Lasioglossum (Dialictus) sagax (Sandhouse)

Gibbs, Jason, 2010, Revision of the metallic species of Lasioglossum (Dialictus) in Canada (Hymenoptera, Halictidae, Halictini) 2591, Zootaxa 2591 (1), pp. 1-382 : 286-290

Lasioglossum (Dialictus) sagax (Sandhouse)

( Figures 199A–E , 200A–F )

Halictus (Chloralictus) sagax Sandhouse, 1924: 25 . ♂.

Holotype. ♂ USA, Colorado, Boulder , 28.vii.1908 (S.A. Rohwer); [ NMNH: 26422]. Examined.

Halictus (Chloralictus) accentus Sandhouse, 1924: 38 . ♂. [new synonymy]

Holotype. ♂ USA, Colorado, Boulder, University of Colorado Campus , 1.viii.1908 (S.A. Rohwer); [ NMNH: 26442]. Examined.

Taxonomy. Michener, 1951: Lasioglossum (Chloralictus) accentum , p. 1111, L. (C.) sagax , p. 1117 (catalogue); Hurd, 1979: Dialictus accentus , p. 1963, D. sagax , p. 1971 (catalogue); Moure & Hurd, 1987: Dialictus accentus , p. 87, D. sagax , p. 128 (catalogue).

Diagnosis. Females of L. sagax can be recognised by the diagnostic combination of dense punctures of the supraclypeal area, imbricate mesoscutum with moderately sparse and deep punctures on the central disc (i=1–2d), rugulose mesepisternum, strong rugae on metapostnotum reaching the posterior margin, incomplete acarinarial fan and polished, T1 dorsally and T2 apicomedially with sparse punctures, metasomal terga brown, T2 basolaterally and T3–T4 entirely with moderately abundant tomentum, dense apical fringes on T3–T4. They are most similar to L. admirandum and L. ephialtum . Female L. admirandum have distinct punctures on dorsal surface of T1 and apicomedial portion of T2. Female L. ephialtum have moderately weak fringes on T3–T4 and shallow punctures on central disc of mesoscutum.

Males of L. sagax are similar to females but may be further distinguished by the yellow band on the apex of the clypeus, dense facial pubescence obscuring the surface below, mostly brownish yellow tibiae and tarsi and polished, moderately polished mesoscutum due to lack of microsculpture, brown metasomal terga with the apical halves impunctate. They are most similar to L. admirandum which have the mesoscutum dull due to microsculpture.

Description. FEMALE. Length 5.67–7.20 mm; head length 1.56–1.66 mm; head width 1.61–1.70 mm; forewing length 4.33–4.58 mm.

Colouration. Head and mesosoma pale golden green or bluish green. Clypeus with apical half blackish brown and basal half, and supraclypeal area golden. Antenna dark brown, flagellum with ventral surface reddish brown to orange-yellow. Tegula reddish brown to translucent brownish yellow. Wing membrane subhyaline, venation and pterostigma pale brownish yellow. Legs brown, medio- and distitarsi reddish brown. Metasoma dark brown, terga and sterna with apical margins translucent brownish yellow.

Pubescence. Dull white. Moderately sparse. Head and mesosoma with moderately dense woolly hairs (1– 1.5 OD), longest on genal beard, metanotum and mesopleuron (2–2.5 OD). Lower paraocular area and gena with sparse tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (2– 2.5 OD). Metasomal terga with moderately sparse, fine setae. T1 acarinarial fan strong with dorsal opening, approximately as wide as lateral hair patches. T2 basolaterally and T3–T4 entirely with moderately dense tomentum partially obscuring surface. T2 apicolateral and T3–T4 apical margins with moderately strong fringes.

Surface sculpture. Face weakly imbricate, punctation moderately fine. Clypeus with apical half polished, punctation sparse (i=1–3d). Supraclypeal area with punctation dense (i≤d). Lower paraocular area punctation dense (i≤d). Antennocular area punctation moderately dense (i≤1.5d). Upper paraocular area, frons and ocellocular area reticulate-punctate. Gena lineolate. Postgena imbricate. Mesoscutum imbricate-tessellate, polished submedially, punctation fine, moderately sparse between parapsidal lines (i=1–2d), dense laterad of parapsidal line (i≤d), and reticulate on anterolateral portions. Mesoscutellum similar to mesoscutum, submedial portion punctation sparse (i=1–4d). Axilla punctate. Metanotum imbricate. Preëpisternum rugulose. Hypoepimeral area rugulose. Mesepisternum dorsal portion rugulose and ventral portion ruguloso-imbricate. Metepisternum with dorsal 2/5 striate, ventral 3/5 imbricate. Metapostnotum strongly rugoso-striate, reaching posterior margin. Propodeum with dorsolateral slope ruguloso-imbricate, lateral surface weakly rugulosoimbricate, posterior surface tessellate. Metasomal terga polished except apical margins faintly coriarious. T1 dorsal surface nearly impunctate. T2–T4 with punctation on basal halves moderately sparse (i=2–3d), sparse on apical halves (i=2–4d).

Structure. Head moderately wide (length/width ratio = 0.94–0.99). Eyes convergent below (UOD/LOD ratio = 1.24–1.29). Clypeus 2/3 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 3–4 teeth. Metapostnotum moderately elongate (MMR ratio = 1.24–1.32), posterior margin weakly angled onto posterior surface. Propodeum with oblique carina weak, lateral carina weak, not reaching dorsal margin.

