Lasioglossum orphnaeum McGinley 1986

Lasioglossum orphnaeum

TYPE MATERIAL.—The female holotype is in the Snow Museum, University of Kansas, Lawrence. It is in excellent condition and is labeled

MEXICO Puebla Apulco (N. of Zacapoaxtla) 4700 ft. 19 June 1961 U. Kans. Mex. Exped./HOLOTYPE Lasioglossum orphnaeum R.J. McGinley [red label].

The one male paratype is in the University of Kansas collection and six female paratypes are deposited in the Michigan State University collection in East Lansing (the paratypes are listed in the “Specimens Examined” section).

ETYMOLOGY.—The specific epithet is derived from the Greek orphnos (dark, dusky), and alludes to the dark-brown mesoscutal hairs characteristic of this species.

DISTRIBUTION (Figure 300).—Lasioglossum orphaneum is presently known from only seven females and one male from the Mexican states of Puebla and Veracruz.

DIAGNOSIS.—Females of L. orphnaeum are the only Mexican Lasioglossum having a strongly striate dorsal propodeal surface (Figure 547). The propodeum of L. perscabrum is highly sculptured but reticulate (Figure 599), not striate. Like L. perscabrum, the mesoscutal punctuation is coarse, nearly contiguous and becomes scabrous along the anterior edge (Figure 548) and the pronotal lateral angle is sharply projecting. Unlike L. perscabrum, the mesoscutal hairs of L. orphnaeum are dark brown (found elsewhere only in L. eickworti and L. katyae, which differ from L. orphnaeum in lacking the strongly sculptured propodeal surface). The pronotal lateral carina appears complete, only obscurely notched by an oblique lateral sulcus (Figure 549).

Lasioglossum citerius, known only from the unique holotype female, which lacks locality data, is probably a Mexican species (see “Distribution” section for L. citerius). It shares with L. orphnaeum the dark mesoscutal hairs, the striate dorsal propodeal surface, and the sharply projecting pronotal angles. Lasioglossum citerius differs from L. orphnaeum in having the anterior median edge of the mesoscutum strongly elevated and bilobed (moderately elevated and weakly bilobed in L. orphnaeum), having large, widely separated mesoscutal punctures posteriorly (Figure 336; compare with Figure 548), and by having a broadly interrupted pronotal lateral carina with the lower portion of the carina broadly rounded and inconspicuous (similar to that of L. pacificum, Figure 12; pronotal carina sharply edged, nearly complete in L. orphnaeum, Figure 549).

The propodeal sculpturing of the one known L. orphnaeum male is similar to that of the female but has fewer striae. The mesoscutal hairs of the male are not so dark as those of the female, and the pronotal lateral carina is conspicuously complete and sharply edged.

DESCRIPTION.—FEMALE: (1) Length 7.8–9.3 mm (x = 8.3, n = 6); (2) wing length 2.3–2.4 mm (x = 2.4, n = 6); (3) abdominal width 2.5–2.8 mm (x = 2.6, n = 6).

Structure: (4) Head short (Figure 545; length/width ratio 0.83–0.91, x = 0.88, n = 6). (7) Supraclypeal area evenly rounded with well-developed frontal carina dorsally, (8) area weakly protuberant. (9) Clypeus projecting approximately 0.68 of its length below lower margin of eyes; (11) surface with obscure median longitudinal sulcation. (14) Distance between lateral ocelli slightly exceeded by distance between lateral ocellus and eye. (23) Flagellomere 1 subequal to 2 in length along dorsal surface. Labrum as in Figure 546; (27) distal keel moderately narrow, lateral edges bowed; (28) distal lateral projections absent; (29) fimbrial setae acutely pointed.

