Lasioglossum (Evylaeus) cinctipes ( Provancher 1888 )

Gibbs, Jason, Packer, Laurence, Dumesh, Sheila & Danforth, Bryan N., 2013, Revision and reclassification of <i> Lasioglossum </ i> (<i> Evylaeus </ i>), <i> L. </ i> (<i> Hemihalictus </ i>) and <i> L. </ i> (<i> Sphecodogastra </ i>) in eastern North America (Hymenoptera: Apoidea: Halictidae), Zootaxa 3672 (1), pp. 1-116 : 68-74

Lasioglossum (Evylaeus) cinctipes ( Provancher 1888)

( Figs. 5L , 43A , 44A , 45A , 46A , 47 , 48 , 79A , 80A , 86A )

Halictus cinctipes Provancher 1888, p. 316 (♂)

Holotype. ♂ CANADA, Ontario, Ottawa [ ULQC]. Examined by JG 2011.

(Labels read “29/1125/ Halictus cinctipes Prov. [ancher] [handwritten]/ Lectotype 540 Halictus cinctipes Provancher Comeau 1744 [partially handwritten]/ Lectotype Halictus cinctipes Provancher 1125 Barron ’71 [partially handwritten; one line crossed out, illegible]”)

Halictus arcuatus Robertson 1893, p. 145 , ♀ (syn. Knerer & Atwood 1962)

Lectotype. ♀ USA, Illinois, Macoupin Co., Carlinville , 29.vi.1888 (C. A. Robertson) [ INHS 7993 ]. Designated by W. E. LaBerge in Webb 1980. Examined by JG 2011

Halictus crassus Vachal 1904, p. 477 (syn. Cockerell 1911, Brittain 1933)

Lectotype. ♀ USA, South Carolina [ MNHN]. Designated by Moure & Hurd (1987). Examined by JG 2012.

(Labels read “Carol S./Museum Paris Coll. O. Sichel 1867/ Holotype [handwritten on red label]/ crassus ♀ Vach [handwritten]/ Halictus crassus Vach. [handwritten on black-bordered label]”).

Halictus adelipus Vachal 1904, p. 479 (syn. Mitchell 1960)

Lectotype. ♂ USA, Tennessee [ MNHN]. Fixed by monotypy. Examined by JG 2011

(Labels read “Teness./Museum Paris Coll. O. Sichel 1867/ Holotype [handwritten on red label]/ adelipus ♂ Vach [handwritten]/ Halictus adelipus Vach. [handwritten on black-bordered label]”).

Halictus arcuatus var. parisus Lovell 1908, p. 36 (syn. Mitchell 1960)

Lectotype. ♀ USA, Maine, Lincoln Co., Waldoboro , 10.vii.1905 (J. H. Lovell); [ NMNH: 71571]. Designated by Covell (1972).

(Labels read “Type No. 71571 U.S. N.M. [handwritten on red label]/3698/Waldoboro, Me J.H. Lovell/ Rhus typhina July 10, 1905 [handwritten]/ Halictus arcuatus Robt var. parisus [illegible] ♀ [black bordered label]/ Halictus arcuatus var. parisus Lov. Lectotype [handwritten on red label]/ LECTOTYPE ♀ Halictus arcuatus var. parisus Lovell By C. V. Covell Jr. 1971 [partially handwritten on black-bordered label]/USNM ENT 00535148 [yellow label with barcode]”).

Halictus arcuatus gulosus Cockerell 1911, p. 661 (syn. Mitchell 1962)

Holotype. ♀ USA, Massachusetts, Barnstable Co., Woods Hole [ NMNH: 27991]

(Labels read “Woods Hole, Mass. July (Cockerell) [handwritten]/ Type No 27991 U.S. N.M. [number handwritten on red label]/ Halictus arcuatus gulosus Ckll TYPE [handwritten]/USNM ENT 00535165 [yellow label with barcode]”).