MALE. Similar to female except for the usual secondary sexual characters and as follows. Length 5.25– 5.92 mm; head length 1.49–1.58 mm; head width 1.46–1.56 mm; forewing length 3.97–4.09 mm.

Colouration. Labrum yellow. Mandible yellow. Clypeus apical margin yellow. Flagellum ventral surface orange-yellow. Tibiae brownish yellow except dorsal surface with large brown patch or brownish yellow limited to apical and basal patches. Tarsi brownish yellow.

Pubescence. Face below eye emargination with dense tomentum obscuring surface. T2–T4 basolaterally with sparse tomentum. S3–S5 apicolaterally with dense plumose hairs (1 OD).

Surface sculpture. Mesoscutum weakly imbricate-tessellate. Mesoscutellum tessellate, submedial punctation moderately dense (i=1–2d). Metanotum rugose. Propodeum dorsolateral slope and lateral and posterior faces rugose. Metasomal terga with apical halves impunctate.

Structure. Head moderately elongate (length/width ratio = 1.00–1.02). Eyes strongly convergent below (UOD/LOD ratio = 1.44–1.45). Clypeus 3/4 below suborbital tangent, apicolateral margins weakly convergent. Antennal sockets distant (IAD/OAD> 1.3). Pedicel shorter than F1. F2 length 1.7–1.8X F1. F2–F10 moderately elongate (length/width ratio = 1.50–1.71). Metapostnotum moderately elongate (MMR ratio = 1.21–1.29), posterior margin sharply angled onto posterior surface.

Terminalia . S7 with median lobe large, clavate, apex rounded ( Fig. 200F ). S8 with apicomedial margin strongly convex ( Fig. 200F ). Genitalia as in Fig. 200D–E . Gonobase with ventral arms narrowly separated. Gonostylus small, dorsal setae elongate. Retrorse lobes elongate, weakly attenuated apically.

Range. Nova Scotia, west to Alberta, south to Colorado ( Fig. 201 ).

Additional material examined. CANADA: ALBERTA: 1♀ Waterton Lakes N.P., Cardston Entrance , 22.vi–6.vii.2000 ; 1♀ Waterton Lakes N.P., Cardston Entrance , 20.vii–3.viii.2000 ; 1♀ Waterton Lakes N.P., Cardston Entrance , 3–17.viii.2000 ; 1♀ Waterton Lakes N.P., Cardston Entrance , 13.viii.1999; [ PMAE] ; BRITISH COLUMBIA: 3♀ Okanaga-Similkameen Reg. Dist., Camp Osoyoos , N49.0895 W119.5358, 280 m, 22.iv.2009 (L. R. Best) ; MANITOBA: 1♀ 1 km NW of Winnepegosis, Hwy 20, N51.6511 W099.94527, 251 m, 16.vi.2007 (Goulet & Boudreault) ; 1♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°40´51´´ N099°33´15´´, 24.v.2005 (A.M. Patenaude) ; 3♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°40´51´´ N099°33´16´´, 16.v.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°40´51´´ N099°33´16´´, 24.v.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°40´51´´ N099°33´16´´, 20.vii.2005 (A.M. Patenaude) ; 1♂ allotype, YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°40´51´´ N099°33´16´´, 8.viii.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°41´28´´ N099°34´29´´, 16.v.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°41´28´´ N099°34´29´´, 24.v.2005 (A.M. Patenaude) ; 1♀ YellowQuill Mxd. Grass Prairie Preserve, near Treesbank , N49°41´28´´ N099°34´29´´, 26.vii.2005 (A.M. Patenaude) ; NOVA SCOTIA: 1♀ Kings Co., Avonport , N45.1198 W064.273, 20.vi.2002 (C. Sheffield) ; 1♀ Kings Co., Avonport , N45.1198 W064.273, 17.viii.2002 (C. Sheffield); [ PCYU] ; SASKATCHEWAN: 4♂♂ Sask. Landing , 23.vii.1956 (O. Peck) ; 11♀ Saskatoon , 28.iv.1949 (A. R. Brooks); [ CNC] ; USA: WISCONSIN: 1♀ Door Co., Ridges Road , N45.06978 W087.11784, 29.vi.2006 (A. Wolf) ; 1♂ Manitowoc Co., Kingfisher Farm (beach), N43.96172 W087.70112, 20.vii.2004 (A. Wolf); [ PCYU] .

Floral records. BRASSICACEAE : Cakile edentula , ROSACEAE : Potentilla .

Comments. Common. First description of female. This species belongs to the L. viridatum species-group. DNA barcodes for this putative species show three distinct haplotypes, even among the Manitoba material taken from a single study area ( Patenaude 2007). Additional study of this species is needed.

Figures

FIGURE 199. Lasioglossum sagax (Sandhouse). Female (A) lateral habitus; (B) dorsal habitus; (C) face; (D) mesoscutum; (E) metasomal terga. Scale bars, A–C = 1 mm.

FIGURE 200. Lasioglossum sagax (Sandhouse). Male (A) lateral habitus; (B) dorsal habitus; (C) face; (D) ventral view of genital capsule; (E) dorsal view of genital capsule; (F) S7, S8. Scale bars, A–C = 1 mm, F = 0.5 mm.

FIGURE 201. Distribution of Lasioglossum sablense (star), L. sagax (light grey) and L. sandhousiellum (dark grey).