(32) Pronotal lateral angle forming sharply projecting right angle; (33) pronotal lateral ridge nearly complete, obscurely notched by oblique lateral sulcus (similar to L. perscabrum); (34) lower portion of lateral ridge sharply edged. (35) Mesoscutal lip weakly bilobed, (36) moderately elevated from pronotum. (40) Dorsal surface of propodeum about 0.80 the length of scutellum and about 1.5 times the length of metanotum, (41) depressed centrally, (42) posterior margin rounded; (43) propodeal triangle defined medially by a low V-shaped elevation, laterally by distinct carinate rims; (44) lateral carinae well developed, extending nearly to dorsal surface. (45) Tibial spur as in Figure 43.

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

Sculpture: (47) Face shiny, (48) densely and uniformly punctate between ocelli and antennae punctures contiguous. (51) Supraclypeal area obscurely granulate, shiny; (52) punctation sparse. (53) Clypeus granulate basally, apical two-thirds polished; (54) punctures obscure basally, sparse apically, separated by 1–3 times their width. (56) Mesoscutum shiny; (57) punctation as in Figure 548, punctures coarse, contiguous laterally, separated by their width centrally, surface conspicuously scabrous anteriorly. (58) Scutellum with moderately sparse punctation adjacent to median line, punctures 2–3 times their width apart. (63) Dorsal surface of propodeum (Figure 547) strongly striate basally, posterior half rugose, median stria very well developed; (64) surface smooth, not alveolated. (65) Metasomal tergum I moderately shiny; (66) punctation fine, dense, punctures slightly less than their width apart.

Coloration: (71) Wing membrane mostly hyaline, obscurely infuscated apically.

Vestiture: (74) Pubescence of head white on gena and near antennae, becoming brown on vertex. (75) Pubescence of mesoscutum, scutellum dark brown, hairs on metanotum, propodeum and mesopleuron white; (76) mesoscutal hairs moderately dense, conspicuously plumose. (77) Hind tibial hairs concolorous, 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. (81) Unlike most species, basal hair hands narrow, covering at most basal 0.25 of terga.

MALE: Similar to female except as follows: (1) length 7.0 mm (n = 1); (2) wing length 2.2 mm (n = 1); (3) abdominal width 2.0 mm (n = 1). (4) Head short, length/width ratio 0.90 (n = 1). (5) Gena subequal to eye in width, (6) moderately produced posteriorly. (10) Clypeal surface noticeably depressed ventrally. (24) Labral distal process weakly developed, broadly rounded; (25) basal area only faintly depressed medially; (26) basal lateral depressions well developed. (30) Mandible moderately elongate, reaching slightly beyond opposing clypeal angle. (53) Clypeus granulate, shiny; (54) punctation nearly uniform throughout, punctures larger and slightly less dense towards apical edge, absent in apical median depression. (68) Clypeal maculation absent. (69) Flagellum entirely dark. (72) Tarsi dark, concolorous with tibiae.

Vestiture: Sternal vestiture as in Figure 553; (82) hairs on sternum IV moderately short, suberect medially, directed laterally and becoming elongate near lateral edge of sternum; (83) vestiture of sternum V similar to that of sternum IV but with lateral elongate hairs noticeably curled.

Terminalia: Sterna VII–VIII were not available for study. Genitalia as in Figures 550–552; (86) gonobase moderately elongate; (87) gonostylus elongate, gradually increasing in width to bluntly rounded apex; (89) retrorse membranous lobe very short, bulbous; (90) volsella with weakly developed lateral lobe.

FLIGHT RECORDS.—Six of the seven known L. orphnaeum females were collected in early August. The other female and the one known male were taken in late June.

SPECIMENS EXAMINED.—Holotype and seven paratypes (7, 1).

MEXICO. PUEBLA: Apulco (N of Zacapoaxtla), 19 Jun 1961, 4700 ft, Univ. Kansas Mex. Exped. (1, holotype; KU); Chautapehual (N of Zacapoaxtla), 19 Jun 1961, 5300 ft, Univ. Kansas Mex. Exped. (1; KU).

VERACRUZ: Jalapa, 1–6 Aug 1961, R. & K. Dreisbach (6; MSUEL).