Halictus gulosus punctiferus Cockerell 1916a, p. 287 (syn. Timberlake in Michener 1951:catalogue)

Holotype. ♀ USA, Colorado, Boulder Co., Boulder, 14.iv (G. Mite) [ NMNH: 20293]

Evylaeus arcuatus (in Mitchell 1960 description, key ♀, ♂ misdet. of L. truncatum )

Evylaeus cinctipes (in Mitchell 1960: redescription, key ♂; Hurd 1979: catalogue; Moure & Hurd 1987: catalogue)

Halictus (Evylaeus) arcuatus (in Viereck 1916: catalogue)

Lasioglossum (Evylaeus) adelipus (in Michener 1951: catalogue)

Lasioglossum (Evylaeus) arcuatus arcuatus (in Michener 1951: catalogue)

Lasioglossum (Evylaeus) arcuatus parisus (in Michener 1951: catalogue)

Lasioglossum (Evylaeus) gulosus (in Michener 1951: catalogue)

Lasioglossum (Evylaeus) cinctipes (in Michener 1951: catalogue; Krombein 1967: catalogue)

Evylaeus (Evylaeus) cinctipes (in Pesenko 2007a: subgeneric classification)

Diagnosis. Female L. cinctipes can be recognised by the combination of head wide (L/W ratio = 0.83–0.93) ( Fig. 43A ); ocellocular area finely scabriculous; metapostnotum coarsely rugose ( Fig. 79A ); propodeal lateral carinae nearly reaching dorsal margin, diverging dorsally; inner metatibial spur serrate, with short, oblique teeth, length less than width of rachis ( Fig. 5L ); and T2 apical impressed area with numerous punctures ( Fig. 80A ). Lasioglossum cinctipes is superficially similar to L. truncatum , but the latter species differs in the following: ocellocular area smooth, distinctly punctate; propodeal lateral carinae subparallel; inner metatibial spur pectinate, with 4–5 narrow teeth, length of basal teeth slightly exceeding width of rachis ( Fig. 5Q ); and T2 apical impressed area impunctate ( Fig. 80B ).

Male L. cinctipes is unique among Eastern North American species in having the retrorse lobe absent ( Fig. 46A ). They can also be recognised by the combination of head wide (L/W ratio = 0.87–0.93) ( Fig. 44A ); clypeus not protruding much below suborbital line, distal margin yellow ( Fig. 44A ); F2 approximately equal in length to scape; T2 apical impressed area with numerous punctures ( Fig. 86A ); gonostylus short, without short hairs ( Fig. 45A ). Lasioglossum cinctipes is most similar to L. truncatum , but the latter species differs in the following: head longer (L/W ratio = 0.95–1.01) ( Fig. 44I ); clypeus protruding well below suborbital line; T2 apical impressed area with sparse punctures ( Fig. 86B ); retrorse lobe present ( Fig. 46I ); and gonostylus with long, plumose hairs ( Fig. 45I ).

Redescription. FEMALE. Length 6.2–8.3 mm. Head length 1.70–2.20 mm. Head width 1.99–2.38 mm. Wing length 4.9–6.4 mm. (n=8)

Colour. Head and mesosoma black. Antenna black, except ventral surface of flagellum brown. Tegula dark reddish brown. Legs dark brown, except medio- and distitarsi reddish brown. Wing membrane hyaline, faintly dusky. Pterostigma testaceous. Metasomal terga black-brown, apical margins pale brown-testaceous.

Structure. Head very wide (L/W ratio = 0.83–0.93). Clypeus 1/2 below suborbital line. Eyes convergent below (UOD:LOD = 1.04–1.11). Gena slightly wider than eye. Ocelli normal. Pronotum smoothly rounded, dorsolateral angle obtuse. Protibial spur with apical serrations as long as width of malus. Inner metatibial spur serrate, teeth 3– 6, basal teeth clearly shorter than width of rachis. Propodeal lateral carina, reaching dorsolateral slope, oblique carina indistinct from background sculpturing.

Surface sculpture. Supraclypeal area imbricate-weakly polished, punctures sparse (i=1–2.5d). Gena lineolate, postgena smoother. Mesoscutum polished, weakly imbricate anteromedially; punctures dense laterally (i≤d), wellspaced between parapsidal lines (i=1–2d). Mesepisternum rugose, weaker ventrally. Metapostnotum coarsely rugose. Propodeum imbricate-tessellate. Metasomal terga polished, apical impressed areas coriarious; punctures dense, distinct basally, finer apically.

