Lasioglossum (Hemihalictus) macoupinense ( Robertson 1895 )

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 : 35-39

Lasioglossum (Hemihalictus) macoupinense ( Robertson 1895)

( Figs. 4F , 5F , 6F , 7F , 8F , 24 , 25 )

Halictus 4-maculatus Robertson 1890, p. 316 (♂) (preocc. Schenck 1853)

Lectotype ♀ USA, Connecticut, Waterbury , 9.vii.1879 (W.H. Patton). [ ANSP: 4256]. Designated by Cresson (1928). Examined by JG 2012.

(Labels read “July 9 ’79 [handwritten] W—bury, Ct. W. H. Patton/ Lectotype 4256 [red label]/ Halictus 4-maculatus Rob. [handwritten on red-bordered label]/Collection of the Academy of Natural Sciences of Philadelphia (ANSP)”)

Halictus quadrimaculatus Robertson in Cockerell 1895, p. 65 (justified emendation)

Halictus macoupinensis Robertson 1895, p. 117 (new name for Halictus 4-maculatus Robertson)

Halictus divergens Lovell 1905b, p. 299 ♀ [new synonymy]

Lectotype. ♀ USA, Maine, Lincoln Co., Waldoboro, 24.vi. [ NMNH: 71567] (Metasoma missing). Designated by Covell (1972).

(Labels read “Type No. 71567 U.S. N.M. [handwritten]/1894/Waldoboro Maine /cultivated Blackberry June 24 [handwritten]/ Halictus divergens ♀ Type/ Halictus divergens Lov. Holotype [handwritten]”)

Evylaeus divergens (in Mitchell 1960 ♀; Knerer & Atwood 1964 ♂; Hurd 1979: catalogue; Moure & Hurd 1987: catalogue) Lasioglossum (Evylaeus) divergens (in Michener 1951: catalogue; Krombein 1967: catalogue)

Diagnosis. Both sexes of L. macoupinense can be recognised by the combination of head long (L/W ratio = 1.02– 1.09) ( Figs. 4F , 6F ), supraclypeal punctation sparse (i=1–2.5d), pronotum smoothly rounded dorsolaterally, and mesepisternum distinctly punctate (as in Fig. 76B ). Lasioglossum macoupinense can be easily distinguished from most species, except L. birkmanni . Both sexes of L. birkmanni have head shorter (L/W ratio = 0.94–0.99) ( Figs. 4A , 6A ). Female L. birkmanni have denser punctation on supraclypeal area (i≤d). Male L. birkmanni have shorter setae on the gonostylus ( Fig. 7A ) than do L. macoupinense ( Fig. 7F ). The female of L. pectinatum is superficially similar to L. macoupinense in some characteristics but can be easily separated by the pronotum and inner metatibial spur (compare Figs. 5F and 5H ).

Redescription. FEMALE. Length 5.2–6.6 mm. Head length 1.42–1.65 mm. Head width 1.35–1.65 mm. Wing length 4.1–4.8 mm. (n=5)

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

Structure. Head long (L/W ratio = 1.02–1.06). Clypeus ¾ below suborbital line. Eyes convergent below (UOD:LOD = 1.22–1.31). Gena narrower than eye. Ocelli normal. Pronotum smoothly rounded dorsolaterally. Protibial spur with apical serrations shorter than width of malus. Inner metatibial spur pectinate, teeth 3–4, basal teeth much longer than width of rachis. Propodeal lateral carina not reaching dorsal margin, oblique carina low, obscure.

Surface sculpture. Supraclypeal area imbricate, punctures sparse (i=1–2.5d). Gena and postgena lineolate. Mesoscutum polished; punctures dense laterally (i≤d), distinctly separated between parapsidal lines (i=1–2d). Mesepisternum smooth, polished, distinctly punctate (i=1–2d). Metapostnotum carinate-rugose basally, apical margin weakly imbricate. Propodeum imbricate-tessellate, with fine vertical carinulae extending to dorsolateral slope. Metasomal terga polished, apical impressed areas weakly coriarious; punctures dense, obscure posteromedially.

Pubescence. Head and mesosoma with sparse plumose hairs. Metafemoral scopa of dense plumose hairs. Propodeal lateral surface with mixed simple and plumose hairs. Metasomal terga without apical fimbriae. T1 with sparse, erect plumose hairs. T2–T3 with basolateral patches of dense tomentum. Metasomal sterna with plumose scopa.

