugoreticulate, interrugae strongly granulate; mesonotum with strongly irregular longitudinal trending rugae to rugoreticulate; mesopleura with strongly irregular rugae to rugoreticulate dorsad, rugae mostly longitudinal ventrad, interrugae granulate, (9) propodeal spines triangular, acuminate; length less than to sometimes approaching the distance between their bases; infraspinal facet and propodeal declivity weakly sculptured, strongly shining, and (10) metasternal process small, more of less coniform, about as long as high, apex acuminate to bluntly subangulate ( Figures 6D , 45 ).

Measurements. holotype (n = 8 + 24 paratypes). HL 1.50 (1.33–1.58); HW 1.50 (1.33–1.61); MOD 0.47 (0.38– 0.49); OMD 0.44 (0.32–0.48); SL 1.40 (1.23–1.44); PNW 0.92 (0.81–1.01); HFL 1.59 (1.38–1.77); ML 2.11 (1.76– 2.07); PW 0.29 (0.25–0.31); PPW 0.47 (0.37–0.46). Indices: SI 93.33 (84.83–98.50); CI 100.00 (97.79–108.27); OI 31.33 (24.84–33.57); HFI 106.00 (95.83–116.43).

Queen diagnosis. This caste is diagnosed by the following combination of features: (1) light ferruginous orange to orangish-red, gaster sometimes light orangish-brown, (2) medial lobe of clypeus mostly smooth and shining or rarely with irregular rugae, medial lobe not thick and protuberant in profile, not elevated above lateral lobes in frontal view, (3) mandibles with 8 teeth, (4) dorsal base of scape flattened and widened; maximum basal width of scape greater than maximum preapical width, (5) MOD slightly greater than OMD, (6) cephalic dorsum with longitudinal rugae that diverge toward posterior corners with rugae usually weakening to disappearing posterior to ocelli, weakly punctate-granulate, weakly shining; interrugae on cephalic dorsum weakly punctulate, weakly shining, (7) psammophore moderately well developed, (8) mesocutum and mesoscutellum smooth and shining with scattered piligerous punctures; anepisternum weakly shining and densely punctate between longitudinal rugae; katepisternum shinier, with weaker rugae or mostly granulate, but usually smooth and arugose anteroventrally, (9) propodeum with weak irregular longitudinal and oblique rugae; propodeal spines triangular, acuminate, length about the same as width at base; length much less than distance between their bases; interspinal surface and propodeal declivity weakly coriarious, shining, and (10) metasternal process small, more or less coniform, about as long as high, apex acuminate to bluntly subangulate ( Figure 46 ).

Measurements. (n = 8 + 4 paratypes). HL 1.40–1.63; HW 1.43–1.69; MOD 0.41–0.48; OMD 0.30–0.45; SL 1.20–1.42; HFL 1.55–1.82; ML 2.06–2.38; PW 0.28–0.36; PPW 0.57–0.57. Indices: SI 82.99–93.75; CI 97.30– 106.25; OI 26.04–33.33; HFI 103.33–119.44.

Male diagnosis. This caste is diagnosed by the following combination of features: (11) yellowish-brown to light medium brown, (12) medial lobe of clypeus abruptly depressed across anterior margin, anterior margin straight across middle, (13) preapical tooth small; mandibles with one or two minute denticles or teeth basad of preapical tooth, (14) anterior ocellus above level of top of eyes, (15) mesopleura very weakly sculptured, but anepisternum usually punctulate and with some widely spaced, very fine rugae; katepisternum mostly smooth and shining to weakly roughened, (16) propodeum weakly sculptured with some widely spaced, longitudinal rugae; spines or denticles absent; in profile, juncture of dorsal surface and propodeal declivity rounded to subangulate, (17) metasternal process elongate, slender, often with a withered look, and (18) subpetiolar process short, triangular to spine-like ( Figures 1I , 47 ).

Measurements. (n = 5 + 7 paratypes). HL 0.77–0.91; HW 0.68–0.75; MOD 0.34–0.41; OMD 0.08–0.11; SL 0.23–0.36; HFL 1.42–1.75; ML 1.91–2.29; PW 0.26–0.31; PPW 0.39–0.51; AOD 0.09–0.12; IOD 0.23–0.30; OOD 0.19–0.27. Indices: SI 31.04–50.00; CI 80.23–90.91; OI 49.28–60.29; HFI 201.33–247.14.