Pubescence. Head and mesosoma with sparse plumose hairs. Metafemoral scopa with dense plumose hairs. Metasomal terga with relatively sparse, medially-interrupted apical fimbriae. T1 with sparse, erect plumose hairs. T2–T4 with dense basal bands of tomentum, sometimes medially (or entirely on T4) obscured by preceding segment. Metasomal sterna with plumose scopa.

MALE. Length 6.9–8.6 mm. Head length 1.68–1.99 mm. Head width 1.88–2.29 mm. Wing length 5.2–6.3 mm. (n=6)

Colour. Head and mesosoma black. Clypeus yellow on apical half, maculation size variable. Mandible brown basally, yellow apically. Labrum brown. Antenna black, except ventral surface of flagellum brown. Legs dark brown, except tarsi, anterior surface of protibia yellow-testaceous. Wing membrane hyaline. Pterostigma orangebrown. Metasomal terga dark brown, pale brown-testaceous apically.

Structure. Head wide (L/W ratio = 0.87–0.93). Clypeus ½ below suborbital line. Mandible short, reaching opposing clypeal angle. Flagellomeres, except F1 elongate, F2 longer than F1 and pedicel combined, subequal to scape. Eyes strongly convergent below (UOD:LOD = 1.37–1.44). Gena narrower than eye. Pronotum smoothly rounded. Propodeal lateral carina reaching dorsolateral slope, contiguous with strong oblique carina.

Surface sculpture. Supraclypeal area imbricate, with sparse punctures (i=1–2d). Gena and postgena lineolate. Mesoscutum polished, reticulate anterolaterally; punctures dense laterally (i≤d), clearly separated between parapsidal lines (i=1–1.5d). Mesepisternum rugulose. Metapostnotum carinate-rugose. Propodeum rugose. Metasomal terga polished, apical impressed areas faintly coriarious; punctures close throughout.

Pubescence. Head and mesosoma with sparse plumose hairs. Face below eye emargination with dense tomentum, sparser on clypeus. Propodeum largely bare, with scattered plumose hairs. Metasomal terga nearly bare, without apical fimbriae. T2–T4 with basolateral tomentum. Metasomal sterna nearly bare, with sparse, short, simple and plumose hairs (1–1.5 OD).

Terminalia . As shown in Figs. 45A , 46A . Gonostylus short, with short setae. Retrorse lobe absent.

Taxonomic notes. The type species of Evylaeus was originally designated by Robertson (1902b) to be Halictus arcuatus , which is now recognised as a junior subjective synonym of L. cinctipes ( Knerer & Atwood 1962; Mitchell 1962). Based on morphological study, L. cinctipes seems to belong to the laticeps species-group of the Palaearctic region. For example, both L. cinctipes and the laticeps group lack the retrorse lobe to the gonostylus (Packer 1997; Pesenko 2007a). Molecular phylogenetic study does not reveal a monophyletic L. ( Evylaeus ) or a close relationship of L. cinctipes with other members of the laticeps group ( Danforth et al. 2003; Gibbs et al. 2012a, b; Fig. 2 ). Intron regions of two nuclear genes have clear insertions in the laticeps group and other “carinate” Evylaeus , which are absent from L. cinctipes . Since L. cinctipes is the type species for L. ( Evylaeus ), understanding its phylogenetic placement is crucial for the subgeneric classification of the other “carinate Evylaeus ” species. Some Nearctic species, such as L. robustum and L. amicum , are believed to be close relatives of L. cinctipes based upon a combination of morphological characters and mitochondrial DNA sequences (JG, unpublished data).

Biology. Lasioglossum cinctipes is polylectic ( Moure & Hurd 1987) although the workers concentrate foraging on different species in different areas. In southern Ontario, they are almost entirely restricted to staghorn sumac ( Rhus typhina L.) ( Anacardiaceae ), whereas in Cape Breton Island, Nova Scotia, they are found extensively on wild rose ( Rosaceae ) ( Packer 2010). Lasioglossum cinctipes forms primitively eusocial colonies (Atwood 1933–as arcuatus ; Packer et al. 1989a, b) and foundresses are among the earliest halictine bees to become active in spring. Differentiation between queens and workers is sufficient to have allowed the two castes to be described as separate species ( Knerer & Atwood 1964) and they do not overlap in size. Unlike some halictine bees which display social plasticity, reverting to solitary behaviour at high latitudes, L. cinctipes may be obligately eusocial ( Packer et al. 1989b). Nests are built in soil with sessile brood cells not arranged in a cluster ( Packer et al. 1989b). Sphecodes minor Robertson (1898) has been recorded as cleptoparasite of L. cinctipes ( Knerer & Atwood 1967) .