MALE. Length 4.8–5.1 mm. Head length 1.35–1.51 mm. Head width 1.24–1.41 mm. Wing length 4.0– 4.1 mm. (n=3)

Colour. Head and mesosoma black. Clypeus apical half yellow. Mandible brown basally, yellow apically. Labrum yellow. Antenna black, except ventral surface of flagellum brown. Legs dark brown, except tarsi, bases and apices of pro- and mesotibiae yellow, protibia largely yellow-testaceous. Wing membrane hyaline. Pterostigma brown. Metasomal terga dark brown.

Structure. Head long (L/W ratio = 1.06–1.09). Mandible short, reaching opposing clypeal angle. Flagellomeres, except F1 moderately elongate, F2 shorter than F1 and pedicel combined, much shorter than scape. Eyes convergent below (UOD:LOD = 1.46–1.50). Gena narrower than eye. Pronotum smoothly rounded. Propodeal lateral carina nearly reaching dorsolateral slope.

Surface sculpture. Supraclypeal area imbricate, with sparse, shallow punctures (i=1–2d). Gena and postgena lineolate. Mesoscutum polished; punctures dense laterally (i≤d), clearly separated between parapsidal lines (i=1– 2.5d). Mesepisternum polished, distinctly punctate. Metapostnotum carinate-rugose, apical margin imbricate. Propodeum weakly rugulose laterally, posterior surface weakly imbricate. Metasomal terga polished; punctures deep, close basally; T2–T6 apical impressed areas impunctate.

Pubescence. Head and mesosoma with sparse plumose hairs. Paraocular area below eye emargination with relatively sparse tomentum. Propodeum largely bare, with scattered plumose hairs. Metasomal terga nearly bare, apical fimbriae extremely sparse. Metasomal sterna with sparse, plumose hairs (1.5–2 OD).

Terminalia . As shown in Figs. 7F , 8F . Gonostylus small, with short setae. Retrorse lobe long, narrow, attenuated apically.

Taxonomic notes. The type series of Halictus 4-maculatus Robertson is comprised of specimens collected in Connecticut, Tennessee, and Illinois ( Robertson 1890). The specimen from Connecticut collected by W. H. Patton was designated as the lectotype by Cresson (1928). Examined by JG 2012. The choice of lectotype is incongruent with the etymology of the name. The epithet macoupinense , applied to replace the preoccupied H. 4-maculatus, is a reference to Macoupin County, Illinois, where Charles Robertson collected extensively in Carlinville. Other members of the type series of H. 4-maculatus were collected at this location so the choice of a Connecticut specimen was odd. Unfortunately, the type series is also composed of two distinct species. The lectotype belongs to the species most commonly referred to in the literature as L. divergens , based on the elongate head, which is incongruent with long standing usage of the name L. macoupinense . Lasioglossum macoupinense has usually been applied to the brown-legged form of L. birkmanni (see above), which differs by the relatively short head. Robertson’s (1890) original description states that H. 4-maculatus has “head broad...clypeus hardly produced”. This description seems more congruent with typical usage of the species name (see Mitchell 1960), rather than the long-faced species designated by Cresson.

Lovell (1908) considered L. divergens to be a junior synonym of L. macoupinense based on a perceived gradient of characteristics between the two species. This synonymy has not been widely accepted but due to the lectotype type designation of Cresson (1928) should now be put into use. Although L. macoupinense and L. birkmanni are morphologically very similar, they can be distinguished based on the characteristics listed in the diagnosis. DNA barcodes also support the recognition of both species (see below).

Mitchell (1960) described Evylaeus divergenoides and suggested it might be the male of L. divergens (as E. divergens ). The holotype specimen of Evylaeus divergenoides was recently examined by one of us (JG) and it was discovered to be a male of L. versans , a relatively dark metallic species of L. (Dialictus) ( Gibbs 2011). The correct male of L. divergens , now L. macoupinense , was first recognised and described by Knerer and Atwood (1964).

Biology. This species is polylectic ( Moure & Hurd 1987). There are no published records of its nesting biology or sociality, but it is believed to be a solitary ground-nester based on the biology of related species ( Danforth et al. 2003; Gibbs et al. 2012b; see L. birkmanni below).

