Lasioglossum (Hemihalictus) foxii ( 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 : 27-29

Lasioglossum (Hemihalictus) foxii ( Robertson 1895)

( Figs. 4C , 5C , 6C , 7C , 8C , 18 , 19 , 75C , 82B )

Halictus gracilis Robertson 1890, p. 316 ♂ (preocc. Morawitz 1865)

Lectotype. USA, Illinois, Macoupin Co., Carlinville (C. A. Robertson) [ ANSP: 4255]. Designated by Cresson (1928).

Examined by JG 2012.

(Labels read “Robertson S. Illinois / Lectotype 4255 [numbers handwritten]/ Halictus gracilis Rob. [handwritten]”). Halictus foxii Robertson 1895, p. 117 . New name for Halictus gracilis Robertson.

Halictus gracillimus Dalla Torre 1896, p. 63 . New name for Halictus gracilis Robertson

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

Halictus (Evylaeus) foxi [sic](in Viereck 1916: catalogue)

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

Diagnosis. Both sexes of L. foxii can be recognised by the combination of head long (L/W ratio = 1.03–1.10) ( Figs. 4C , 6C ); mesepisternum finely rugulose (as in Fig. 76A ); and metapostnotal rugae not reaching the smoothly rounded posterior margin of dorsal surface ( Fig. 82B ). The most similar species in eastern North America is L. inconditum , which has metapostnotal rugae reaching posterior margin in both sexes ( Fig. 82C ).

Redescription. FEMALE. Length 5.4–6.1 mm. Head length 1.57–1.74 mm. Head width 1.52–1.65 mm. Wing length 4.3–4.9 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 = 1.03–1.05). Clypeus ¾ below suborbital line. Eyes convergent below (UOD:LOD = 1.08–1.15). Gena narrower than eye. Ocelli normal. Pronotum smoothly rounded. Protibial spur with apical serrations as long as width of malus. Inner metatibial spur pectinate, teeth 3–4, basal teeth much longer than width of rachis. Metapostnotum posterior margin smoothly rounded. Propodeal lateral carina not reaching dorsal margin, oblique carina absent.

Surface sculpture. Supraclypeal area polished medially, punctures sparse (i=1–2d). Gena weakly imbricatelineolate, postgena imbricate. Mesoscutum imbricate; punctures dense laterally (i≤d), distinctly separated between parapsidal lines (i=1–1.5d). Mesepisternum finely rugulose, imbricate ventrally. Metapostnotum carinate-rugose basally, apical margin imbricate. Propodeum imbricate-tessellate. Metasomal terga polished; punctures dense, obscure posteromedially.

Pubescence. Head and mesosoma with sparse plumose hairs. Metafemoral scopa with dense plumose hairs. Metasomal terga with apical fimbriae very sparse. T1 with sparse, erect plumose hairs. Metasomal sterna with plumose scopa.

MALE. Length 4.4–6.0 mm. Head length 1.40–1.56 mm. Head width 1.27–1.45 mm. Wing length 3.5–4.4 mm. (n=5)

Colour. Head and mesosoma black. Clypeus yellow distally. Mandible brown basally, yellow apically. Labrum yellow. Antenna black, except ventral surface of flagellum reddish brown. Legs dark brown, except tarsi, bases and apices of tibiae testaceous-pale brown. Wing membrane hyaline. Pterostigma orange-brown. Metasomal terga dark brown.

Structure. Head long (L/W ratio = 1.05–1.10). Mandible short, reaching opposing clypeal angle. Flagellomeres, except F1 elongate, F2 longer than F1 and pedicel combined, subequal to scape. Eyes convergent below (UOD:LOD = 1.48–1.57). Gena narrower than eye. Pronotum smoothly rounded. Propodeal lateral carina reaching less than half distance to dorsolateral slope.

Surface sculpture. Supraclypeal area polished medially, punctures relatively dense (i=1–1.5d). Gena lineolate, postgena imbricate. Mesoscutum weakly imbricate, polished posteromedially; punctures moderately dense laterally (i=1–2d), clearly separated between parapsidal lines (i=1–2.5d). Mesepisternum weakly rugulose, imbricate ventrally. Metapostnotum carinate-rugose, apical margin imbricate. Propodeum weakly rugulose laterally, posterior surface weakly imbricate. Metasomal terga polished, apical impressed areas weakly coriarious; punctures deep, close basally. T3–T6 apical impressed areas impunctate.

Pubescence. Head and mesosoma with sparse plumose hairs. Paraocular area below eye emargination with dense 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. 7C , 8C . Gonostylus slender, with short setae. Retrorse lobe long, narrow, attenuated apically.