DNA barcodes. Three specimens have been sequenced, including one sequence from GenBank (maximum intraspecific p-distance: 0.2%). The minimum interspecific p-distance between L. cinctipes and other eastern species is 13.5%. Thirteen fixed substitutions distinguish L. cinctipes from other species included herein: 42(T), 87(C), 99(A), 124(G), 171(C), 273(C), 280(A), 307(A), 370(A), 414(G), 444(C), 447(C), and 471(C) (see Table 2).

Range. Fig. 49 .

Material examined. 2761 (2244 females, 243 males). Deposited in ABS, ACNS, AMNH, ANSP, BBSL, CMNH, CNC, CSCA, CTMI, CUIC, EMEC, LACM, MCPM, MCZ, MSUC, PCYU, PMAE, PMNH , ROMent, UCMC, and UCRC.

CANADA. ALBERTA: Division 11: Edmonton; MANITOBA: Division 5: Ninette; Turtle Mt.; NEW BRUNSWICK: Charlotte Co.: St. Andrews; St. John Co.: St. John; York Co.: Fredericton; NOVA SCOTIA: Digby Co.: Digby; Smith’s Cove; Halifax Reg.: McNabs Is.; Sackville; Hants Co.; Kings Co.: East Torbrook; Kentville; Lunenburg Co.: Northwest Cove; Richmond Co.: Cape Breton, Irish Cove Rd., Wreck Cove; ONTARIO: Georgian Bay; Barrie Co.: Minesing; Brant Co.: Six Nations; Dufferin Co.: Orangeville; Haliburton Co.: Algonquin P.P., by Crossbar Lk.; Algonquin P.P., by Madawaska Lk.; Hastings Co.: Marmora; Tweed; Huron Co.: Kinburn; Kawartha Lakes Div.: Coboconk; Kenora Co.: Kenora; Kent Co.: Thamesville; Leeds and Grenville United Cos.: Chaffeys Lock, Queens U. Biol. Sta.; Lake Opinicon; Spencerville; Muskoka Dist.: Dorset; Dorset, Huntsville area; National Capital Reg.: Carp, 5 mi. W; Ottawa; Nipissing Dist.: North Bay; Ottawa Div.: Bell’s Corners; Parry Sound Dist.; Peel Reg.: Credit Forks; Prescott and Russell United Cos.: Gibbs Rd.; Renfrew Co.: Griffith, 7 mi. E; Toronto Reg.: Toronto; York U.; Waterloo Reg.: Elmira; PRINCE EDWARD ISLAND: Kings Co.: Mt. Hope; Queens Co.: Belle River; St. Andrews; QUEBEC: Mauricie Reg.: Shawinigan; Montérégie Reg.: Hemmingford; Mt. St. Bruno; Mt. St. Hilaire; Rougemont; St.-Paul-d’Abbotsford; Montreal Reg.: Montreal Is.; Outaouais Reg.: Aylmer; Aylmer, Queens Pk.; Chelsea; Gatineau Pk.; Hull; Ladysmith; SASKATCHEWAN: Division 11: Saskatoon.

