Lasioglossum (Dialictus) tenax (Sandhouse)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 329-333

Lasioglossum (Dialictus) tenax (Sandhouse)

( Figures 223A–C , 224A–F )

Halictus (Chloralictus) tenax Sandhouse, 1924: 15 . ♀.

Holotype. ♀ USA, Colorado, Long Peak Inn , Colorado, 25.vi., (Cockerell); [ NMNH: 26406]. Examined.

Halictus (Chloralictus) meritus Sandhouse, 1924: 19 . ♀. [new synonymy]

Holotype. ♀ USA, Colorado, Halfway House, Pikes Peak , 30.v., on Fragaria, (Cockerell) ; [ NMNH: 26415]. Examined.

Dialictus disabanci Knerer and Atwood, 1966a: 882 . ♂. [new synonymy]

Holotype. ♀ CANADA, Ontario, Pearl, Thunder Bay Dist. , 20.viii.1963 on Anaphalis, (G. Knerer) ; [ ROM: 83869]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) meritum , p. 1115, L. (C.) tenax , p. 1118 (catalogue); Hurd, 1979: Dialictus disbanci (lapsus calami), p. 1966, D. meritus , p. 1968, D. tenax , p. 1972 (catalogue); Moure & Hurd, 1987: Dialictus disabanci , p. 99, D. meritus , p. 112, D. tenax , p. 134 (catalogue).

Diagnosis. See diagnosis for L. cattellae .

Redescription. FEMALE. Length 4.94–5.80 mm; head length 1.34–1.44 mm; head width 1.42–1.49 mm; forewing length 3.66–3.84 mm.

Colouration. Head and mesosoma greenish blue. Clypeus with apical 2/3 blackish brown and basal 1/3 green. Antenna dark brown, flagellum with ventral surface reddish brown. Tegula reddish brown to amber. Wing membrane subhyaline, venation and pterostigma pale reddish brown. Legs brown, medio- and distitarsi reddish brown. Metasomal terga with very faint metallic reflections, sterna brown, apical margins reddish to translucent yellowish brown

Pubescence. Dull white. Sparse. Head and mesosoma with moderately sparse woolly hairs (1–1.5 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Lower paraocular area and gena with very sparse subappressed tomentum. Propodeum with moderately sparse plumose hairs on lateral and posterior surfaces (2–2.5 OD). Metasomal terga with sparse, fine setae. T1 acarinarial fan complete, not reaching upper margin of declivitous surface. T2–T3 basolaterally and T4 entirely with sparse, scattered tomentum.

Surface sculpture. Face imbricate, punctation fine. Clypeus polished, basal margin weakly imbricate, punctation sparse (i=1–3d). Supraclypeal area with punctation sparse (i=1–3d). Lower paraocular area punctation moderately sparse (i=1–1.5d). Antennocular area punctation moderately sparse (i=1–2d). Upper paraocular area and frons reticulate-punctate. Ocellocular area finely punctate (i=1–2d). Gena lineolate. Postgena imbricate. Mesoscutum weakly imbricate, punctation fine, moderately sparse between parapsidal lines (i=1– 2d), dense laterad of parapsidal lines (i≤d), contiguous on anterolateral portion. Mesoscutellum polished, submedial punctation sparse (i=1–3d). Axilla punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area weakly polished, minutely punctate (i≤d). Mesepisternum weakly imbricate, distinctly punctate (i=1–2d). Metepisternum with dorsal third rugoso-striate, ventral portion imbricate. Metapostnotum incompletely striate. Propodeum with dorsolateral slope and posterior surface imbricate, lateral surface imbricatetessellate. Metasomal terga polished except apical impressed areas weakly coriarious, punctation on basal halves moderately sparse (i=2–3d), apical half impunctate (except along premarginal line).

Structure. Head moderately wide (length/width ratio = 0.95–0.97). Eyes convergent below (UOD/LOD ratio = 1.16–1.23). Clypeus ½ 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 2–3 teeth. Metapostnotum moderately elongate (MMR ratio = 1.17–1.24), posterior margin rounded onto posterior surface. Propodeum with oblique carina weak, lateral carina not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 4.21– 5.12 mm; head length 1.25–1.39 mm; head width 1.22–1.42 mm; forewing length 3.36–3.90 mm.

Colouration. Flagellum with ventral surface orange-yellow, paler on basal flagellomeres. Pterostigma brown. Tarsi orange-yellow.

Pubescence. Clypeus, and supraclypeal area with sparse tomentum. Lower paraocular area width moderately dense tomentum, largely obscuring surface. Sterna with sparse, erect hairs (1–1.5 OD).

Surface sculpture. Mesepisternum obscurely to distinctly punctate. Metapostnotum completely rugosostriate. Propodeum dorsolateral slope, and lateral and posterior surfaces rugose.

Structure. Head wide to round (length/width ratio = 0.96–1.02). Eyes strongly convergent below (UOD/ LOD ratio = 1.34–1.50). Antennal sockets distant (IAD/OAD> 1.5). Pedicel shorter than F1. F2 length 1.5– 1.6X F1. F2–F10 moderately elongate (length/width ratio = 1.50–1.60). Metapostnotum truncate (MMR ratio = 1.35–1.50), posterior margin sharply angled onto posterior surface.