Taxonomic notes. Lasioglossum foxii belongs to the nitidiusculum species-group ( Ebmer & Sakagami 1985). It is morphologically similar to western North American species of this group, including L. diatretum ( Vachal 1904) , L. synthyridis ( Cockerell 1906) (possibly a junior synonym of L. diatretum ), L. ruficorne ( Crawford 1907a) , L. vaporellum ( Cockerell 1910) , and L. pulveris ( Cockerell 1930) (possibly a synonym of L. ruficorne ). The western species seem to be morphologically and genetically distinct from L. foxii in the east. At least L. diatretum and L. ruficorne are valid species, but additional study of the western members of the group is needed. The only other member of this species group east of the Mississippi River is L. inconditum (see below).

The original name for L. foxii was preoccupied by Halictus gracilis Morawitz (1860) . The latter is now a junior subjective synonym of L. lucidulum ( Schenck 1861) . In Robertson’s (1890) original description New Hampshire, Illinois, Nevada, and California are listed as collection localities. Nevadan and Californian individuals from the type series almost certainly belong to one or more of the related congeners listed above.

Biology. This species is polylectic ( Moure & Hurd 1987). Knerer and Atwood (1962) report gregarious nesting of L. foxii in sandy areas. There are no published accounts of its sociality, but it is believed to be solitary based on its phylogenetic affiliations.

DNA barcodes. Eight specimens sequenced (maximum intraspecific p-distance: 1.0%). DNA barcodes from L. foxii cluster separately from related western species. Five fixed differences diagnose L. foxii relative to western relatives in the nitidiusculum group: 30(A), 180(G), 216(A), 318(A), 348(A). The minimum p-distance between DNA barcodes of L. foxii to its eastern relative L. inconditum is 6.7%. In the east, L. foxii can be distinguished from L. inconditum by 38 fixed differences: 9(C), 54(A), 73(C), 79(G), 81(C), 117(T), 120(T), 216(G), 219(C), 246(T), 276(A), 309(A), 318(G), 345(A), 348(G), 354(T), 375(T), 378(C), 384(T), 393(C), 396(T), 399(A), 402(T), 405(T), 423(T), 432(T), 441(T). 456(T), 465(A), 474(C), 535(T), 537(A), 546(T), 553(G), 591(T), 600(C), 603(C), and 645(T) (see Table 2). Three fixed substitutions distinguish L. foxii from all other species included herein: positions 318(G), 348(G), and 378(C).

Range. Fig. 20 .

Material examined. 1868 (1532 females, 336 males). Deposited in ABS, ACNS, AMNH, ANSP, BBSL, CMNH, CNC, CUIC, MCPM, MSUC, PMAE, PMNH, and ROMent .

CANADA. NEW BRUNSWICK: Charlotte Co.: St. Andrews; York Co.: Fredericton; NOVA SCOTIA: Colchester Co.: Truro; Hants Co.; Kings Co.: Kentville; ONTARIO: Elgin Co.: St. Thomas; Haliburton Co.: Algonquin P.P., by Crossbar Lk.; Hastings Co.: Frankford; Marmora; Lanark Co.: Almonte, 3 km NE; Middlesex Co.: Lobo; Strathroy; Muskoka Reg.: Dorset, Huntsville area; Muskoka; Port Sydney; National Capital Reg.: Constance Bay; Ottawa; Quarries; Niagara Reg.: Jordan; Niagara Falls; Oxford Co.: Ingersoll; Parry Sound Dist.: Waubamik; Peel Reg.: Credit Forks; Toronto Div.: Leaside; Toronto; York Reg.: Purpleville; PRINCE EDWARD ISLAND: Kings Co.: Albion Cross; Mt. Hope; St. Patrick Rd.; Queens Co.: Belle River; Dromore; St. Andrews; QUEBEC: Capitale-Nationale Reg.: Quebec City; Mauricie Reg.: Knowlton, Shawinigan; Lac Mondor, Ste. Flore; Montérégie Reg.: St. Paul-d’Abbotsford; Outaouais Reg.: Aylmer; Aylmer, Queens Pk.; Fort-Coulonge; Gatineau Pk.; Hull; Kazabezua.