DNA barcodes. Sixteen specimens sequenced (maximum intraspecific p-distance: 0.3%). A minimum pdistance of 3.9% separates DNA barcodes of L. macoupinense and its close relative L. birkmanni . Lasioglossum macoupinense differs from L. birkmanni by 21 fixed substitutions: 15(C), 30(T), 66(C), 129(C), 132(C), 216(A), 219(T), 270(T), 276(T), 315(A), 339(T), 354(C), 363(T), 378(T), 420(C), 423(T), 460(C), 552(T), 558(T), 639(C), and 642(T) (see Table 2). Three fixed substitutions distinguish L. macoupinense from all other species included herein: positions 66(C), 420(C), and 460(C).

Range. Fig. 26 .

Material examined. 693 (619 females, 74 males). Deposited in ACNS, AMNH, ANSP, CMNH, CAS, CNC, CUIC, EMEC, IRCW, MCPM, MCZ, MSUC, PCYU, PMAE, PMNH , ROMent, and UCRC.

CANADA. ALBERTA: Division 1: Medicine Hat; Division 2: Lethbridge; BRITISH COLUMBIA: Fraser Valley Reg. Dist.: MacGillivray Creek Game Res., nr. Chilliwack; Mission City; North Okanagan Reg. Dist.: Vernon; Okanagan-Similkameen Reg. Dist.: Oliver, 5 mi. NW; MANITOBA: Division 2: Lorette; Division 7: Aweme; Carberry; Shilo, 5 mi. SW; NEW BRUNSWICK: Kent Co.: Kouchibouguac N.P.; York Co.; Sunbury Co.: Fredericton; NOVA SCOTIA: Colchester Co.: Truro; Digby Co.; Hants Co.; Kings Co.: Lakeville; Morristown; ONTARIO: Dundas Co.: Morrisburg; Durham Reg.: Kendal; Essex Co.: Point Pelee; Grey Co.: Priceville; Haliburton Co.: Algonquin P.P., by Crossbar Lk.; Algonquin P.P., by Madawaska Lk.; Hastings Co.: Chatterton; Madoc; Marmora; Trenton; Kent Co.: Bothwell; Rondeau Pk.; Thamesville; Lambton Co.: Florence; Leeds Co.: Brown’s Bay; Muskoka Dist.: Dorset; National Capital Reg.: Ottawa; Niagara Co.; Norfolk Co.: Manestar Tract; Normandale; Peel Reg.: New Glasgow; Rainy River Dist.: Fort Frances; Rainy River; Toronto Reg. Dist.: Toronto; Simcoe Co.: Orillia; Sudbury Dist.: Penage Lake; PRINCE EDWARD ISLAND: Kings Co.: Albion Cross; Mt. Hope; Peakes; Saint Georges; St. Patrick Rd.; West St. Peters; Woodville Mills; Queens Co.: Belle River; Dromore; Fredericton; Glenroy; Mt. Vernon; St. Andrews; Winsloe; York; QUEBEC: Abitibi-Témiscamingue Reg.: Laniel; Strawberry Isle, Kipawa Lk.; Montcalm Co.: Mont Pleasant P.P.; Montérégie Reg.: Dunham; St. Hyacinthe; Montreal Reg.: Montreal; Montreal Is.; Outaouais Reg.: Aylmer, Queens Pk.; Chelsea; Bernard; Gatineau Pk., Harrington Lk.; Kazabazua; Luskville; SASKATCHEWAN: Northumberland Co.: Port Hope; Division 7: South Lake.

