Lasioglossum (Dialictus) albipenne (Robertson)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 57-61

Lasioglossum (Dialictus) albipenne (Robertson)

( Figures 66A–E , 67A–H )

Halictus palustris Robertson, 1890: 317 . ♀ ♂. (Preocc. Morawitz, 1876)

Holotype. ♀ USA, [New Hampshire] Jefferson ♀ [ ANSP: 4252] [new synonymy]. Examined.

Halictus albipennis Robertson, 1890: 317 . ♀ ♂.

Holotype. ♀ USA, Illinois, [Carlinville] (C. Robertson); [ ANSP: 4251]. Examined.

Halictus nymphaearus Robertson, 1895: 117 (new name for H. palustris ).

Halictus paludicola Dalla Torre, 1896: 75 (new name for H. palustris ).

Halictus nubilis Lovell, 1905a: 40 . ♀.

Lectotype. ♀ USA, Maine, Waldoboro , 2.viii. (J.H. Lovell); [ NMNH: 71570] by C. V. Covell, Jr. Examined. Halictus (Chloralictus) lactineus Sandhouse, 1924: 34 . ♂. [new synonymy]

Holotype. ♀ USA, Colorado, Boulder , 4.viii.1908 (S.A. Rohwer); [ NMNH: 26435]. Examined.

Halictus (Chloralictus) basilicus Sandhouse, 1924: 36 . ♂. [new synonymy]

Holotype. ♂ USA, Connecticut, Colebrook, 1–7.ix., (W.M. Wheeler); [ NMNH:26439]. Examined.

Taxonomy. Robertson, 1902: Chloralictus albipennis , p. 249 (key); Viereck, 1916: Halictus (Chloralictus) albipennis , p. 707 (key); Michener, 1951: Lasioglossum (Chloralictus) albipenne , p. 1111, L. (C.) basilicum , p. 1112, L. (C.) lactineum , p. 1114 (catalogue); Mitchell, 1960: Dialictus albipennis ♂, p. 378, D. basilicus ♂, 383 (redescription); Knerer and Atwood, 1966a: Dialictus basilicus ♀, p. 881 (description); Krombein, 1967: Lasioglossum (Dialictus) albipenne , p. 462, L. (D.) basilicum , p. 462 (catalogue); Hurd, 1979: Dialictus albipennis , p. 1963, D. basilicus , p. 1964, D. lactineus , p. 1967 (catalogue); Moure & Hurd, 1987: Dialictus albipennis , p. 88, D. basilicus , p. 92, D. lactineus , p. 109 (catalogue).

Diagnosis. Females of L. albipenne can be recognised by the diagnostic combination of a bluish green head and mesosoma, white wings with very pale yellow pterostigma and venation, coarse mesoscutal punctures which are sparse medially (i=1–3d), coarsely reticulate-rugose mesepisternum, strongly carinate propodeum, large and dense T1 acarinarial fan, and metasomal terga brown with dense tomentum and distinct punctures throughout. Females of this species are most similar to L. cressonii , L. disparile (Cresson) , and L. oceanicum . Female L. cressonii are golden green on the head and mesosoma, have relatively dense mesoscutal punctures (i=1–1.5d) and faintly dusky wings. Female L. disparile have a distinct glabrate band on the declivitous surface of T1 separating the acarinarial fan from a dorsal pubescent band. Female L. oceanicum have a complete transverse carina separating the dorsal and posterior surfaces and distinctly reflexed hypostomal carina.

Males of L. albipenne are similar to females but may be further distinguished by their elongate heads (length/width ratio = 0.99–1.08) with abundant white hairs obscuring the face, hyaline wings, relative short flagellomeres (length/width ratio = 1.21–1.31) which are bright yellow ventrally, and punctate-reticulate mesepisternum. Males of this species are most similar to L. pruinosum and L. oceanicum . Male L. pruinosum have a yellow apical maculation on the clypeus. Male L. oceanicum have a distinctly punctate tegula.

Redescription. FEMALE. Length 5.19–6.10 mm; head length 1.66–1.85 mm; head width 1.61–1.82 mm; forewing length 4.51–5.00 mm.

Colouration. Head and mesosoma bluish green to green. Clypeus with apical half blackish brown, basal half and supraclypeal area brassy. Antenna dark brown, flagellum with ventral surface reddish to yelloworange. Tegula amber with inner margin dark brown. Wing membrane hyaline, venation and pterostigma pale yellow. Legs brown, protibial base amber, tarsi infused with reddish amber. Metasomal terga dark brown or blackish brown, apical impressed areas translucent amber.