USA. ARKANSAS: Conway Co.: Petit Jean S.P.; Logan Co.: Mt. Magazine, 10 mi SE Paris; Pulaski Co.: Little Rock; COLORADO: Boulder Co.: Boulder; Boulder, 1 mi. SW; Boulder, 2 mi. SW; Boulder, 6 mi. W; Douglas Co.: Deckers, 10 mi. NE; Sedalia, nr.; Jefferson Co.: El Dorado Springs; El Dorado Springs, 1 mi S; Montrose Co.: Gunnison R., Portal; CONNECTICUT: Fairfield Co.: Stamford; Hartford Co.: Hartford; Litchfield Co.: Colebrook; Westbury; New Haven Co.: New Haven; DISTRICT OF COLUMBIA: Washington; FLORIDA: Franklin Co.: Hickory Landing.; Gadsden Co.; Leon Co.: Tall Timbers Res. Sta., 3 mi W Iamonia; Liberty Co.: Torreya S.P.; GEORGIA: Richmond Co.: Augusta ; Fort Gordon; ILLINOIS: Cook Co.: Tinley Park; Macoupin Co.: Carlinville; Pope Co.: Lusk Creek; INDIANA: Tippecanoe Co.: LaFayette; IOWA: Plymouth/Woodbury Cos.: Sioux City; Story Co.: Ames; KANSAS: Cherokee Co.: Baxter Springs; Cheyenne Co.: St. Francis; Crawford Co.; Douglas Co.: Baldwin; Lawrence; Marshall Co.: Marysville; Pottawatomie Co.; Riley Co.; Wabaunsee Co.: Lake Wabaunsee; Manhattan; LOUISIANA: Natchitoches Par.: Natchitoches; MAINE: Lincoln Co.: Damariscotta, 3 mi. SE; Waldoboro; Penobscot Co.: Orono; Washington Co.; MARYLAND: Montgomery Co.: Glen Echo; Prince George’s Co.; MASSACHUSETTS: Barnstable Co.: Woods Hole; Bristol Co.: Westport, factory; Essex Co.: Andover; Hampden Co.: Holyoke; Middlesex Co.: Bedford; Medford; Plymouth Co.: Manomet Point; Suffolk Co.: Boston; MICHIGAN: Clare Co.: Harrison, 10 mi. N; Dickinson Co.: Channing; Sagola; Emmet Co.; Huron Co.: Port Hope; Iosco Co.; Kalamazoo Co.: Gull Lake Biol. Sta.; Kalkaska Co.; Keweenaw Co.: Ahmeek; Marquette Co.: Arnold; Witch Lk.; Ontonagon Co.: Bruce Crossing; Van Buren Co.: S. Haven, E of sandbar; Wexford Co.: Cadillac; MINNESOTA: Fillmore Co.: Fountain, 3 mi. N; Houston Co.: Money Creek, 2.5 mi. N; Oakland Co.: Pontiac Recreational Area; Olmstead Co.: Chatfield, 3 mi. E; Ramsey Co.: St. Paul; St. Louis Co.: Ely; Wabasha Co.: Lake City; MISSOURI: Howell Co.: Willow Springs; Jackson Co.: Atherton; Lincoln Co.: Cuivre S.P., 3 mi E of Troy; Shannon Co.: Round Spring State Pk.; NEBRASKA: Lancaster Co.: Lincoln; Malcolm; NEW HAMPSHIRE: Belknap Co.: Meredith; Meredith Ctr.; Carroll Co.: Chocorua; Charlotte Co.; Coos Co.: Lancaster; Shelburne; Grafton Co.: nr. Pemi. Riv., 0.68 mi NW Thornton; Strafford Co.: Durham; New Durham; NEW YORK: Albany Co.: Colonie; Rensselaerville; Rensselaerville, 2 mi S.; Rensselaerville, Huyck Preserve; Westerlo, 2 mi NW; Allegany Co.: Cuba; Broome Co.; Cattaraugus Co.: Otto; Cayuga Co. : Spring Lake; Chemung Co.; Delaware Co.: Gun House Hill, Hobart; Stamford; Essex Co.; Genesee Co.; Greene Co.; Jefferson Co.: Westcott Beach State Pk.; Lewis Co.; Monroe Co.: Rochester Junction; Nassau Co.: Bethpage State Pk.; Onondaga Co. : Syracuse; Otsego Co.: E. Worcester; Schuyler Co.: Hector Land Use Area, W of Reynoldsville; Sullivan Co.: Roscoe; Tompkins Co.: Ellis Hollow, 6 mi E of Ithaca; Ithaca, Buttermilk Falls State Pk.; Ithaca, Cornell U.; Ithaca, Coy Glen; Enfield, Teeter Rd.; Freeville; Ithaca; Ludlowville; Michigan Hollow; Six-Mile Creek, Ithaca; NORTH CAROLINA: Avery Co.: Grandfather Mt.; Bladen Co.; Brunswick Co.; Cumberland Co.: Manchester; Duplin Co.: Wallace; Harnett Co.: Lillington, 10 mi S; Haywood Co.: Cruso; McDowell Co.: Marion; Moore Co.: Aberdeen; Onalow Co.: Jacksonville; Pender Co.: Atkinson; Burgaw; Currie; Holly Shelter Game Range; Sampson Co.: Ivanhoe; Swain Co.: Bryson City; Forney Creek, Smokey Mt. N.P.; Wake Co.: Morrisville; Raleigh; Wilkes Co.: Moravian Falls; Scenic Hwy.; Yancey Co.: Black Mts.; OHIO: Franklin Co.: Columbus; Hacking Co.: Wayne Nat’l For., 4 mi N of Murray City; Ottawa Co.: Put-In-Bay; OKLAHOMA: Delaware Co.: Grove; Kingfisher Co.: Dover, 4 mi N; Latimer Co.: Wilburton; Major Co.: Meno, 5 mi NW; McCurtain Co.: Broken Bow; Idabel; Sherwood; Pawnee Co.: Pawhuska; Pittsburg Co.: Quinton; PENNSYLVANIA: Allegheny Co.: Harmarville; Pittsburgh; Sewickley; Lehigh Co.: Lehigh Gap River; Susquehanna Co.: Mud Pond, S. Gibson; Tioga Co. : Mansfield; Westmoreland Co.: Jeannette; SOUTH CAROLINA: Aiken Co.: Aiken; Chesterfield Co.; SOUTH DAKOTA: Bon Homme Co.: Springfield; Custer Co.: Custer S.P.; Grant Co.: Big Stone City; Hughes Co.: Pierre; Lawrence Co.: Whitewood; TEXAS: Bastrop Co.: Sayers; Lee Co.: Fedor; Menard Co.: Menard, 10.3 mi N; Uvalde Co.: Uvalde, 3 mi NW; VERMONT: Addison Co.; Bennington Co.: Manchester; Orleans Co.: E. Charleston; Windham Co.: Putney; VIRGINIA: Falls Church; Arlington Co.: Glencarlyn; Carroll Co.: Laurel Fork; Fairfax Co.: Barcroft; Dunn Loring; Vienna; WEST VIRGINIA: Greenbrier Co.: Alvon; Pendleton Co.: Spruce Knob; WISCONSIN: Burnett Co.: Yellow River; Douglas Co.: St. Croix Dam; Grant Co.: Boscobel; Wyalusing; Jackson Co.; Milwaukee Co.: Milwaukee; Monroe Co.; Pierce Co.: Maiden Rock; Prescott; Polk Co.: Farmington Twp.; Vernon Co.: Genoa; Walworth Co.: Army Lake, nr. East Troy; Washington Co.: Cedar Lake; Wood Co.

