Lasioglossum heterorhinum (Cockerell 1930)

Lasioglossum heterorhinum (Cockerell)

Halictus heterorhinus Cockerell, 1930:6 [female].

Lasioglossum heterorhinum.—Michener, 1951:1106 [Nearctic catalog].—Hurd, 1979:1957 [Nearctic catalog].

TYPE MATERIAL.—The female holotype, in the American Museum of Natural History, is labeled

Mesa Verde [Montezuma County], Colo, [rado] July 3–7, [19]'19 F4370F [?]/About 37°12′ N.[orth] “[about] 108°29′ W.[est]” [about] 7300 ft.[feet]/Halictus heterorhinus Ckll. [Cockerell] TYPE [handwritten by Cockerell]

The specimen is missing the right antenna and the tibia and tarsus of the hind left leg but otherwise is in excellent condition. No paratypes were designated by Cockerell.

DISTRIBUTION (Figure 457).—Lasioglossum heterorhinum is found through portions of the Rocky Mountain system and the Black Hills, south into Mexico. Many specimens are associated with elevation data that range from 4300 to 9000 feet. In the United States this species is now known from Arizona, Colorado, Nevada, New Mexico, South Dakota, and Utah. Two females in the Oregon State Collection were collected in Hidalgo, Mexico. They appear to be conspecific with the northern specimens, apparently differing only by their darker scopal hairs. Also appearing conspecific is one male collected in Veracruz (Utah State University). Future collecting in the mountainous areas of northern and central Mexico will probably produce more specimens of this species.

DIAGNOSIS.—Lasioglossum heterorhinum can be recognized by the following unique character combination: pronotal lateral carina complete, not interrupted by oblique sulcus (as in Figure 9); mesoscutum dull, granuloso-punctate on anterior half, punctures less dense and surface shiny on posterior half (Figure 463); acarinarium absent, elongate, dense hairs scattered over anterior surface of metasomal tergum I; head short (Figure 458, length/width ratio 0.76–0.92, x = 0.86); basal half of clypeus conspicuously granulate, contrasting with polished apical half; wing membranes pale yellowish brown.

In the United States, only two other species have a complete pronotal lateral carina, L. lampronotum and L. channelense (carina actually microscopically notched, Figure 100). The mesoscutum of L. lampronotum is very shiny throughout, not dull, granuloso-punctate on the anterior half. Lasioglossum lampronotum also has a completely polished clypeus (not granulate basally), hyaline wing membranes (not pale yellowish brown), and pale yellowish orange hind legs (usually dark brown in L. heterorhinum). Lasioglossum channelense, known only from the Channel Islands of California, is easily differentiated by its relatively elongate head (Figure 319) and metasomal acarinarium (Figure 330). Lasioglossum rupticristum is very similar to and sympatric with L. heterorhinum but has an incomplete pronotal lateral carina, hyaline wings, and an entirely polished clypeus.

A number of Mexican Lasioglossum species have complete pronotal lateral carinae but differ from L. heterorhinum in details of mesoscutal or propodeal sculpture, or by having acarinaria or elongate heads. Lasioglossum argutum is the most similar Mexican species to L. heterorhinum but can be recognized by its distinctive dorsal propodeal surface, which is highly polished and shiny on the posterior half.

The males of L. heterorhinum and L. lampronotum can be recognized by their broad heads (Figures 459, 487), complete pronotal lateral carina (as in Figure 9), and characteristic hair lobes on the posterior edge of sternum V (Figure 464; these lobes are more widely separated than those of L. desertum, Figure 387). Lasioglossum heterorhinum differs from L. lampronotum by having dark brown tarsi (yellowish white in L. lampronotum), and like the females, having the anterior portion of the mesoscutum granulosopunctate (punctures distinctly separated in L. lampronotum).

DESCRIPTION.—FEMALE: (1) Length 7.5–9.0 mm (x = 8.5, n = 15); (2) wing length 2.4–2.8 mm (x = 2.6, n = 15); (3) abdominal width 2.5–2.9 mm (x = 2.7, n = 15).