Additional material examined. UNITED STATES: Arizona: Apache Co. : Carrizo Mtns at Black Rock Dike, 2033 m, Jun 12, 2009 (MCZC); Carrizo Mts at Red Goat Wash, 1724 m, Jun 5, 2009 (MCZC). Coconino Co.: 32 km W Cameron on old Rt 64, 1746 m, Jul 28, 2011 (MCZC). Mohave Co.: 4 mi NW Nixon Springs, Aug 5, 1969 (LACM). Yavapai Co.: Prescott National Forest, USFS Rd 680 at 0.4 mi E Hwy 89 & 7.1 mi N Paulden, 4850’, Mar 10, 1993 & Apr 20, 1999 & Jul 25, 1999 (RAJC; UCDC). California: Inyo Co. : 4.8 mi SW Independence, 5580’, May 24, 2008 (RAJC). Lassen Co.: 6 km SE Wendel, 1230 m, Jul 7, 2002 (UCDC). Colorado: Huerfano Co.: 3 mi N Walsenburg, Aug 26, 1951 (LACM). Nevada: Esmeralda Co. : 20 mi WNW Tonapah, 4800’, Jun 19, 1970 (LACM); 4 mi NW Pigeon Spring, 6100’, May 28, 1970 (RAJC); Lida Junction, 4800’, no date (not examined; see Wheeler & Wheeler, 1986); 1.4 mi E Lida, 5910’, Jun 16, 2020 (RAJC). Eureka Co.: 5 mi SSW Beowawe, 4500’, Jul 2, 1971 (RAJC). Humboldt Co.: 3 mi SSW Denio, 5200’, Apr 2, 1970 (RAJC). Lander Co.: Big Smoky Valley (T17N, R45E, Sect 6), 6100’, May 3, 1971 (RAJC). Lincoln Co.: 6 mi E Panaca, 5800’, no date (not examined; see Wheeler & Wheeler, 1986); 4 mi W Caliente, 5600’, no date (not examined; see Wheeler & Wheeler, 1986); 10 mi SW Crystal Springs, 5500’, no date (not examined; see Wheeler & Wheeler, 1986). Lyon Co.: 8 mi SSE Yerington, 4600’, May 20, 1971 (RAJC); 16 rd mi SSE Yerington, 5200’, Jun 16, 1979 (LACM); Pine Grove Rd at 10.6 mi S Jct Hwy 208, 5200’, Jul 23, 2018 (NHMW; RAJC); 7 km SW Silver Springs, 1380 m, Sep 29, 1993 (RAJC); Churchill Butte, 6000’ & 1830 m, Jun 11, 1975 & Jul 3, 1994 (RAJC; UCDC). Mineral Co.: Dead Horse Wells, 4100’, no date (not examined; see Wheeler & Wheeler, 1986); Petrified Summit, 6200’, no date (not examined; see Wheeler & Wheeler, 1986). Nye Co.: Hot Creek Valley at 10 mi NE Warm Springs, 5200’, no date (not examined; see Wheeler & Wheeler, 1986); 6 mi E Tonopah, 5600’, no date (not examined; see Wheeler & Wheeler, 1986). Storey Co.: Clark Mine at 27 km E Sparks, 1420 m, May 24, 1994 (not examined; M. Bennett, pers. comm.); 20 km WSW Fernley, 1430 m, Jul 3, 1994 (UCDC). New Mexico: San Juan Co.: Carrizo Mtns at Arnold Cliff Ranch, 1824 m, Aug 20, 2010 (MCZC). Oregon: Malheur Co.: Jct Hwys 95 & 78, no date (LACM) ( Figure 41C ).

Etymology. This species was named after Dr. M.R. Smith, who spent numerous years dedicated to the meticulous study of ants.

Discussion. Veromessor smithi is broadly sympatric with several congeners including V. lobognathus , V. lariversi , and V. pseudolariversi . Workers of Veromessor smithi are separated from V. lobognathus based on: (1) propodeal spines short, length less than distance between their bases and length <0.5× MOD, (2) eyes larger (MOD = 0.38–0.49, OI = 24.8–33.5), and (3) area between eyes and frontal lobes weakly coriarious and weakly shining to shining between faint to prominent weakly irregular to regular rugae. In V. lobognathus : (1) propodeal spines longer, length greater than distance between their bases and length> 1.0× MOD, (2) eyes smaller (MOD = 0.31–0.41, OI = 20.5–25.0), and (3) area between eyes and frontal lobes strongly granulate and dull between prominent strongly irregular rugae to weakly rugoreticulate.

Workers of Veromessor smithi are separted from V. lariversi and V. pseudolariversi by: (1) larger in size (HW = 1.33–1.61 mm), (2) concolorous orangish-brown to rust colored, (3) maximum basal width of scape greater than maximum preapical width, and (4) mandibles with 8, or rarely 9 teeth. For V. lariversi and V. pseudolariversi : (1) smaller in size (HW = 0.93–1.37 mm), (2) body concolorous light yellowish to yellowish-orange or yellowishred, gaster often slightly darker, (3) maximum basal width of scape less than maximum preapical width, and (4) mandibles with 7 teeth.