SUBGENUS SPHECODOGASTRA ASHMEAD 1899

Sphecodogastra Ashmead 1899 a: 92 .

Type species: Sphecodes texana Cresson 1872 , by original designation

Halictus (Calchalictus) Warncke 1975: 99 . [new synonymy] 1

Type species: Apis calceata Scopoli 1763 , by original designation.

Halictus (Inhalictus) Warncke 1975: 96 . [new synonymy] 1

Type species: Hylaeus interruptus Panzer 1798 , by original designation.

Minutulaeus Pesenko 2007a: 11 . [new synonymy] 2

Type species: Hylaeus minutulus Schenck 1853 , by original designation.

Nodicornevylaeus Pesenko 2007a: 11 . [new synonymy] 2

Type species: Halictus nodicornis Morawitz 1889 , by original designation and monotypy.

Monilevylaeus Pesenko 2007a: 13 . [new synonymy] 2

Type species: Halictus immunitus Vachal 1895 , by original designation and monotypy.

Tricinctevylaeus Pesenko 2007a: 14 . [new synonymy] 2

Type species: Halictus tricinctus Schenck 1874 , by original designation.

Fratevylaeus Pesenko 2007a: 14. [new synonymy] 1

Type species: Halictus fratellus Pérez 1903 , by original designation.

Malachevylaeus Pesenko 2007a: 15 . [new synonymy] 1

Type species: Melitta malachura Kirby 1802 , by original designation.