USA. CONNECTICUT: Litchfield Co.: Colebrook; New Haven Co.: Branford; New Haven; GEORGIA: Rabun Co.: Burton; Rabun Bald; Satolah; Union Co.: Suches; White Co. : Yonah Mt.; ILLINOIS: Cook Co.: Tinley Park; Macoupin Co.: Carlinville; KANSAS: Douglas Co.: Lawrence, 7 mi. NW; MAINE: York Co.: Old Orchard; MARYLAND: Allegany Co.: Flintstone, 6 mi. E; MASSACHUSETTS: Belknap Co.: Meredith; Berkshire Co.: N. Adams; Essex Co.: Andover; Franklin Co.: Hawley; Grafton Co.; Hampden Co.: Chester; Hampshire Co.: Holyoke Range S.P.; Mt. Holyoke; Middlesex Co.: Holliston; Lexington; Waltham; Norfolk Co.: Needham; Suffolk Co.: Forest Hills; Sullivan Co.; Worcester Co.: Petersham; Royalston; MICHIGAN: Barry Co.: Yankee Springs Game Area; Berrien Co.: Warren Dunes S.P.; Crawford Co.: Frederic; Dickinson Co.; Ingham Co.: Holt, 2 mi. SW; East Lansing; Kalamazoo Co.: Gull Lake Biol. Sta.; Kalaska Co.; Lake Co.; Manistee Co.: Kaleva; Montcalm Co.: Langston; Montmorency Co.; Oscoda Co.: Luzerne; MISSOURI: St. Louis Co.: Tyson Res. Sta., nr. Eureka; NEBRASKA: Custer Co.; NEW HAMPSHIRE: Belknap Co.: Meredith; Meredith Ctr.; Cheshire Co.: Jaffrey; Grafton Co.: Bethlehem; Sullivan Co.; NEW YORK: Albany Co.: Colonie; Huyck Preserve, nr. Rensselaerville; Westerlo, 2 mi. NW; Cayuga Co. : Aurora, Long Point S.P. ; Fair Haven Beach S.P.; Great Gully; Delaware Co.: Deposit; Essex Co.: Keene Valley; Genesee Co.; Herkimer Co.: Cold Brook; Jefferson Co.: Perry; Lewis Co.: Tug Hill; Madison Co.: Chittenango, 4 mi. N; Monroe Co.; Nassau Co.: Bethpage S.P.; Onondaga Co. : Syracuse; Orange Co.; Schuyler Co.; Hector Land Use Area, W of Reynoldsville; Suffolk Co.: Commack; Sullivan Co.: Beaver Hill; Tompkins Co.: Caroline, Speed Hill; Dryden, gravel pit; Ellis Hollow, 6 mi. E of Ithaca; Enfield, Teeter Rd.; Freeville; Ithaca; Ithaca, Buttermilk Falls S.P.; Ithaca, Cornell; Ithaca, Monkey Run; Ithaca, Robert H. Treman S.P.; Ithaca, Six-Mile Creek; McLean; McLean, 1 mi. S; Michigan Hollow, 5 mi. S Danby; Washington Co.; NORTH CAROLINA: Alleghany Co.: Scenic Hwy.; Ashe Co.: Scenic Hwy.; Avery Co.: Grandfather Mt.; Cabarrus Co.: Mt. Mitchell; Haywood Co.: Waynesville; Jackson Co.: Whiteside; Macon Co.: Highlands; Wayah Bald; McDowell Co.: Blue Ridge Pkwy.; Swain Co.: Andrews Bald; Wilkes Co.: Moravian Falls; Scenic Hwy.; Yancey Co.: Mt. Mitchell; NORTH DAKOTA: Cass Co.: Fargo; OHIO: Franklin Co.: PENNSYLVANIA: Allegheny Co: Harmarville: Pittsburgh; Clinton Co.: Tamarack; Erie Co.: Erie; Fayette Co: Ohio Pyle; Pike Co.; Potter Co.; Westmoreland Co.: Pleasant Grove, 2 mi. S; Powdermill N.R.; Rector, 3 mi. S; TENNESSEE: Blount Co.: Cades Cove; VERMONT: Addison Co.; VIRGINIA: Arlington Co.: Arlington; Bennington Co.; Carroll Co.: Laurel Fork; Fairfax Co.: Dunn Loring; WEST VIRGINIA: Hardy Co.: Lost River S.P.; Jefferson Co.: Millville; Pendleton Co: Spruce Knob; Raleigh Co.; Randolph Co: Cheat Mt.; WISCONSIN: Milwaukee Co.: Milwaukee; Wauwatosa, Menomonee Valley; Pierce Co.: Maiden Rock.

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 18. Lateral habitus of female Lasioglossum (Hemihalictus) foxii (Robertson). Scale bar = 1 mm.

FIGURE 19. Lateral habitus of male Lasioglossum (Hemihalictus) foxii (Robertson). Scale bar = 1 mm.

FIGURE 20. Distribution map of Lasioglossum (Hemihalictus) foxii (Robertson). Heat map indicates predicted suitable range based on maximum entropy niche-modelling. Black circles indicate actual geo-referenced specimen records.

FIGURE 75. Propodeum and metapostnotum of female Lasioglossum. (A) L. nelumbonis showing appressed hairs. (B) L. quebecense showing strong propodeal carinae. (C) L. foxii showing weak-absent propodeal carinae.

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.

FIGURE 82. Propodeum, metapostnotum and anterior surface of T1 of female Lasioglossum (Hemihalictus). (A) L. lustrans showing fine metapostnotal sculpture and subappressed hairs on T1. (B) L. foxii showing metapostnotal rugae not reaching posterior dorsal margin. (C) L. inconditum showing metapostnotal rugae reaching posterior dorsal margin.