The type locality for V. smithi is the Nevada Test Site in Area 12 (= Rainier Mesa), which is along the northern edge of the Nevada Test Site .

A molecular phylogeny that used UCEs shows V. smithi and V. lobognathus are sister lineages (M.L. Borowiec, unpub. data).

Biology. Little is known about the biology of V. smithi . Workers are solitary, crepuscular and nocturnal foragers ( Cole, 1963; 1966; M. Bennett, pers. comm.). Nests are placed in open, exposed areas and typically consist of one to two small circular craters about 10–15 cm in diameter ( Cole, 1966). Colonies are small, with one excavated colony containing 275 workers, 1 dealate queen, 27 alate queens, and 97 males ( Cole, 1963).

Gland chemistry has not been examined in V. smithi . Like other small-colony congeners, workers of V. smithi have a small pygidial gland reservoir and lack a textured tergal cuticle ( Hölldobler et al., 2013).

Mating flights have not been observed, but sexuals have been collected in nests from 12 Jun–27 July ( Cole, 1966), suggesting that mating flights occur during late June–July. One dealate brachypterous queen was also examined by RAJ (RAJC; Wheeler and Wheeler NEV#1709).

Veromessor smithi occurs at elevations from 760–2,275 m. It appears to be most common in pinyon pine-juniper habitats similar to those inhabited by V. lobognathus . Collections from southwestern Oregon, northwestern New Mexico, and southcentral Colorado indicate that V. smithi is much more widely distributed than indicated by current records, and it also likely occurs in Utah and western Colorado. This species occurs in the Great Basin shrub steppe, Snake–Columbia shrub steppe, Colorado Plateau shrublands, Arizona Mountains forests, Western short grasslands, and Mohave desert ecoregions, as defined by Olson et al. (2001); the two Mohave desert records are from midelevations ( Figure 41C ).

Figures

FIGURE 1. Photographs of the metasternal process on males of Veromessor: (A) V. andrei (CASENT4010823), (B) V. chamberlini (UCRC_ENT00500152), (C)V.chicoensis (CASENT0869853), (D) V.julianus (LACMENT359792),(E)V.lariversi (CASENT0761204), (F) V. lobognathus (LACMENT363986), (G) V. pergandei (CASENT0869850), (H) V. pseudolariversi (CASENT0869851), (I) V. smithi (LACMENT364071), and (J) V. stoddardi (LACMENT364102). Photographs by Robert Johnson from www.AntWeb.org.

FIGURE 6. Photographs of the four categories of increasing psammophore development for species of Veromessor based on number and distribution of long J-shaped hairs on the ventral surface of the head capsule (= hypostomal region) (see text). Photograph of: (A) V. chicoensis (CASENT0923125)—J-shaped hairs mostly absent with scattered straight or evenly curved hairs, (B) V. andrei (CASENT0923140)—J-shaped hairs present but not arranged in a distinct row, usually mixed with straight or evenly curved hairs, (C) V. chamberlini (CASENT0761101) and (D) V. smithi (CASENT0923131)—J-shaped hairs present, arranged in a V-shaped row which does not reach the posterior part of the lateroventral margin of head capsule, usually mixed with straight or evenly curved hairs, and (E) V. pergandei (CASENT0923124)—J-shaped hairs present, many long J-shaped hairs arranged in a distinct row around the outer margin of the ventral region of the head capsule. Photographs by Wade Lee from www.AntWeb.org.

FIGURE 40. Photograph of Veromessor pergandei male: (A) frontal view of head, (B) lateral view of body, and (C) dorsal view of body (CASENT0922828). Photographs by Michele Esposito from www.AntWeb.org.

FIGURE 41. Geographic distribution of: (A) Veromessor pergandei, (B) V. pseudolariversi, and (C) V. smithi. The larger black circle in panels B & C denotes the type locality.

FIGURE 45. Photograph of Veromessor smithi worker: (A) frontal view of head, (B) lateral view of body, and (C) dorsal view of body (MCZ-ENT00671466). Photographs by Wade Lee from www.AntWeb.org.

FIGURE 46. Photograph of Veromessor smithi alate queen: (A) frontal view of head, (B) lateral view of body, and (C) dorsal view of body (MCZ-ENT00671476). Photographs by Wade Lee from www.AntWeb.org.

FIGURE 47. Photograph of Veromessor smithi paratype male: (A) frontal view of head, (B) lateral view of body, and (C) dorsal view of body (LACMENT364058). Photographs by Michele Esposito from www.AntWeb.org.