Pauxevylaeus Pesenko 2007a: 11 . [new synonymy] 1

Type species: Hylaeus pauxillus Schenck 1853 , by original designation.

1. Synonymy supported by molecular phylogenetic result.

2. No members of this group have been included in molecular phylogenetic studies. The synonymy is based on morphological studies of halictid bees and traditional placement in the “carinate Evylaeus ” ( Ebmer 1995, 2002; Michener 2007; Pesenko 2007a).

Lasioglossum (Sphecodogastra) has previously been restricted to a small number of Onagraceae specialists occurring in North America ( Moure & Hurd 1987; McGinley 2003). The eight species of Onagraceae specialists likely form a monophyletic clade ( Danforth et al. 2003; Gibbs et al. 2012b), which renders the “carinate Evylaeus ” paraphyletic. Three species of this type have been identified east of the Mississippi River: L. oenotherae , L. texanum , and L. lusorium . All species in L. ( Sphecodogastra ) s. s. are crepuscular, matinal, or nocturnal floral specialists with solitary or communal nests ( Kerfoot 1967a; Knerer & MacKay 1969; McGinley 2003). In all L. ( Sphecodogastra ) s. s., the metafemoral scopa is modified for the collection of pollen held together by viscine threads in the host plants ( Fig. 74B ; McGinley 2003, his figures 2, 3, 25, 26). In L. texanum and L. noctivaga Linsley and MacSwain (1962) , the ocelli are greatly enlarged to facilitate activity in low-light conditions ( Kerfoot 1967a). In some classifications, L. oenotherae and L. lusorium have been treated as L. ( Evylaeus ) ( Linsley & MacSwain 1962; Moure & Hurd 1987). Bohart and Youssef (1976) included L. texanum in L. ( Evylaeus ), but this violates the principle of priority (ICZN 1999).

Lasioglossum (Sphecodogastra) as applied herein includes many polylectic, diurnal species. Lasioglossum (Sphecodogastra) s. l. includes solitary species, species with annual eusocial (e. g. Packer & Owen 1989) or semisocial colonies ( Packer et al. 1989b), and delayed eusociality ( Packer 1993).

Subgeneric diagnosis

The subgenus Lasioglossum (Sphecodogastra) is complicated to diagnose even on a local scale, in part due to the highly modified forms of the Onagraceae specialists. In America north of Mexico, L. ( Sphecodogastra ) females can be distinguished from other Lasioglossum subgenera by the following combination of characters. Head and mesosoma with black integument, lacking metallic reflections; vein 1rs-m (second submarginal cross vein) weak ( Fig. 1A ); inner metatibial spur variable, often pectinate, with teeth longer than width of rachis ( Fig. 5 M-Q); propodeum with strong lateral and oblique carina, separating lateral and posterior propodeal surfaces ( Fig. 79 B-F); or if carina weak ( Fig. 83B ) then femoral scopa of hind leg modified to rake-like row of hairs ( Fig. 74B ).

Lasioglossum (Sphecodogastra) males can be distinguished from other Lasioglossum by the following combination of characters. Head and mesosoma with black integument, lacking metallic reflections; metasomal sterna nearly bare with only sparse, short (<1 OD) pubescence ( Fig. 85A ) or, if sternal hairs longer and denser, then S6 with raised longitudinal area ( Fig. 85B ); clypeus gently rounded, not flat; size usually moderate (5.9–8.8 mm). Lasioglossum (Hemihalictus) males have moderately long pubescence on the metasomal sterna (1–2.5 OD). Lasioglossum (Leuchalictus) males are coarsely sculptured with distinctive hair patterns on S6 (either an inverted V-shape in L. leucozonium or medial hair tufts in L. zonulum ). Most Lasioglossum s. s. males have a distinctly flat clypeus, except L. fuscipenne , which is easily distinguished by its distinct sternal hairs ( McGinley 1986).

Figures

FIGURE 1. Forewings of female Lasioglossum with arrows indicating weak distal veins. (A) Individual with three submarginal cells. (B) Individual with two submarginal cells. Basal vein (b), pterostigma (pt). Numbers indicate submarginal cells. Modified from Gibbs (2010a).

