Lasioglossum bardum (Cresson 1872)

Lasioglossum bardum (Cresson)

Halictus bardus Cresson, 1872:251 [female].—Dalla Torre, 1896:55 [World catalog].—Cockerell, 1897:163, 165 [locality and flower records, taxonomic notes]; 1898a:46 [key]; 1898c:51 [taxonomic notes]; 1906:294 [locality record]; 1916a:254 [taxonomic notes].—Cresson, 1916:107 [lectotype designation].

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

Lasioglossum bardus.—Moldenke and Neff, 1974:52 [distribution and floral records; incorrectly reported from Arizona, California, and New Mexico].

TYPE MATERIAL.—Cresson's original description of Halictus bardus was based on two female syntypes from the Belfrage collection. Cresson later (1916) designated one of the specimens as the lectotype. This specimen is in the Academy of Natural Sciences at Philadelphia and is labeled

Tex.[as]/TYPE No. 2116 [red label]/Halictus bardus 665 Cr[esson][handwritten]/LECTOTYPE Halictus bardus Cresson des.[ignated by] Cresson, 1916 [handwritten, red label, labeled by McGinley, 1983].

The lectotype is an excellent condition except for missing the last two tarsomeres on both hind legs. The paralectotype is in the National Museum of Natural History, Smithsonian Institution.

DISTRIBUTION (Figure 302).—Lasioglossum bardum is presently known from 111 female specimens collected from seven counties in central Texas. Hurd (1979) indicated that this species is found from Texas to California; however, the records from New Mexico and Arizona were most likely based on specimens of L. morrilli, which are similar to L. bardum and were commonly misidentified by earlier workers. In central Texas, L. bardum and L. morrilli have contiguous distributions but as yet are not known to be sympatric.

DIAGNOSIS.—The combination of a short head (Figure 303, length/width ratio 0.75–0.92) and hyaline wing membranes will distinguish Lasioglossum bardum from other Lasioglossum species having an acarinarium on the first metasomal tergum I (Figure 307) except for L. jubatum and L. desertum. Lasioglossum jubatum, known from Mexico and southern Arizona, is easily recognized by its deep golden to pale ferrugineous mesoscutal pubescense (white in L. bardum). Lasioglossum desertum is very similar to L. bardum but has a much wider dorsal opening of the acarinarium (opening wider than lateral hair fringe in L. desertum, Figure 393; opening narrower than lateral hair fringe in L. bardum, Figure 307). Lasioglossum morrilli, which also occurs in Texas and is commonly confused with L. bardum, is highly distinctive with an elongate head (Figure 520, length/width ratio 0.86–0.96) and a highly polished, very sparsely punctate clypeus and supraclypeal area (granulate and moderately to densely punctate in L. bardum). The common and widespread species of the forbesii and trizonatum groups have not been collected from Texas. Furthermore, the pale yellowish brown wing membranes and relatively elongate heads of the latter species would distinguish them from L. bardum.

DESCRIPTION.—FEMALE: (1) Length 8.2–10.1 mm (x = 8.8, n = 20); (2) wing length 2.3–2.7 mm (x = 2.5, n = 20); (3) abdominal width 2.6–3.1 mm (x = 2.8, n = 20).

Structure: (4) Head moderately short (Figure 303; length/width ratio 0.75–0.92, x = 0.87, n = 20). (7) Supraclypeal area evenly rounded, (8) weakly protuberant. (9) Clypeus projecting approximately 0.73 its length below lower margin of eyes, (11) surface without median longitudinal sulcation. (14) Distance between lateral ocelli slightly exceeding distance between lateral ocellus and eye. (23) Flagellomere 1 shorter than 2 along dorsal surface. Labrum as in Figure 304; (27) distal keel broad as seen in frontal view, widest basally with conspicuous basal median groove; (28) distal lateral projections very well developed, strongly concave apically; (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 sharply edged. (35) Mesoscutal lip weakly bilobed, (36) moderately elevated. (40) Dorsal surface of propodeum about 0.70 the length of scutellum and about 1.2 times the length of metanotum, (41) slightly depressed centrally, (42) posterior margin broadly rounded; (43) propodeal triangle weakly defined, median portion slightly elevated, lateral rims weakly developed; (44) lateral carinae extending at most to midpoint of posterior surface. (45) Tibial spur as in Figure 22.