Terminalia . S7 with median lobe columnar, apex rounded ( Fig. 224E ). S8 with apicomedial margin weakly convex ( Fig. 224E ). Genitalia as in Fig. 224E–F . Gonobase with ventral arms widely separated. Gonostylus small, dorsal setae elongate. Retrorse lobe elongate, weakly attenuated, recurved apically.

Range. Newfoundland west to Alaska, south to Colorado, Utah ( Fig. 225 ).

Additional material examined. CANADA: ALBERTA: 1♀ Calgary Heritage Pk., 20.v.1988 (L. Packer) ; 1♀ Calgary Ranchlands , 24.v.1988 (L. Packer); [ PCYU] ; 1♀ Dunvegan , 6–7.vii.1984 (Thormin, Spanton & Adamski); [ PMAE] ; 2♀ Waterton Lakes N.P., Cardston Ent. , 3–17.viii.2000 [ BDUC]; BRITISH COLUM- BIA: 1♀ Cariboo Reg. Dist., Alexandria, James Lk. FSR, Moffat Lk. , N52.664 W122.3822, 797 m, 13.viii.2008 (L. R. Best) ; NEWFOUNDLAND: 2♀ Colliers , 5.vii.2006 (M. Baird) ; 1♀ Colliers , 7.vii.2006 (M. Baird) ; 1♀ Colliers , 21.vii.2006 (M. Baird) ; NORTHWEST TERRITORIES: 1♀ S of Rae , N62.0131 W116.3047, 23.vi.2005 (C. Sheffield & A. Gunn); [ PCYU] ; ONTARIO: 1♂ paratype Hearst , 17.viii.1963 (G. Knerer) ; 1♀ paratype Pearl 20.viii.1963 (G. Knerer); [ CNC] ; 1♀ Hearst , 13.viii.1962 (G. Knerer) ; 1♂ Hearst , 17.viii.1963 (G. Knerer) ; 4♀ Kabinakagami R ., 17.viii.1963 (G. Knerer); 1♂ L. Superior, 29.vi.1961 (G. Knerer); 2♂♂ Pearl , 20.viii.1963 (G. Knerer) ; 2♂♂ Porquis , 10.viii.1961 (G. Knerer) ; 1♂ Red Lake , 15.viii.1962 (G. Knerer) ; 1♂ Quetico Park , 26.viii.1964 (G. Knerer) ; 1♀ 1♂ Red Lake Rd. , 19.viii.1963 (G. Knerer) ; 2♀ Temiskaming , 15.v.1962 (G. Knerer) ; 1♂ Upsala , 147. viii.1962 (G. Knerer); [ ROM] ; QUEBEC: 1♀ W of Normandin , N48°51´38.9´´ W72°37´0.9´´, 180 m, 8.vi.2009 (M. Chagnon); [ PCYU]; SASKATCH- EWAN: 1♀ Wood Mountain , 5.viii.1955 (C.D. Miller); [ CNC] ; YUKON TERRITORY: 7♀ Champagne (J. Taylor) ; 1♀ 1♂ Takhini Hot Springs , 22.vii.1992 (J. Taylor) ; 1♀ 5♂♂ Julie’s farm, 4.viii.1992 (J. Taylor); [ PCYU] ; USA: ALASKA: 1♀ Anderson, Hwy 3, N67˚17.677ʹ W149˚05.067ʹ, 235 m, 18.vii.2009 (Goulet & Boudreault); [ CNC] ; NORTH CAROLINA: 1♀ 1♂ Swain Co., Great Smoky Mountain N.P., Andrew’s Bald , N35.5396 W083.4942, 6.viii.2006 (J. Gibbs); [ GSNP] ; UTAH: 1♀ San Juan Co., La Sal Mountains, Warner Lake , 9400 ft., 29.vi.1999 (L. Packer); [ PCYU] .

Floral records. ASTERACEAE : Anaphalis , Aster , Epilobium , Solidago , Taraxacum , ROSACEAE : Fragaria , SALICACEAE : Salix .

Biology. Packer, 1994: (solitary behaviour).

Comments. Uncommon. This seems to an alpine/boreal species with an extensive range in Canada but limited to high elevations in the contiguous USA.

The holotypes of the three synonymous names do not differ and DNA barcode sequences show no variation across the continent. The similar species L. cattellae may be distinguished from L. tenax morphologically but not by DNA barcodes. The former name has priority should additional evidence show the morphological evidence is insufficient for recognising these as separate species (i.e. if it is due to caste differentiation). This seems unlikely see there is apparently little overlap in the distribution of the two putative species.

Figures

FIGURE 223. Lasioglossum tenax (Sandhouse). Female (A) lateral habitus; (B) dorsal habitus; (C) face. Scale bars, A– C = 1 mm.

FIGURE 224. Lasioglossum tenax (Sandhouse). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) T2, T3; (E) ventral view of genital capsule, S7, S8; (F) dorsal view of genital capsule. Scale bars, A–C = 1 mm, F = 0.5 mm.

FIGURE 225. Distribution of Lasioglossum tenax (light grey) and L. timothyi (dark grey).