FIGURE 2. Inferred phylogeny of the Hemihalictus series of Lasioglossum based on 1 mitochondrial and 3 nuclear genes partitioned by genome and codon position and analysed using a mixed evolutionary model and Bayesian methods (modified from Gibbs et al. 2012b). Species included in our revision are denoted with black branches in the tree. Colour-coded bars represent subgenera (see legend). From left to right each column represents a different proposed classification: Michener (2007), Ebmer (2002) and our revised cladistic classification. Since Michener and Ebmer do not discuss each species or taxon included in our phylogeny some subgenera are left blank. The columns do not necessarily represent the opinions of those authors, but are based on our understanding of standard usage, which largely follows their proposed classifications.

FIGURE 5. Drawings of inner metatibial spurs of female Lasioglossum subgenera Hemihalictus (A-K), Evylaeus (L), and Sphecodogastra (M-Q). (A) L. birkmanni. (B) L. fedorense. (C) L. foxii. (D) L. inconditum. (E) L. lustrans. (F) L. macoupinense. (G) L. nelumbonis. (H) L. pectinatum. (I) L. pectorale. (J) L. sopinci. (K) L. swenki. (L) L. cinctipes. (M) L. boreale. (N) L. comagenense. (O) L. quebecense. (P) L. seillean. (Q) L. truncatum. See McGinley (2003) figures 61, 62, and 65 for images of inner metatibial spurs of L. lusorium, L. oenotherae, and L. texanum.

FIGURE 43. Faces of female Lasioglossum subgenera Evylaeus (A) and Sphecodogastra (B-I) in frontal view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 44. Faces of male Lasioglossum subgenus Evylaeus (A) and Sphecodogastra (B-I) in frontal view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 45. Genital capsules of male Lasioglossum subgenera Evylaeus (A) and Sphecodogastra (B-I) in dorsal view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 46. Genital capsules of male Lasioglossum subgenus Evylaeus (A) and Sphecodogastra (B-I) in ventral view. (A) L. cinctipes. (B) L. boreale. (C) L. comagenense. (D) L. lusorium. (E) L. oenotherae. (F) L. quebecense. (G) L. seillean. (H) L. texanum (I) L. truncatum. Scale bar = 1 mm.

FIGURE 47. Lateral habitus of female Lasioglossum (Evylaeus) cinctipes (Provancher). Scale bar = 1 mm.

FIGURE 48. Lateral habitus of male Lasioglossum (Evylaeus) cinctipes (Provancher). Scale bar = 1 mm.

FIGURE 49. Distribution map of Lasioglossum (Evylaeus) cinctipes (Provancher). Heat map indicates predicted suitable range based on maximum entropy niche-modelling. Black circles indicate actual geo-referenced specimen records.

FIGURE 74. Scopa of hind leg. (A) L. boreale—unmodified scopa. (B) L. oenotherae—modified scopa for Onagraceae pollen collection.

FIGURE 79. Propodeum and metapostnotum of female Lasioglossum (Evylaeus) and L. (Sphecodogastra). (A) L. cinctipes showing coarse, rugose sculpture. (B) L. truncatum showing coarse, rugose sculpture. (C) L. boreale showing fine sculpture and weak propodeal carinae. (D) L. comagenense showing fine sculpture and distinct propodeal carinae. (E) L. quebecense showing fine sculpture and distinct propodeal carinae. (F) L. seillean showing fine sculpture and distinct propodeal carinae.

FIGURE 80. Metasomal terga of female Lasioglossum. (A) L. cinctipes showing finely punctate apical impressed areas. (B) L. truncatum showing impunctate apical impressed areas.

FIGURE 83. Propodeum and metapostnotum of female Lasioglossum (Sphecodogastra) in the Onagraceae specialist lusorium species-group. (A) L. oenotherae showing coarse sculpture and strong carinae. (B) L. lusorium showing fine sculpture and weak carinae.

FIGURE 85. Metasomal sterna of male Lasioglossum (Spheocodagastra) with arrows indicating pubescence and S6 medial area. (A) L. boreale showing short, sparse hairs and normal S6. (B) L. oenotherae showing long, dense hairs and concave S6.

FIGURE 86. Metasomal terga of male Lasioglossum (Sphecodogastra). (A) L. cinctipes showing numerous punctures on apical impressed areas. (B) L. trunctatum showing few punctures on apical impressed areas.