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

Sculpture: (47) Face shiny, (48) densely punctate below ocelli, punctures contiguous, becoming larger and less dense near antennae. (51) Supraclypeal area moderately granulate, (52) punctation nearly uniform, punctures 1–2 times their width apart. (53) Clypeus granulate basally, apical half polished (54) punctures well formed basally, separated by less than their width, becoming larger, somewhat obscure and less dense apically, apicolateral areas punctate. (56) Mesoscutum shiny; (57) punctation as in Figure 306, densely punctate laterally and anteriorly, punctures separated by their width or less, becoming more sparsely punctate centrally, punctures separated by 1–4 times their width. (58) Scutellar punctation nearly uniform, similar to that of central area of mesoscutum. (63) Dorsal surface of propodeum rugulose to ruguloso-striolate, striae obscurely reaching posterior margin (Figure 305); (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 and plumose. (77) Hind tibial hair color differentiated, most hairs white, dorsal hairs brown basally, becoming light-brown distally. (78) Anterior hairs of metasomal tergum I and (79) basal hair bands of terga II–IV white. (80) Acarinarium present (Figure 307), a large circular, glabrous area at base of tergum I, surrounded laterally and dorsolaterally by elongate fringe hairs, dorsal opening of acarinarium wide, opening subequal to or wider than width of lateral hair fringe as seen in dorsal view.

FLIGHT RECORDS (Figure 308).—Female L. bardum have been collected from late March to late September, with most records from May and June, with a peak in early June.

FLOWER RECORDS.—Females (103): Labiatae 47%; Onagraceae 31%. Total: 103 in 8 families, 10 genera as follows:

*Agalinis 6(6); Asclepias 2; Carduus 1; Hymenopappus 1; Lupinus 1; *Mimosa 2(2); *Monarda 48(29); *Oenothera 32(29); *Opuntia 3(1); Phacetia 7.

ADDITIONAL SPECIMENS EXAMINED.—110.

UNITED STATES. TEXAS: Gillespie Co.: Harper, 17 Apr 1953, L.D. Beamer (2; KU). Kerr Co.: Kerrville, 14 Jun 1907, F.C. Pratt (1; USNM), 17–19 Jun 1908, F.C. Pratt (4; USNM), 2 Apr 1959, W.R.M. Mason (1; CNC), 8 mi NW, 2 Jun 1975, C.D. Michener & party (39; KU); Kerrville State Park, 2 Jun 1975, C.D. Michener & party (1; KU). Menard Co.: Menard, 14 mi S, 2 Jun 1975, C.D. Michener & party (3; KU). McLennan Co.: Waco, 28 Aug 1906, F.C. Bishopp (2; USNM) (1; MCZ). Palo Pinto Co.: Mineral Wells, 6 May 1976, J.R. Powers (1; UCB). Travis Co.: Austin, 4 May 1900, A.L. Melander (1; WSU), 11 May 1969, B. Vogel (2; UColB), 28 Sep 1979, J. Neff (6; LACM), 2–7 May 1980, P.D. Hurd, Jr. (8; CU, USNM), 15 mi W, 25 Mar 1970, C.D. & M.H. Michener (1; KU), 22 mi NW, 31 May 1975, Michener & party (5; KU); Mansfield, 4 mi NE, 31 May 1975, Michener & party (20; KU). Victoria Co.: Victoria, 24 Apr 1907, F.C. Bishopp (1; USNM). Williamson Co.: Florence, 4 mi N, 30 May 1975, Michener & party (11; KU).