Lasioglossum acuminatum McGinley 1986

Lasioglossum acuminatum

TYPE MATERIAL.—The female holotype of L. acuminatum is deposited in the National Museum of Natural History, Smithsonian Institution. The specimen is missing the left hind leg beyond the coxa but is otherwise in excellent condition. It is labeled

NEW HAMPSHIRE: Sullivan Co.[unty], Lempster, 23-VI [June]-1976 FC&BJ Thompson/HOLOTYPE Lasioglossum acuminatum R.J. McGinley [red label].

Ninety-eight paratypes (77, 21) listed in the “Specimens Examined” section are designated.

ETYMOLOGY.—The specific epithet is derived from the Latin acumin (a point), alluding to the uniquely pointed, arrow-shaped acarinarium on the anterior surface of tergum I of the females.

DISTRIBUTION (Figure 406).—Lasioglossum acuminatum is primarily found in Canada and northern United States, from New Brunswick south to Pennsylvania and West Virginia, west through Michigan and Minnesota to central Alberta.

DIAGNOSIS.—The females of L. acuminatum can be distinguished from those of all other Lasioglossum species by the shape of the acarinarium on the anterior surface of tergum I, which is uniquely pointed and arrow-shaped (Figure 407). Other useful characters are the slightly elevated lateral rims on the posterior margin of the dorsal propodeal surface (Figure 414, characteristic of other forbesii group females) and the only moderately elongate head (Figure 410, length/width ratio x = 0.90, n = 20).

Lasioglossum acuminatum males have the yellow tarsi typical of other forbesii group males but have extremely elongate mandibles that nearly reach the opposing mandibular bases (Figure 411), very broad, moderately angulate genae that are slightly wider than the width of the compound eye as seen in lateral view and elongate hairs on sternum IV that are subequal in length to those on sternum III as seen in lateral view (Figure 418). Lasioglossum forbesii and L. paraforbesii males have shorter mandibles that at most reach only slightly beyond the opposing clypeal angles (Figures 426, 435) and shorter hairs on sternum IV than on sternum III (Figure 417). The gena of L. forbesii males is always narrower than the width of the eye as seen in lateral view, whereas that of L. paraforbesii is variable, in some cases subequal in width to the eye.

DESCRIPTION.—FEMALE: (1) Length 8.0–10.3 mm (x = 9.2, n = 20); (2) wing length 2.6–2.9 mm (x = 2.8, n = 20); (3) abdominal width 2.7–3.2 mm (x = 3.0, n = 20).

Structure: (4) Head moderately elongate (Figure 410, length/width ratio 0.85–1.0, x = 0.91, n = 20). (7) Supraclypeal area evenly rounded, (8) moderately protuberant. (9) Clypeus projecting approximately 0.91 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 subequal in length to 2 along dorsal surface. Labrum as in Figure 412; (27) distal keel moderately broad as seen in frontal view, slightly widest basally; (28) distal lateral projections somewhat moderately well developed, triangular; (29) fimbrial setae acutely pointed.

(32) Pronotal lateral angle narrowly 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 from pronotum. (40) Dorsal surface of propodeum about 0.79 the length of scutellum and about 1.5 times the length of metanotum, (41) slightly depressed centrally, (42) posterior margin broadly rounded; (43) propodeal triangle weakly defined laterally, evident medially as a V-shaped elevation with distinct lateral rims, fading towards mesonotum; (44) lateral carinae extending at most half the length of posterior surface. (45) Tibial spur as in Figure 15.

(46) Lateral edge of metasomal tergum II 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 weakly granulate, (51) punctation nearly uniform, punctures separated by their width laterally, slightly less dense centrally. (53) Clypeus granulate along basal edge; (54) punctures separated by their width or slightly less, apicolateral areas virtually impunctate. (56) Mesoscutum dull; (57) punctation as in Figure 415, punctures separated by their width or less laterally and anteriorly, less dense centrally, punctures 1–4 times their width apart. (58) Scutellum with conspicuous impunctate areas adjacent to median line. (63) Dorsal surface of propodeum (Figure 414) variable in sculpture, completely to incompletely ruguloso-striate; (64) surface alveolated. (65) Metasomal tergum I moderately shiny; (66) punctation fine, dense, punctures slightly less than their width apart.

Coloration: (71) Wing membrane pale yellowish brown.

