Lasioglossum (Dialictus) bruneri (Crawford)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 76-80

Lasioglossum (Dialictus) bruneri (Crawford)

( Figures 77A–D , 78A–E )

Halictus Bruneri Crawford, 1902: 237 . ♀.

Holotype. ♀ USA, Nebraska, West Point , 10.vi.1901 (J.C. Crawford); [ NMNH: 8231]. Examined.

Halictus brimleyi Crawford, 1932: 71 . ♀.

Holotype. ♀ USA, North Carolina, Bryson City , 24.v.1923 on Ilex opaca (J.C. Crawford) ; [ NMNH: 40306]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) bruneri , p. 1112 (catalogue, synonymy); Mitchell, 1960: Dialictus bruneri ♂, p. 384 (redescription); Krombein, 1967: Lasioglossum (Dialictus) bruneri , p. 462 (catalogue); Hurd, 1979: Dialictus bruneri , p. 1964 (catalogue); Moure & Hurd, 1987: Dialictus bruneri , p. 92 (catalogue).

Diagnosis. Females of L. bruneri can be distinguished from all other Canadian Dialictus by the deeply excavated hypostomal cavity with widely divergent hypostomal carinae ( Fig. 77D ), strongly reflexed in lateral view. Female L. bruneri may be further recognised by the extremely strong sculpture of head and mesosoma and strong propodeal carinae. They are most similar to L. reticulatum , known only from the Eastern United States, which have the hypostomal carinae less divergent and not greatly reflexed.

Males of L. bruneri can be recognised by the rugose anterior margin of the mesoscutum, the coarsely rugose mesepisternum, and brown tibiae and femora. They are most similar to the USA species L. reticulatum which have extensive reddish brown colouration on the tibiae and apical and basal portions of the femora.

Redescription. FEMALE. Length 6.04–7.10 mm; head length 1.70–1.99 mm; head width 1.82–2.18 mm; forewing length 4.45–5.20 mm.

Colouration. Head and mesosoma green with bluish reflections. Mandible orange. Antenna blackish brown, flagellum with ventral surface brown. Tegula reddish brown. Wing membrane subhyaline, venation and pterostigma amber. Legs brown, tarsi reddish brown to amber. Metasoma blackish brown, terga and sterna with apical margins reddish brown.

Pubescence. Dull white to yellowish white. Moderately dense. Head and mesosoma with moderately dense woolly hairs (1–1.5 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Paraocular area with sparse subappressed hairs. Gena with sparse tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with sparse, fine setae. T1 acarinarial fan open above, not reaching dorsal margin of declivitous surface. T2 basolateral area obscured by dense tomentum. T3–T4 disc largely obscured by dense tomentum and with sparse, fringes. T2 apicolateral and T3–T4 apical margins with weak fringes.

Surface sculpture. Face polished, weakly imbricate, punctation strong. Clypeal punctation moderately dense (i=1–1.5d). Supraclypeal area and lower paraocular are punctation dense (i<d). Antennocular area rugose. Upper paraocular area and frons punctate-reticulate. Ocellocular area punctation irregular (i≤d). Gena and postgena coarsely striate. Mesoscutum polished, weakly imbricate, punctation very strong, distinctly separated medially (i≤d), rugoso-reticulate laterad of parapsidal line and anterolaterally. Mesoscutellum similar to mesoscutum, submedial punctation moderately sparse (i=1–2d). Axilla reticulate. Metanotum rugose. Preëpisternum and mesepisternum coarsely rugose. Metepisternum with dorsal half striate, ventral half imbricate. Metapostnotum coarsely striate, interstices polished and shining. Propodeum with dorsolateral slope and lateral and posterior surfaces coarsely rugose. Metasomal terga polished except apical margins coriarious, most evident on T3–T4, punctation fine and deep throughout (i=1–2d).

Structure. Head wide (length/width ratio = 0.92–0.93). Eyes convergent below (UOD/LOD ratio = 1.15– 1.18). Labral tubercle small. Mandible subapical tooth present. Clypeus 1/2 below suborbital line, apicolateral margins subparallel. Antennal sockets close (IAD/OAD <0.5). Frontal line carinate, ending <2 OD below median ocellus. Gena nearly as wide as eye. Hypostome deeply excavated, carinae widely divergent towards mandible bases ( Fig. 77D ), distinctly reflexed in lateral view. Pronotum with dorsolateral angle obtuse. Protrochanter depressed near base. Inner metatibial spur pectinate with 3–4 teeth. Metapostnotum delimited from remainder of dorsal surface weak carina. Metapostnotum moderately elongate (MMR ratio = 1.36–1.40), posterior margin separated from posterior surface by carina. Propodeum with oblique carina strong, lateral carina reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.49– 6.60 mm; head length 1.70–1.92 mm; head width 1.73–1.92 mm; forewing length 4.45–4.88 mm.

Colouration. Head and mesosoma dull metallic blue. Flagellum with ventral surface brownish yellow. Tegula dark brown. Wing membrane subhyaline, venation and pterostigma yellowish brown. Tarsi yellow. Metasoma blackish brown.