Pubescence. Dull white. Relatively dense. Head and mesosoma with moderately dense woolly hairs (1–2 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Paraocular area without tomentum. Gena without tomentum. Propodeum with plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasoma with dense, fine setae. T1 acarinarial fan large, complete, without dorsal opening, meeting erect transverse hair band at dorsal margin of declivitous surface. T2 basolaterally and T3–T4 extensively obscured by appressed tomentum. T2 apicolateral and T3–T4 apical margins with weak fringes.

Surface sculpture. Face imbricate, punctation strong. Clypeus polished, basal margin imbricate, punctation moderately sparse (i=1–2d). Supraclypeal and lower paraocular areas with punctation dense (i≤d). Antennocular area punctation moderately dense (i=0.5–1.5d). Upper paraocular area and frons reticulate-punctate. Ocellocular area punctate (i≤d). Gena and postgena striate. Mesoscutum weakly imbricate, submedial portion polished, punctation coarse, moderately sparse between parapsidal lines (i=1–3d), closer laterad of parapsidal line (i≤d), contiguous on anterolateral portion. Mesoscutellum imbricate, submedial area polished, coarsely punctate. Axilla punctate. Metanotum rugulose. Preëpisternum rugose. Hypoepimeral area ruguloso-reticulate. Mesepisternum strongly reticulate. Metepisternum with dorsal half rugoso-striate, ventral half imbricate. Metapostnotum coarsely rugoso-striate. Propodeum with dorsolateral slope and lateral and posterior surfaces rugulose. Metasoma polished, weakly coriarious on T1 declivitous surface and apical impressed areas, punctation close throughout (i=1–2d).

Structure. Head moderately elongate (length/width ratio = 1.00–1.03). Eyes convergent below (UOD/ LOD ratio = 1.19–1.26). Clypeus 2/3 below suborbital tangent, apicolateral margins convergent. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending <2 OD below median ocellus. Gena narrower than eye. Inner metatibial spur pectinate with 3–4 teeth. Metapostnotum moderately elongate (MMR ratio = 1.23–1.36), posterior margin sharply angled onto posterior surface. Propodeum with oblique carina moderately strong, lateral carina moderately strong, reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.61– 6.85 mm; head length 1.54–1.85 mm; head width 1.43–1.72 mm; forewing length 3.97–4.58 mm.

Colouration. Head and mesosoma pale green. Flagellum with ventral surface yellow. Tibial bases and apices, and tarsi yellow.

Pubescence. Face below level of eye emargination entirely obscured by dense, white appressed tomentum. S2–S3 apical halves and S4 lateral portion with moderately dense subappressed hairs (1.5 OD).

Surface sculpture. Mesepisternum coarsely reticulate, becoming more distinctly punctate below. Dorsal surface of propodeum coarsely rugose. Lateral and posterior portions of propodeum coarsely rugose. Marginal zones impunctate.

Structure. Head elongate (length/width ratio = 0.99–1.08). Eyes strongly convergent below (UOD/LOD ratio = 1.43–1.49). Clypeus 2/3–3/4 below suborbital tangent, apicolateral margins convergent. Antennal sockets distant (IAD/OAD> 1.1). Frontal line carinate, ending <2 OD below median ocellus. Pedicel longer than F1. F2 length 1.3–1.4X F1. F2–F10 short (length/width ratio = 1.21–1.31). Metapostnotum moderately elongate (MMR ratio = 1.20–1.29), posterior margin sharply angled onto posterior surface. Propodeum with oblique carina strong but obscure among sculpture, lateral carina strong.

Terminalia . S7 with median lobe narrowly clavate, sides subparallel, apex rounded ( Fig. 67F ). S8 with apicomedial margin weakly convex ( Fig. 67F ). Genitalia as in Fig. 67D–E . Gonobase with ventral arms narrowly separated. Gonostylus small, dorsal setae elongate. Retrorse lobes narrow, weakly attenuated apically.

Range. Nova Scotia west to British Columbia, south to North Carolina, Colorado and Oregon ( Fig. 65 ).

Additional material examined. CANADA: ALBERTA: 1♂ Waterton Lakes N.P., Cardston Ent., 2.vii– 3.viii.2000; [ BDUC] ; BRITISH COLUMBIA: 1♀ Midway, Hwy 3, N49.01384 W118.79568, 585 m ,