Vestiture: (74) Pubescence of head yellowish white. (75) Pubescence of thorax yellowish white; (76) mesoscutal hairs moderately sparse and plumose. (77) Hind tibial hairs concolorous, yellowish brown. (75) Anterior hairs of metasomal tergum I pale yellowish brown, (77) basal hair bands of terga II–IV white. (80) Acarinarium present (Figure 407), a relatively small, arrowhead-shaped, glabrous area surrounded laterally by elongate fringe hairs, dorsal opening of acarinarium very narrow, width of opening approximately one-half the width of lateral fringe hairs as seen in dorsal view; unlike most species, each side of tergum I with conspicuous bald areas posteriad of acarinarial fringe hairs.

MALE: Similar to female except as follows: (1) length 7.2–8.8 mm (x = 8.2, n = 20); (2) wing length 2.1–2.5 mm (x = 2.3, n = 20); (3) abdominal width 1.8–2.3 mm (x = 2.1, n = 20). (4) Head as in Figure 411 (length/width ratio 0.91–1.0, x = 0.95, n = 20). (5) Gena slightly wider than eye, (6) strongly produced posteriorly. (10) Clypeal surface conspicuously flattened dorsally, shallowly depressed ventrally. Labrum as in Figure 413; (24) distal process developed as a moderately elongate, acute projection; (25) basal area depressed medially; (26) basal lateral depressions absent. (30) Mandible extremely elongate, reaching just short of opposing mandibular base. (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, contrasting with dark dorsum. (72) Tarsi yellow to yellowish orange.

Vestiture: Sternal vestiture as in Figure 418; (82) hairs on sternum IV erect, elongate medially, becoming shorter laterally (in lateral view, hairs of sternum IV subequal in length to those of sternum III, Figure 418; hairs of sternum IV relatively shorter in L. forbesii and L. paraforbesii);(83) sternum V without noticeable erect hairs or posterior hair lobes.

Terminalia: Sterna VII–VIII as in Figure 423; (85) sternum VIII with elongate, slender median process, broader apically than along stem. Genitalia as in Figures 419–422; (86) gonobase moderately elongate; (87) gonostylus broad, moderately elongate, narrowly rounded apically; (89) retrorse membranous lobe extremely slender; (90) volsella with very prominent lateral lobe.

FLIGHT RECORDS (Figure 424).—Females of L. acuminatum have been collected from April through October, with most records from June (50%). Males have been collected primarily in August and September, but one was taken in June (Barnstable County, Massachusetts) and six in late July.

FLOWER RECORDS.—Females (54): Ericaceae 46%; Rosaceae 17%; Compositae 11%. Males (49): Compositae 94%. Total: 103 in 13 families, 17 genera as follows:

Acer 1(1); Asclepias 2; Apocynum 1; *Brassica 1(1); Chamaedaphne 1; Clethra 1; *Lysimachia 1(1); Melilotus 1; Rhododendron 3; Prunus 1; Pyrus 2; *Rosa 3(3); *Rubus 6(2); *Salix 4(1); *Solidago 6(6), 46; Vaccinium 21; Viburnum 2.

SPECIMENS EXAMINED.—Paratypes (77, 21).

CANADA. NEW BRUNSWICK: Albert Co.: Albert Mines, W of, #567, taken on Vaccinium sp., 17-VI-77, P.G. Kevan, C. Holmes (1; INHS); Elgin, SW of, #581, taken on Vaccinium sp., 17-VI-77, P.G. Kevan, C. Holmes (1; INHS); Prosser Brook, S of, #426, taken on Vaccinium sp., 17-VI-77, P.G. Kevan, C. Holmes (1; INHS). Charlotte Co.: Honeydale, 3 mi SE, #22, 14-IV-74, Peter G. Kevan (1; INHS). Kings Co.: Hatfield Point, NE of, 17-VI-75, #138, P.G. Kevan, C. Holmes (1; INHS); Kingston, N of, #106, 119, 2-VI-76, Peter G. Kevan (2; INHS); Pigeon Hill, SW of Springfield, #53, 8-VI-1973, Peter G. Kevan (1; INHS); Springfield, SW of, #146, taken on Vaccinium sp., 16-VI-77, Peter G. Kevan, C. Holmes (1; INHS); West Scotch Settlement (N of Hatfield Point), #23, VI-9-1973, Peter G. Kevan (1; INHS). Queens Co.: Thorne (N of Belleisle Creek), #97, 9-VI-73, Peter G. Kevan (1; INHS). Westmorland Co.: Goshen, SW of, #248, 3-VI-76, Peter G. Kevan (1; INHS); Parkindale, SW of, #327, 329, 3-VI-76, Peter G. Kevan (2; INHS). County not specified: Kouchibouguac N.P., Code 5081K, 19-V-77, G.A.P. Gibson (1; CNC), Code 5172A, 30-V-77, G. Thompson (1, CNC), Code 6045M, 7-IX-77, S.J. Miller (1; CNC). NOVA SCOTIA. Hanks Co.: locality not specified, on Prunus, 12 Jun 1932, C.E. Atwood (1; USNM). ONTARIO. Kenora, 17 mi SE, 3 Aug 1967, J.R. Powers (1; UCB), 23 mi SE, sweeping flowers of Melilotus alba, 4 Aug 1967, J.R. Powers (1; UCB). QUEBEC. L’Ascension, VI-11-63, L.J. Jobin (1; CNC).