Pubescence. Face with tomentum obscuring lower paraocular area and partially obscuring clypeus, supraclypeal area, upper paraocular area and frons. S2–S3 with dense apical subappressed hairs and S4 with apicolateral subappressed hairs.

Surface sculpture. Strong throughout. Mesoscutellum reticulate. Metepisternum rugoso-striate. Metasomal terga with apical impressed margins impunctate.

Structure. Head moderately wide to round (length/width ratio = 0.97–1.00). Eyes strongly convergent below (UOD/LOD ratio = 1.47–1.52). Clypeus 2/3 below suborbital line, apicolateral margins subparallel. Antennal sockets distant (IAD/OAD> 1.1). Frontal line carinate, ending <2 OD below median ocellus. Hypostomal carinae only slightly divergent towards mandibles. Pedicel shorter than F1. F2 length 1.8–2.0X F1. F2–F10 moderately elongate (length/width ratio = 1.39–1.71). Metapostnotum moderately elongate (MMR ratio = 1.27–1.31), posterior margin sharply angled onto posterior surface.

Terminalia . S7 with median lobe clavate, sides concave, apex rounded ( Fig. 78D ). S8 with apicomedial margin weakly convex ( Fig. 78D ). Genitalia as in Fig. 78D–E . Gonobase with ventral arms narrowly separated. Gonostylus narrow and elongate, dorsal setae elongate. Retrorse lobes elongate, reflexed apically.

Range. Ontario south to Florida, west to Nebraska ( Fig. 79 ).

Additional material examined. CANADA: ONTARIO: 2♀ Norfolk Co., Pterophylla Plant Nursery , N42°38.404´W080°34.379´, 13–22.viii.2006 (P.J. Carson) ; USA: GEORGIA: 1♀ Hwy 157, 4 km N of Menlo, N33.541 W083.453, 26.v.2005 (A. Zayed) ; 1♀ Stone Mtn. , N33.799 W084.141, 27.v.2005 (A. Zayed) ; ILLINOIS: 1♀ Kankakee Co., Hooper Br. , 19.ix.2003 ( R. P. Jean) ; INDIANA: 1♀ Jasper Co., Prairie Border , 1.vii.2003 ( R. P. Jean) ; 1♀ Newton Co., Conrad , 17.vii.2003 ( R. P. Jean) ; MARYLAND: 2♀ Pr. George’s Co., N38.0434 W076.7963, 7–8.viii.2002 (H.W. Ikerd) ; 1♂ Pr. George’s Co., N38.949 W076.7318, 20–21.viii.2005 (Z. Riegel) ; NORTH CAROLINA: 1♀ Blue Ridge Parkway , 10 km N of Asheville, N35.663 W082.479, 4.vi.2005 (A. Zayed) ; 1♀ Richmond Co., N35.0107 W079.56667, 19.v.2006 (S.W. Droege) ; SOUTH CAROLINA: 1♀ Chesterfield Co., N34.5691 W080.22023, 18.v.2006 (S.W. Droege); [ PCYU] ; TENNESSEE; Great Smoky Mtn. N.P., Cades Cove, Mill Creek , N35.58276 W083.8371, 5.viii.2006 (J. Gibbs); [ GSNP] ; VIRGINIA: 1♀ 1♂ Assateague I., N37.9144 W075.3379, 30.vi–1.vii.2006 (S.W. Droege) ; WEST VIRGINIA: 1♀ Hampshire Co., N39.2325 W078.5174, 29–30.v.2005 (S.W. Droege); [ PCYU] .

Floral records. ANACARDIACEAE : Rhus , APIACEAE : Eryngium , AQUIFOLIACEAE : Ilex opaca , ASTERACEAE : Chyrsanthemum, Rudbeckia , Senecio balsamitae , Solidago , Taraxacum , Vernonia , CAN- NACEAE: Canna , CELASTRACEAE : Euonymus , FABACEAE : Chamaecrista fasciculata , Mimosa microphylla , HYDRANGEACEAE : Hydrangea , IRIDACEAE : Gladiolus , NYCTAGINIACEAE : Mirabilis jalapa , POLYGONACEAE : Polygonum , ROSACEAE : Amelanchier , Crataegus , Fragaria , Photinia , Prunus , SOLANACEAE : Nicandra physalodes , SYMPLOCACEAE : Symplocos .

Biology. Bohart, 1941: (stylopization); Hopwood, 2007: (cyclops mutant).

Comments. Uncommon in Canada. Some Midwestern individuals have the hypostomal carinae less strongly divergent and may be mistaken for L. reticulatum .

Figures

FIGURE 77. Lasioglossum bruneri (Crawford). Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) hypostome. Scale bars, A–C = 1 mm.

FIGURE 78. Lasioglossum bruneri (Crawford). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule, S7, S8; (E) dorsal view of genital capsule. Scale bars, A–C = 1 mm, E = 0.5 mm.

FIGURE 79. Distribution of Lasioglossum bruneri (light grey), and L. brunneiventre (dark grey).