8.vi.2007 (Gibbs & Sheffield); MANITOBA: 1♀ 1♂ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank, N49°40´51´´ W099°33´15´´ , 23.viii.2005 (A.M. Patenaude); 1♀ YellowQuill Mxd., Grass Prairie Preserve, near Treesbank, N49°40´51´´ W099°33´16´´, 30.viii.2005 (A.M. Patenaude); NEW BRUNSWICK: 3♀ Kent Co., St. Ignace , N46.707 W071.054 , 32. vii.2005 (M. Gravel); NOVA SCOTIA: 1♀ Kings Co., Kentville (Ag. Can.), N45.0694 W064.4835 , 7.vi.1999 (S. Rigby); 5♀ Kings Co., Kentville, N45.0628 W064.4881 , 31.v.2002 (C. Sheffield); [ PCYU]; ONTARIO: 4♀ Cooksville , 20.vi.1964 (G. Knerer); 1♂ Toronto, 18.viii.1962 (G. Knerer ); 1♂ Toronto D.M ., 11.ix.1963 (G. Knerer ); 2♀ Toronto D.M ., 13.vi.1963 (G. Knerer ); 1♀ Toronto D.M ., 16.vi.1963 (G. Knerer ); 1♀ Toronto D.M ., 9.ix.1963 (G. Knerer ); 1♀ Toronto N .. , 27.vi.1963 (G. Knerer); [ ROM]; PRINCE EDWARD ISLAND: 1♀ Queens Co ., 6.vii.2006 ( V. MacPhail ); [ PCYU]; SASKATCHEWAN: 2♀ Assiniboia , 25.vi.1955 (J. R. Vockeroth ); [ CNC]; USA: COLORADO: 1♀ Boulder Co., N39°57´50.4´´ W105°15´4.1´´ (Kearns & Oliveras) ; IOWA: 1♀ Clay Co., Iowa Chicago & Eastern RR, 410, 0.8 km E Everly N43°09´37´´ W095°18´31´´ , 11.vi.2003 (C. Hemsley ); MAINE: 1♀ Hancock Co., N44.3608 W068.23 , 20.vi. (H.W. Ikerd); MINNESOTA: 1♀ 3 mi E, 2 mi S Felton, Felton Prairie , N47°02´59´´ W096°26´59.8´´ , 21.vii.2006 ( R.L. Andres); 1♀ 4 mi E, 1 mi S Glyndon, Bluestead Prairie , N46°51´21.8´´ W096°28´18.4´´ , 2.vi.2006 ( R.L. Andres ); NEW JERSEY: 1♀ Hunterdon Co., N40.56 W074.96 , 21.vii.2004 (H. Gaines ); WEST VIRGINIA: 1♀ Hampshire Co., N39.2425 W078.6137 , 11.vii.2002 (S.W. Droege ); [ PCYU]; WISCONSIN: 1♂ Marinette Co., N45.2441 W87.81875 , 28.vii.2005 (J. Watson); [ ARC] .

Floral records. APIACEAE : Zizia aurea , APOCYNACEAE : Apocynum androsaemifolium , ASTER- ACEAE: Antennaria neglecta , Anthemis cotula , Arnoglossum muehlenbergii , Conyza canadensis , Erigeron annuus , E. philadelphicus , E. strigosus , Eupatorium perfoliatum , Eurybia furcata , E. macrophyllum , Helianthus strumosus , Krigia biflora , Leucanthemum vulgare , Ratibida pinnata , Rudbeckia hirta , R. subtomentosa , Solidago canadensis , S. juncea , S. missouriensis , Symphyotrichum lanceolatum var. lanceolatum , Taraxacum , ASCLEPIADACEAE : Asclepias verticillata , BRASSICACEAE : Barbarea , Rorippa teres CUCURBITA- CEAE: Cucurbita , FABACEAE : Dalea candida var. oligophyllus , D. purpurea , Melilotus officinalis , GROS- SULARIACEAE: Ribes , LAMIACEAE : Salvia , LILIACEAE : Allium canadense , A. cernum , Maianthemum racemosum , ONAGRACEAE : Oenothera fruticosa , OXALIDACEAE : Oxalis corniculata , O. violacea , ROSACEAE : Potentilla , Rubus , RUBIACEAE : Houstonia purpurea calycosa , SANTALACEAE : Comandra umbellata , SAXIFRAGACEAE : Mitella diphylla .

Comments. Common. The lectotype of Halictus palustris Robertson clearly belongs to L. albipenne and does not match the species traditionally referred to as L. nymphaearum (Robertson) (replacement name for H. palustris ) (see comments for L. oceanicum below).

According to Knerer and Atwood (1966) females of L. basilicum lack “the salient rim” of the propodeum which is characteristic of L. albipenne . The strength of the oblique propodeal carinae is variable but forms a gradient in long series and is never completely absent.

Figures

FIGURE 65. Distribution of Lasioglossum admirandum (dark grey) and L. albipenne (light grey).

FIGURE 66. Lasioglossum albipenne (Robertson). Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) mesoscutum; (E) metapostnotum. Scale bars, A–C = 1 mm.

FIGURE 67. Lasioglossum albipenne (Robertson). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) mesepisternum; (E) ventral view of genital capsule; (F) dorsal view of genital capsule; (G) S7, S8; (H) metapostnotum. Scale bars, A–C = 1 mm, G = 0.5 mm.