Lasioglossum desertum (Smith 1879)

Lasioglossum desertum (Smith)

Halictus desertus Smith, 1879:38 [female, male].—Fox, 1893:14 [locality record: Baja California?].—Dalla Torre, 1896:60 [World catalog].—Cockerell, 1897:164 [taxonomic notes]; 1899:5 [locality record]; 1905b:353 [taxonomic notes].—Sandhouse and Cockerell, 1924:333 [distribution].—Cockerell, 1949:446 [taxonomic notes].

Halictus dersertus.—Dalla Torre, 1896:60 [lapsus calami].

Halictus cyaneiceps Cockerell, 1916a:254 [female, male]; 1930:6 [relationship to H. heterorhinus]. [New synonymy.]

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

Lasioglossum desertum.—Michener, 1954:40 [compared to L. uyacicola].

TYPE MATERIAL.—Smith based his original description of Halictus desertus on a female and male from Oajaca (sic), Mexico. The female lectotype, herein designated, is in poor condition. The hairs on and around the scutellum are soiled and the specimen is missing the following parts: the left antenna; tarsus and tibia of the left foreleg; distal tarsomere of the right foreleg; two distal tarsomeres of the left middle leg; tarsus and femur of the left hind leg; tarsus of the right hind leg. The lectotype, in the British Museum (BMNH), is labeled

Type H.T. [circular label with orange border]/B.M. TYPE HYM. 17.a. 1012/Halictus desertus (Type) Sm. [handwritten]/LECTOTYPE Halictus desertus Smith des.[ignated by] McGinley.

The female holotype of Halictus cyaneiceps, in the National Museum of Natural History, Smithsonian Institution, is in excellent condition except for missing the last tarsomere of the left hind leg. It is labeled

Coll.[ector] Townsend/White Mts[Mountains] 7[Jul] 31 NM[New Mexico]/Rio Ruidoso [Lincoln County] Abt[about] 6500ft/On fls[flowers of] Heliopsis scabra/Type No. 20407 U.S.N.M.[red label]/Halictus cyaneiceps Ckll.[Cockerell] TYPE [handwritten by Cockerell].

Four female paratypes have been located: two in the National Museum of Natural History, one in the Canadian National Collection, and one in the University of California, Berkeley.

DISTRIBUTION (Figure 302).—Lasioglossum desertum occurs throughout the Rocky Mountain system as far north as Musselshell County, Montana, south to the state of Oaxaca, Mexico. Most specimens, however, have been collected in Arizona, Colorado, and New Mexico. Label data often includes elevation information with figures ranging from 5400 to 8750 feet. One male, possibly mislabeled, was collected from Murray County, Oklahoma (University of Kansas Collection).

DIAGNOSIS.—The short head (Figure 381; length/width ratio 0.78–0.92, x = 0.86), hyaline wing membranes and presence of an acarinarium on the anterior surface of metasomal tergum I (Figure 393) will separate female L. desertum from other Lasioglossum species except L. bardum and L. jubatum. Lasioglossum jubatum also has an extremely wide dorsal acarinarial opening (Figure 478), which differs from the relatively narrow opening found in L. bardum (Figure 307). Lasioglossum jubatum can be easily recognized by the deep golden to pale ferrugineous mesoscutal pubescence (white in L. desertum). Lasioglossum acarophilum (from Mexico and southern Arizona) and L. uyacicola (from Chiapas, Mexico to Panama) also have very wide dorsal acarinarial openings but have relatively elongate heads (Figures 246, 724) and mesoscuta that are completely granuloso-punctate and doubly-punctate (Figures 251, 727), differing from the relatively sparse punctation on the posterior half of the L. desertum mesoscutum (Figure 386).

Males of L. desertum, like those of L. heterorhinum and L. lampronotum, have conspicuously broad heads (Figures 382, 459, 487). The latter two species have complete pronotal lateral carinae, whereas that of L. desertum is distinctly interrupted. The hair lobes on the posterior edge of sternum V are only narrowly separated medially (Figure 387; compare with those of L. heterorhinum, Figure 464). Furthermore, the gonostyli of L. heterorhinum and L. lampronotum are only moderately elongate (Figure 468) differing from the conspicuously elongate gonostylus of L. desertum (Figure 391).

DESCRIPTION.—FEMALE: (1) Length 7.4–9.9 mm (x = 8.6, n = 20); (2) wing length 2.3–2.6 mm (x = 2.5, n = 20); (3) abdominal width 1.8–2.9 mm (x = 2.6, n = 20).

Structure: (4) Head short (Figure 381; length/width ratio 0.78–0.92, x = 0.86, n = 20). (7) Supraclypeal area evenly rounded, (8) very weakly protuberant. (9) Clypeus projecting approximately 0.71 of its length below lower margin of eyes; (11) surface without median longitudinal sulcation. (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 383; (27) distal keel broad in frontal view, somewhat spoon-shaped; (28) distal lateral projections well developed, triangular, and sharply pointed; (29) fimbrial setae acutely pointed.

