Lasioglossum parkeri McGinley 1986

Lasioglossum parkeri

TYPE MATERIAL.—The female holotype of L. parkeri is deposited in the University of California at Davis and is labeled

10 mi. east Zitacuaro Mich.[oacan] MEX.[ico] III [Mar] 26 1962/F.D. Parker L.A. Stange Collectors/HOLOTYPE Lasioglossum parkeri R.J. McGinley [red label].

When received, the abdomen was loosely attached to the thorax and is now contained in a micro-vial pinned with the specimen (gluing the abdomen may have obscured details of the diagnostic acarinarium). The specimen is otherwise in excellent condition.

ETYMOLOGY.—This species is named after F.D. Parker (Bee Biology and Systematics Laboratory and Utah State University), who along with L.A. Stange (Florida State Collection of Arthropods, Gainesville) collected the unique female holotype.

DISTRIBUTION (Figure 569).—This species is presently known only from the type-locality: 10 miles east of Zitacuaro, Michoacan (on the border of the state of Mexico).

DIAGNOSIS.—The female of this species can be recognized by its distinctive acarinarium (at the base of abdominal tergum I), which is a concave, circular, glabrous surface completely surrounded by erect fringe hairs (Figure 582). The only other New World Lasioglossum with an acarinarium completely surrounded by fringe hairs is L. coriaceum, a species from the eastern United States. The fringe hairs of L. coriaceum are adpressed, not erect (Figure 72). Lasioglossum parkeri appears to be related to the Mexican L. pallicorne as evidenced by the unusual dorsal propodeal surface that is surrounded by conspicuously elevated lateral rims (as in Figure 574). Like L. pallicorne, the propodeal dorsal surface is smooth (conspicuously alveolated) over its posterior half, the head is short (similar to Figure 570), and the mesoscutal punctation is dense but not quite granuloso-punctate (as in Figure 575). Lasioglossum pallicorne is easily differentiated from L. parkeri by its bilaterally depressed, heart-shaped acarinarium (Figure 578).

DESCRIPTION.—FEMALE: (1) Length 8.8 mm (n = 1); (2) wing length 2.5 mm; (3) abdominal width 2.7 mm.

Structure: (4) Head short (similar to that of L. pallicorne, Figure 570); length/width ratio 0.83. (7) Supraclypeal area evenly rounded, (8) moderately protuberant. (9) Clypeus projecting approximately 0.67 of its length below lower margin of eyes; (11) surface without median longitudinal sulcation. (14) Distance between lateral ocelli slightly shorter than distance between lateral ocellus and eye. (23) Flagellomere 1 subequal to 2 in length along dorsal surface. Labrum similar to that of L. pallicorne (Figure 572) but (27) distal keel not so broad, basal median groove not so conspicuous, (28) distal lateral projections small, triangular; (29) fimbrial setae acutely pointed.

(32) Pronotal lateral angle broadly obtuse; (33) pronotal lateral ridge appearing complete, only slightly notched by oblique lateral sulcus but not distinctly interrupted; (34) lower portion of lateral ridge sharply edged. (35) Mesoscutal lip weakly bilobed, (36) moderately elevated from pronotum. (40) Dorsal surface of propodeum very elongate, about 0.92 the length of scutellum and about 1.6 times the length of metanotum, (41) depressed centrally, (42) posterior margin rounded; (43) propodeal triangle well defined medially by a sharply edged V-shaped elevation with conspicuous lateral rims, becoming faint towards metanotum; (44) lateral carinae extending at most one-third the length of posterior surface. (45) Tibial spur similar to that of L. pallicorne (Figure 45).

(46) Lateral edge of metasomal tergum II only faintly sinuate, virtually straight.

Sculpture: (47) Face shiny, (48) densely and uniformly punctate between ocelli and antennae, punctures contiguous. (51) Supraclypeal area moderately granulate; (52) punctation extremely sparse with few, scattered punctures. (53) Clypeus moderately granulate basally, apical two-thirds moderately polished; (54) punctures obscure basally, separated by their width over apical half. (56) Mesoscutum shiny; (57) punctation similar to that in Figure 575, punctures dense, nearly contiguous laterally and anteriorly, punctures becoming slightly less dense centrally, punctures separated by their width or slightly less. (58) Scutellum largely impunctate centrally. (63) Dorsal surface of propodeum similar to that of L. pallicorne (Figure 574), ruguloso-striolate on basal half, smooth on posterior half; (64) surface extensively alveolated. (65) Metasomal tergum I moderately shiny; (66) punctation fine, extremely dense, punctures nearly contiguous; surface nearly glabrous posteriad to acarinarial hair fringes (Figure 582).

Coloration: (71) Wing membrane pale yellowish brown.

Vestiture: (74) Pubescence of head pale yellowish brown. (75) Pubescence of thorax yellowish brown; (76) mesoscutal hairs moderately dense and plumose. (77) Hind tibial hair color differentiated, most hairs on dorsal surface brown, hairs yellowish brown on ventral and lateral surfaces. (78) Anterior hairs of metasomal tergum I pale yellowish brown, (79) basal hair bands of terga II–IV yellowish white. (80) Acarinarium present (Figure 582), a concave, circular, glabrous area, completely surrounded by erect fringe hairs; area posteriad of acarinarium conspicuously hairless.

MITE ASSOCIATES.—The one female available for study had her acarinarium partially filled with histiostomatid hypopodes.

SPECIMENS EXAMINED.—One holotype female, Zitacuaro, 10 mi E, Michoacan, Mexico, 26 Mar 1962, F.D. Parker and L.A. Stange (UCD).