UNITED STATES. CONNECTICUT: [Litchfield Co.:] Colebrook, W.M. Wheeler (3, 1; MCZ), 6-13-26, W.M. Wheeler (1; MCZ). MAINE: Knox Co.: Glenmere, W.M. Wheeler (1; MCZ). [Lincoln Co.:] Waldoboro, #3247, on Acer saccharinum, 11 May 1905, J.H. Lovell (1; AMNH). MASSACHUSETTS: [Barnstable Co.:] Sagamore, J. Bequaert (1; MCZ). [Bristol Co.:] Horseneck Beach, Westport, 29 Jul 1930, Richard Dow (1; MCZ). [Middlesex Co.:] Lexington, 13 Aug, N. Banks (1; MCZ); Reading, 17-VI-33, (1; MCZ); Waltham, on Taraxacum offinale, 7-V-75, 8-V-57 (2), 14-V-57, R.A. Morse (4; CU). Norfolk Co.: Sharon, 25-VIII, C.W. Johnson (1; MCZ). [Suffolk Co.:] Milton, 20 Aug 1898 (second label reads “H. sp. near coriaceus, tarsi pale”) (1; MCZ). [Worcester Co.:] Winchendon, 1 Jul 1892, A.P. Morse (1; MCZ). County not specified: Petersham [?], VI-1932 (1; MCZ).

MICHIGAN: Cheboygan Co.: Duncan Bay, 27 Ju[n] 1958, 2 Jul 1958 [latter specimen only with R.A. Kepner collector label] (2; MSUEL); [Cheboygan Co.:] Douglas Lake, on Solidago, Ac. 23702, 17 Aug 1913, M.D. Ellis (1; AMNH); UMBS, Douglas Lake, summer 1960, Saul Frommer (1; UCR); locality not specified, VII-10-1959, R. & K. Dreisbach (1; MSUEL). Crawford Co.: locality not specified, VII-10-1959, R. & K. Dreisbach (1; MSUEL). Delta Co.: Escanaba, 28 Jun 1958, R.A. Scheibner (1; MSUEL). Dickinson Co.: locality not specified, 6-22-60, R. & K. Dreisbach (1; MSUEL). Emmet Co.: 5-27-60, R. & K. Dreisbach (1; MSUEL). Huron Co.: T18N, R11E, Sec. 21, VI-20-63, J. & L. Donahue (1; MSUEL). Mackinac Co.: locality not specified, 6-7-57, R. & K. Dreisbach (1; MSUEL). [Mecosta Co.:] Big Rapids, on wild rose, VI-5-1938, C.W. Sabrosky (3; MSUEL). Missaukee Co.: 6-30-57, R. & K. Dreisbach (1; MSUEL). Newaygo Co.: locality not specified, 5-13-56, R. & K. Dreisbach (1; MSUEL). Ogemaw Co.: Clear Lake, 3 Sep 1959, R.L. Fisher (1; MSUEL). Oscoda Co.: Luzerne, ex. window pane trap, 14 Jun 1966 (1), 28 Jun 1966 (7), L.F. Wilson (8; MSUEL). Presque Isle Co.: T33N, R11E, Sec. 33, 19 Jun 1968, N. & T. Baker (1; MSUEL). Wexford Co.: T24N, R9W, Sec. 22, pit trap in Jack pine plantation, 2–9 Aug 1965, J.H. Shaddy (1; MSUEL).