(32) Pronotal lateral angle broadly obtuse; (33) pronotal lateral ridge incomplete, interrupted by oblique lateral sulcus; (34) lower portion of lateral ridge narrowly rounded. (35) Mesoscutal lip weakly bilobed, (36) moderately elevated from pronotum. (40) Dorsal surface of propodeum about 0.76 the length of scutellum and about 1.3 times the length of metanotum, (41) slightly depressed centrally, (42) posterior margin broadly rounded; (43) propodeal triangle weakly defined, median V-shaped area inconspicuous, lateral rims absent; (44) lateral carinae extending less than half the length of posterior surface. (45) Tibial spur as in Figure 30.

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

Sculpture: (47) Face shiny, (48) densely punctate below ocelli, punctures contiguous, becoming only slightly larger and less dense near antennae. (51) Supraclypeal area extremely granulate, (51) uniformly punctate, punctures 1–2 times their width apart. (53) Clypeus granulate basally, apical half polished; (54) punctures somewhat obscure, nearly contiguous basally, larger and less dense apically, apicolateral areas sparsely punctate. (56) Mesoscutum shiny; (57) punctation as in Figure 386, punctures separated by their width or less laterally, becoming granulopunctate anteriorly, less dense centrally, punctures separated by 1–4 times their width. (58) Scutellum sparsely punctate adjacent to median line, punctures 1–3 times their width apart. (63) Dorsal surface of propodeum (Figure 385) ruguloso-striolate, striae obscurely reaching posterior margin; (64) surface alveolated. (65) Metasomal tergum I moderately shiny; (66) punctation fine, dense, punctures slightly less than their width apart.

Coloration: (71) Wing membrane hyaline.

Vestiture: (74) Pubescence of head white. (75) Pubescence of thorax white; (76) mesoscutal hairs moderately dense, conspicuously 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 present (Figure 393), a large circular, glabrous area at base of tergum I, surrounded laterally and dorsolaterally by elongate hair fringes, dorsal opening of acarinarium wide, opening slightly wider than width of lateral hair fringe as seen in dorsal view.

MALE: Similar to female except as follows: (1) length 6.4–8.1 mm (x = 7.4, n = 20); (2) wing length 1.8–2.3 mm (x = 2.1, n = 20); (3) abdominal width 1.6–2.1 mm (x = 1.8, x = 20). (4) Head as in Figure 382 (length/width ratio 0.76–0.95, x = 0.86, n = 20). (5) Gena subequal to eye in width, (6) moderately produced posteriorly. (10) Clypeal surface shallowly depressed ventrally. Labrum as in Figure 384; (24) distal process absent; (25) basal area depressed medially; (26) basal lateral depressions absent. (30) Mandible short, just reaching opposing clypeal angle. (53) Clypeus polished; (54) punctures well formed and dense basally, very fine and scattered over apical two-thirds. (68) Clypeal maculation present. (69) Flagellum pale yellowish orange ventrally, strongly contrasting with dark dorsum or entirely dark. (72) Tarsi dark, concolorous with tibiae.

Vestiture: Sternal vestiture as in Figure 387; (82) hairs on sternum IV elongate, erect; (83) sternum V without conspicuous erect hairs, posterior edge of sternum with broadly rounded, moderately elongate and narrowly separated lateral adpressed hair lobes.

Terminalia: Sterna VII–VIII as in Figure 392; (85) sternum VIII with extremely elongate, slender median process, slightly broader apically than along stem. Genitalia as in Figures 388–391; (86) gonobase moderately elongate; (87) gonostylus extremely elongate and slender; (89) retrorse membranous lobe slender; (90) volsella with prominent lateral lobe.

FLIGHT RECORDS (Figure 394).—Lasioglossum desertum females have been collected from late March through early November, with most records (82%) from June through August, with a peak in late July. The March and September records are from southern Arizona. The two October records are from San Luis Potosi and Jalisco, Mexico; the November record from Pima County, Arizona. Most males have been collected in August but records range from June through September.

FLOWER RECORDS.—Females (38): Cucurbitaceae 13%; Scrophulariaceae 13%; Compositae 11%. Males (34): Compositae 71%; Labiatae 24%. Total: 72 in 18 families, 28 genera as follows:

Arctostaphylos 1; Aster 22; Baccharis 1; Ceanothus 3; Cucurbita 1; Engelmannia 1; Erigeron 1; Geranium 2, 2; Heliopsis 2; Heterotheca 1; Ipomoea 2; Iris 1(1); *Malvastrum 1(1); Marrubium 1; *Melilotus 2(1); Monarda 8; Penstemon 2; Physocarpus 2; *Pulsatilla 1(1); Rhus 1; Rubus 1; *Salix 1(1); Schinus 1; Sicyos 4; Sisyrinchium 1; Sphaeralcea 2; Verbascum 3; Vitis 1.

Lasioglossum desertum là một loài Hymenoptera trong họ Halictidae. Loài này được Smith mô tả khoa học năm 1879.