Structure: (4) Head short (Figure 458; length/width ratio 0.76–0.92, x = 0.86, n = 15). (7) Supraclypeal area evenly rounded, (8) weakly protuberant. (9) Clypeus projecting approximately 0.64 of its length below lower margin of eyes; (11) surface with obscure median longitudinal sulcation present in most specimens (weakly developed or obscured by punctures in some). (14) Distance between lateral ocelli subequal to distance between lateral ocellus and eye. (23) Flagellomere 1 slightly shorter than 2 along dorsal surface. Labrum as in Figure 460; (27) distal keel moderately broad in frontal view, lateral edges bowed; (28) distal lateral projections weakly developed, rounded; (29) most fimbrial setae bluntly pointed.

(32) Pronotal lateral angle narrowly obtuse; (33) pronotal lateral ridge complete, obscure oblique lateral sulcus reaching ridge but not distinctly interrupting it; (34) lower portion of lateral ridge sharply edged. (35) Mesoscutal lip weakly bilobed, (36) moderately elevated from pronotum. (40) Dorsal surface of propodeum about 0.78 the length of scutellum and about 1.3 times the length of metanotum, (41) very slightly depressed centrally, (42) posterior margin broadly rounded; (43) propodeal triangle weakly defined, evident medially as a low V-shaped elevation with low lateral rims, fading towards metanotum; (44) lateral carinae extending at most to midpoint of posterior surface. (45) Tibial spur as in Figure 34.

(46) Lateral edge of metasomal tergum II weakly sinuate.

Sculpture: (47) Face moderately shiny, (48) densely and uniformly punctate between ocelli and antennae, punctures contiguous. (51) Supraclypeal area extremely granulate; (52) uniformly punctate, punctures separated by 1–3 times their width. (53) Clypeus strongly granulate basally, apical half polished; (54) punctation obscure, virtually absent apicolaterally. (56) Mesoscutum mostly shiny, dull anteriorly; (57) punctation as in Figure 463, punctures extremely dense laterally, contiguous, becoming granuloso-punctate anteriorly, relatively sparse centrally, punctures less dense anteriorly adjacent to median line, separated by their width. (58) Scutellum granuloso-punctate posteriorly, punctures less dense anteriorly adjacent to median line, separated by width. (63) Dorsal surface of propodeum (Figure 462) mostly rugulose, ruguloso-striolate on extreme lateral edges, striae and rugulae reaching posterior margin; (64) surface obscurely alveolated. (65) Metasomal tergum I moderately shiny; (66) punctation fine, extremely dense, punctures nearly contiguous.

Coloration: (71) Wing membrane very pale yellowish brown.

Vestiture: (74) Pubescence of head white. (75) Pubescence of thorax white; (76) mesoscutal hairs moderately dense and plumose. (77) Hind tibial hairs concolorous, pale yellowish brown. (78) Anterior hairs of metasomal tergum I and (79) basal hair bands of terga II–IV white. (80) Acarinarium absent, elongate hairs scattered over anterior surface of tergum I.

MALE: Similar to female except as follows: (1) length 7.0–8.6 mm (x = 7.7, n = 2); (2) wing length 2.1–2.6 mm (x = 2.4, n = 15); (3) abdominal width 1.8–2.6 mm (x = 2.2, n = 15). (4) Head as in Figure 459 (length/width ratio 0.77–0.92, x = 0.86, n = 15). (5) Gena conspicuously wider than eye; (6) strongly produced posteriorly. (10) Clypeal surface shallowly depressed ventrally. Labrum as in Figure 461; (24) distal process developed as an elongate, acute projection; (25) basal area only moderately depressed medially; (26) basal lateral depressions well developed. (30) Mandible moderately elongate, reaching slightly beyond opposing clypeal angle. (53) Clypeus granulate along basal edge, apical two-thirds polished; (54) punctation somewhat uniform throughout, punctures over apical two-thirds slightly less dense than basal punctures. (68) Clypeal maculation present (Figure 459). (69) Flagellum entirely dark or only slightly paler ventrally than on dorsum. (72) Tarsi dark, concolorous with tibiae.