USA. COLORADO: El Paso Co: Foster Ranch; CONNECTICUT: Litchfield Co.: Colebrook; New Haven Co.; Waterbury; GEORGIA: Rabun Co.: Rabun Bald; IOWA: Lee Co.; MAINE: Knox Co.: Glenmere; Lincoln Co.: Waldoboro; Oxford Co.: Norway; MASSACHUSETTS: Dukes Co.: Cuttyhunk Is.; Martha’s Vineyard; Essex Co.: Gloucester; Franklin Co.: Heath; Hampshire Co.: Granby; Middlesex Co.: Lexington; Reading; MICHIGAN: Alger Co.; Barry Co.: Yankee Springs Game Area; Clare Co.; Clinton Co.: Bath; Rose Lake Wildlife Res. Area Delta Co. : Brampton; Dickinson Co.: Channing; Sagola; Emmet Co.; Ingham Co.; East Lansing; Iron Co. ; Jackson Co.: MacCready Res.; Kalamazoo Co.: Gull Lake Biol. Sta.; Mackinac Co.; Manistee Co.: Kaleva; Midland Co.; Oakland Co.: Pontiac; Van Buren Co.: Keeler; Wayne Co.; MINNESOTA: Hennepin Co.: Minnetonka, U of Minnesota arboretum; Ramsey Co.: St. Paul, McAlister College; Roseau Co.: Roseau; MISSOURI: St. Louis Co.: Tyson Res. Sta., nr. Eureka; NEW HAMPSHIRE: Belknap Co.: Meredith; Meredith Ctr.; Cheshire Co.: Jaffrey; Coos Co.: Lancaster; Mt. Washington, Alpine Garden; Grafton Co.; NEW YORK: Albany Co.: Huyck Preserve, nr. Rensselaerville; Westerlo, 2 mi NW; Allegany Co.: Cuba; Cayuga Co. : Fair Haven Beach; Clinton Co.: Pern; Cortland Co.: Labrador Lake; Essex Co.: Keene Valley; Hamilton Co.: 8 th Lake, 3 mi. E inlet; Limekiln Lake, 3 mi. S inlet; Lewis Co.; Monroe Co.; Niagara Co.; Orleans Co.; Oswego Co.: Selkirk Shores S.P.; Saratoga Co.; Seneca Co. : Montezuma Nat. Wildlife Ref.; Van Etten, 2 mi. W; Tioga Co. ; Tompkins Co.: Caroline, Speed Hill; Enfield, Teeter Rd.; Ithaca; Ithaca, Cornell U.; Ithaca, Monkey Run; Ithaca, Six-Mile Creek; Ithaca, Van Natta’s Dam; Ludlowville; Mud Creek; Warren Co.: Loon Lake; Washington Co.; NORTH CAROLINA: Henderson Co.: Whiteside Mt.; Macon Co.: Highlands; McDowell Co.: Blue Ridge Pkwy.; OHIO: Franklin Co.: Columbus; Macon Co.: Franklin; Portage Co.: Breakneck Creek floodplain, 4.5 mi. E Kent; PENNSYLVANIA: Allegheny Co.; Erie Co.: LeBoeuf; McKean; SOUTH DAKOTA: Pennington Co.: Fs Rd. 358.18; VERMONT: Bennington Co.; Lamoille Co.: Hyde Park; Windsor Co.: Woodstock; VIRGINIA: Falls Church; WISCONSIN: Grant Co.: Wyalusing; Milwaukee Co.: Milwaukee; Pierce Co.: Prescott; St. Croix Co.: North Hudson; Vernon Co.: Genoa.

Figures

FIGURE 4. Faces of female Lasioglossum subgenus Hemihalictus in frontal view. (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. Scale bar = 1 mm.

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 6. Faces of male Lasioglossum subgenus Hemihalictus in frontal view. (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. Scale bar = 1 mm.

FIGURE 7. Genital capsule of male Lasioglossum subgenus Hemihalictus in dorsal view. (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. Scale bar = 1 mm.

FIGURE 8. Genital capsule of male Lasioglossum subgenus Hemihalictus in ventral view. (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. Scale bar = 1 mm.

FIGURE 24. Lateral habitus of female Lasioglossum (Hemihalictus) macoupinense (Robertson). Scale bar = 1 mm.

FIGURE 25. Lateral habitus of male Lasioglossum (Hemihalictus) macoupinense (Robertson). Scale bar = 1 mm.

FIGURE 26. Distribution map of Lasioglossum (Hemihalictus) macoupinense (Robertson). Heat map indicates predicted suitable range based on maximum entropy niche-modelling. Black circles indicate actual geo-referenced specimen records.

FIGURE 76. Mesepisternum of female Lasioglossum. (A) L. inconditum showing weak, rugulose sculpture. (B) L. pectinatum showing punctation. (C) L. pectorale showing coarse, rugose sculpture throughout. (D) L. comagenense showing weak, rugulose sculpture. (E) L. lusorium showing appressed pubescense. (F) L. truncatum showing rugose sculpture becoming rugulose anterior to mesocoxa.