Lasioglossum xyriotropis McGinley 1986

Lasioglossum xyriotropis

TYPE MATERIAL.—The holotype female of Lasioglossum xyriotropis is in the National Museum of Natural History, Smithsonian Institution. It is labeled

Pablillo, N.L. [Nuevo Leon] 23.VI [June]. 1975 MEX.[ico]/ J.E. Gillaspy Collector/HOLOTYPE Lasioglossum xyriotropis R.J. McGinley [red label].

The left pair of wings are folded under the specimen and pierced by the insect pin but otherwise the holotype is in excellent condition. Six female paratypes, listed in the “Specimens Examined” section, are herein designated; five are in the Snow Museum, University of Kansas, and one in the Cornell University Collection.

ETYMOLOGY.—The Greek words xyrion (small razor) plus tropis (keel) allude to the complete and very sharply edged pronotal lateral carina, characteristic of this species.

DISTRIBUTION (Figure 504).—Lasioglossum xyriotropis is presently known only from three Mexican states: Morelos, Nuevo Leon, and Tlaxcala.

DIAGNOSIS.—Very characteristic of L. xyriotropis is the clypeus that is conspicuously and almost entirely granulate (only the extreme apicolateral edges are polished). Also diagnostic is the following character combination: head moderately short; pronotal lateral carina conspicuously complete and sharply edged (Figure 732); membrane of forewing mostly hyaline, marginal cell and apex infuscated; mesoscutum nearly entirely granuloso-punctate, punctures slightly less dense on central posterior surface, where they are nearly contiguous but distinctly separated. Like L. manitouellum, to which it is very similar, L. xyriotropis lacks an acarinarium and has a noticeably shiny, striolate-rugulose dorsal propodeal surface. Lasioglossum manitouellum, unlike L. xyriotropis, has an incomplete pronotal lateral carina, a slightly shorter head (Figure 505), and a completely granuloso-punctate mesoscutum (punctures not distinctly separated posteriorly).

Lasioglossum xyriotropis is also similar to L. heterorhinum, with which it shares the complete pronotal lateral carina. The following characters of L. heterorhinum will differentiate these two species: apical half of clypeus polished; head conspicuously short (Figure 458; compare with Figure 505); forewing membrane not infuscated.

DESCRIPTION.—FEMALE: (1) Length 7.9–9.6 mm (x = 8.8, n = 7); (2) wing length 2.4–2.7 mm (x = 2.5, n = 7); (3) abdominal width 2.62.9 mm (x = 2.7 mm).

Structure: (4) Head moderately short (slightly longer than that of L. manitouellum, Figure 505; length/width ratio 0.92–0.96, x = 0.95, n = 7). (7) Supraclypeal area evenly rounded, (8) moderately protuberant. (9) Clypeus projecting approximately 0.74 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 slightly shorter than 2 along dorsal surface. (27) Labral distal keel broad in frontal view, somewhat spoon-shaped; (29) distal lateral projections virtually absent, evident as obscure lateral swellings; (29) fimbrial setae acutely pointed.

(32) Pronotal lateral angle obtuse; (33, 34) pronotal lateral ridge conspicuously complete, sharply edged (Figure 732). (35) Mesoscutal lip weakly bilobed, (36) moderately elevated from pronotum. (40) Dorsal surface of propodeum about 0.80 the length of scutellum and about 1.3 times the length of metanotum, (41) depressed centrally, (42) posterior margin broadly rounded; (43) propodeal triangle weakly defined, median V-shaped elevation and lateral rims inconspicuous; (44) lateral carinae extending over jthree-quarters the length of posterior propodeal surface, nearly reaching posterior edge of dorsal surface.

(46) Lateral edge of metasomal tergum II sinuate.

Sculpture: (47) Face shiny, (48) densely punctate below ocelli, punctures contiguous, only slightly less dense near antennae. (51) Supra—clypeal area clypeal area granulate throughout; (52) punctures separated by less than their width laterally, separated by 1–2 times their width centrally. (53) Clypeus nearly granulate throughout, polished only on extreme apicolateral edges; (54) punctures well formed basally, nearly contiguous, becoming larger and obscurely formed on apical half, separated by 1–2 times width. (56) Mesoscutum moderately shiny; (57) punctation similar to that in Figure 510, mostly granuloso-punctate, punctures nearly contiguous but distinctly separated on central posterior surface. (58) Scutellar punctures separated by their width centrally, nearly contiguous near edges (impunctate areas absent). (63) Dorsal surface of propodeum irregularly striate laterally, becoming ruguloso-striolate medially, striae and rugulae reaching posterior margin (similar to that in Figure 509); (64) surface obscurely alveolated (unlike most species except L. manitouellum, the propodeal dorsal surface is noticeably shiny). (65) Metasomal tergum I moderately dull; (66) punctation extremely fine, punctures virtually contiguous over most of doral surface.

Coloration: (71) Wing membrane nearly hyaline, lightly pigmented throughout with infuscated marginal cell and apex.

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

FLIGHT RECORDS.—One L. xyriotropis female was collected in April, the other six were taken in June.

MITE ASSOCIATES.—Although L. xyriotropis lacks an acarinarium, the one female from Morelos had numerous hypopodes clustered on the anterior surface of tergum I.

SPECIMENS EXAMINED.—7.

MEXICO, MORELOS: Cuernavaca, 4 mi NW, 12 Apr 1959, 7500 ft, H.E. Evans (1; CU). NUEVO LEON: Pablillo, 23 Jun 1975, J.E. Gillaspy (1 holotype; USNM). TLAXCALA: Apizaco, 8 mi W, 18 Jun 1961, 8200 ft, Univ. Kansas Mex. Exped. (5; KU).