NEW HAMPSHIRE: Belknap Co.: locality not specified, on Aster macrophyllus, 23-VIII-60 (2), 26-VIII-60 (2), R.A. Morse (4; CU); [Belknap Co.:] Meredith Center, on Rubus sp., 23-VI-58, R.A. Morse (1; CU), on Apocynum adrosaemifolium, 4-VII-58, R.A. Morse (1; CU), on Brassica sp., 1-VII-59, R.A. Morse (1; CU), on Solidago sp., 3-VIII-57, R.A. Morse (1; CU); Meredith, on Aster lateriflorus, 28-VIII-60, R.A. Morse (1; CU), on Asclepias sp., 7-VIII-60, R.A. Morse (1; CU), on Solidago sp., 18-VIII-62 (1), 22-VIII-60 (2), 23-VIII-60 (1), R.A. Morse (4; CU). County not specified: #1864, C.F. Baker (1 USNM). NEW JERSEY: Burlington Co.: Lebanon St.[ate] Forest, VIII-19-58, Evans & Beneway (1; CU); Lebanon St.[ate] Forest, 4 mi N Chatsworth, 5 May 1968, G.C. Eickwort (1; CU). Ocean Co.: Lakehurst, 10 May 1969, G. & K. Eickwort (1; CU), 21-VIII-1974, R.C. Miller (1; CU); Long Beach Is[land], washed ashore beach alive, 5 May 1968, G. & K. Eickwort (1; CU). NEW YORK: Nassau Co.: Bethpage St.[ate] P[ar]k., 20 May 1975, G.C. Eickwort (1; CU). [Suffolk Co.:] Orient, 19 Jun 1954, Roy Latham, Roy Latham Collection (1; CU); Wading River, L.[ong] I.[sland], Stanford University [Collection], 22 Jun 1917 (1; UCB). Sullivan Co.: Yankee Lake, 20–26 Jul 1968, P. & R. Wygodzinsky (1; AMNH). County not specified: Tuxedo (Sta. Study Insects), VI-27-1928, C.H. Curran (1; AMNH); Tuxedo, n[ea]r., VIII-26-21 (2; AMNH).

PENNSYLVANIA: Huntingdon Co.: Huntingdon, 3 mi NE, 25 Jun 1973, T. Snyder (1; KU). [Monroe Co.:] Marshall Cr[eek]., VII-25-37, C.D. Michener (1; KU). Pike Co.: locality not specified, 11-VI-71, C. Jurica, M. Burgett (1; CU). County not specified: Lehigh Gap, VI-29-1901 (1; USNM).

Additional localities recorded (363 specimens: 250, 113).

CANADA. ALBERTA: Fawcett; Calgary. NEW BRUNSWICK: Albert Co.: Collier Mt. (south of Prosser Brook); Charlotte Co.: Moores Milles, St. Stephen, 5 mi W; Kings Co. NOVA SCOTIA: Hants Co.; Kings Co. ONTARIO: Bancroft; Bracebridge; Dorset; Dyer Bay; Garden River; Gravenhurst; Hornet Lake; Kenora (15 mi SE); Penage Lake; Vivian Forest. QUEBEC: Andreville (3 mi E Route 6).

UNITED STATES. CONNECTICUT: Tolland Co.: Mansfield Township (Gurleyville). MAINE: Cumberland Co.: Bailey Island; Hancock Co.: Acadia National Park; Lincoln Co.; Washington Co.: Jonesboro; York Co.: Kennebunk. MARYLAND: Prince George's Co.: Bowie. MASSACHUSETTS: Barnstable Co.: Nashawena Island (Elizabeth Islands); Dukes Co.: Plains (Martha's Vineyard); Hampden Co.: Ludlow; Middlesex Co.; Norfolk Co.: Needham, Wellesley; Suffolk Co.: Boston, Forest Hills; Worcester Co.: Holden. MICHIGAN: Allegan Co.: Allegan State Forest; Berrien Co.; Kalkaska Co.; Leelanau Co.: Glen Arbor; Manistee Co.: Manistee; Marquette Co.: Marquette; Midland Co.; Montmorency Co.: Atlanta; Presque Isle Co.: Ocqueoc Lake; Roscommon Co. MINNESOTA. Cass Co.: Pine River; Clearwater or Hubbard Co.: Itasca State Park. NEBRASKA: Bennett. NEW HAMPSHIRE: Sullivan Co.: Lempster. NEW JERSEY: Burlington Co.; Ocean Co.: Lakewood, Point Pleasant, Whiting, 3.8 mi W. NEW YORK: Albany Co.: Albany; Essex Co.; Franklin Co.: Saranac Lake; Orange Co.: Greenwood Lake; Suffolk Co. PENNSYLVANIA: counties not specified. West Virginia: Tucker Co.: near Davis. WISCONSIN: Douglas Co.: Solon Springs; Wood Co.: Griffith State Nursery.

Lasioglossum acuminatum là một loài Hymenoptera trong họ Halictidae. Loài này được McGinley mô tả khoa học năm 1986.