Vestiture: Sternal vestiture as in Figure 464; (82) hairs on sternum IV moderately elongate, suberect; (83) sternum V with a median rosette of short hairs, posterior edge of sternum with broadly rounded and widely separated lateral hair lobes.

Terminalia: Sterna VII–VIII as in Figure 470; (85) sternum VIII with elongate, slender median process, process parallel-sided or with apex slightly broader than stem. Genitalia as in Figures 465–469; (86) gonobase moderately elongate; (87) gonostylus extremely broad and membranous basally, forming a basal collar as in Figure 468, abruptly tapering to a short, narrowly rounded apical portion (in some specimens the entire gonostylar area is highly convoluted and apparently distorted as in Figure 469); (89) retrorse membranous lobe very slender (unlike other species, except L. lampronotum, apex of gonocoxite near base of retrorse lobe conspicuously hairy); (90) volsella with prominent lateral lobe.

FLIGHT RECORDS (Figure 471).—Females of L. heterorhinum have been collected from March through October, with most records from late June. All of the March records are from Cochise Co., Arizona; the September and October records, also from Arizona, are from Cochise and Santa Cruz counties. Most male records are from April but range from February (Veracruz, Mexico) to June.

FLOWER RECORDS.—Females (53): Compositae 47%; Rosaceae 17%. Total: 53 in 13 families, 17 genera as follows:

*Arctostaphylos 1(1); *Asclepias 1(1); Atriplex 2; Berberis 3; Brassica 1; Ceanothus; 1; *Cercocarpus 1(1); *Cimicifuga (1) (collecting pollen, O. Pellmyr, pers. comm.); Erigeron 27; Geranium 1; Pentstemon 3; *Phacelia 1(1); *Potentilla (1); Purshia; 2; Ranunculus 2; *Salix 3(2); Trifolium 2.

SPECIMENS EXAMINED.—201 (182, 19).

MEXICO. HIDALGO: Laredo Highway (Baranca de San Vicente), 9 Aug 1957, 7000 ft, R.M. Straw, D.P. Gregory (2; OrS). VERACRUZ: Perote, 5 mi SW, 29 Feb 1972, F. Parker, D. Miller (1; USU).

UNITED STATES. ARIZONA: Cochise Co.; Coconino Co.; Gila Co.: Parker Creek (Sierra Ancha), Workman Creek; Graham Co.: Graham Mountains; Mohave Co.: Hualapi Mountain Park (14 mi SE Kingman); Navajo Co.: Kayenta; Pima Co.: Santa Catalina Mountains; Santa Cruz Co.: Madera Canyon (Santa Rita Mountains), Mt. Wrightson. COLORADO: Boulder Co.: Boulder; El Paso Co.: Manitou; La Plata Co.: Arboles; Larimer Co.; Las Animas Co.: Starkville; Mesa Co.: Mud Springs; Moffat Co.: Dinosaur, 12 mi N; Montezuma Co.: Mesa Verde; Montrose Co.: Buckeye Reservoir. NEVADA: Humboldt Co.: Winnemuca. NEW MEXICO: Catron Co.: Bursum Camp (18 mi E Alma); Grant Co.: Silver City, 14 mi N, Willow Creek area (Gila National Forest); Otero Co.: Cloudcroft; Rio Arriba Co.: Lake Burford; Sandoval Co.: Jemez Springs; San Miguel Co.: Pecos; Santa Fe Co.: Hyde State Park (8 mi NE Santa Fe), Santa Fe; Socorro Co.: Bear Trap Camp (28 mi SW Magdalena); Torrance Co.: Tajique. SOUTH DAKOTA: Custer Co.: Custer State Park; Pennington Co.: Black Hills, Spring Creek Camp (11 mi NE Hill City). UTAH: Cache Co.: Logan Canyon; Garfield Co.: Bryce National Park (Rim Road), Lonesome Beaver (Henry Mountains), Red Canyon Camp (11 mi SE Panguitch); Grand Co.: Moab, 10 mi SE; Wayne Co.: Hanksville, 24 mi S (Henry Mountains); Weber Co.: Ogden.

Lasioglossum heterorhinum là một loài Hymenoptera trong họ Halictidae. Loài này được Cockerell mô tả khoa học năm 1930.