Lasioglossum (Dialictus) surianae (Mitchell)

Gibbs, Jason, 2011, Revision of the metallic Lasioglossum (Dialictus) of eastern North America (Hymenoptera: Halictidae: Halictini), Zootaxa 3073, pp. 1-216 : 185-187

Lasioglossum (Dialictus) surianae (Mitchell)

( Figures 200–203 )

Dialictus surianae Mitchell, 1960: 420 . Ƥ.

Holotype. Ƥ USA, Florida, Plantation Key, 27.xi.1955 (H.V. Weems, Jr.); [ FCSA]

Taxonomy. Krombein, 1967: Lasioglossum (Dialictus) surianae , p. 466 (catalogue); Moure and Hurd, 1987: Dialictus surianae , p. 132 (catalogue).

Diagnosis. Both sexes of L. surianae can be recognised by the following diagnostic combination: tegula enlarged, pale yellow, with posterior angle ( Figs. 201 , 203 ), and fine punctation. Female L. surianae have metasomal terga reddish orange ( Fig. 200 A).

Redescription. FEMALE. Length 4.31–4.42 mm; head length 1.22–1.33 mm; head width 1.27–1.36 mm; forewing length 2.94–2.96 mm.

Colouration. Head and mesosoma pale golden green. Labrum and lower paraocular area orange. Mandible brownish yellow. Clypeus with apical half orange to reddish. Antenna brown, flagellum with ventral surface brownish orange. Tegula orange. Wing faintly dusky, venation and pterostigma reddish brown. Legs brown, except tarsi brownish yellow. Metasoma brownish red, terga and sterna with apical margins brownish yellow.

Pubescence. Dull 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). Gena with sparse subappressed tomentum. Propodeum with moderately dense plumose hairs on lateral and posterior surfaces (1.5–2 OD). Metasomal terga with sparse, fine hairs. T1 acarinarial fan complete. T2–T4 basolaterally with very sparse tomentum. T2 apicolateral and T3–T4 apical margins with very sparse fringes, virtually absent.

Surface sculpture. Face imbricate, punctation moderately strong. Clypeus polished, basal margin imbricate, punctation moderately dense (i=1–1.5d). Supraclypeal area with punctation moderately sparse (i=1–3d). Lower paraocular area punctation dense (i<d). Antennocular area punctation moderately dense (i≤1.5d). Upper paraocular, frons and ocellocular area reticulate-punctate. Gena and postgena lineolate. Mesoscutum tessellate, punctation fine, moderately dense on central disc (i=1–2d), dense laterad of parapsidal line and on anterolateral portion (i<d). Mesoscutellum similar to mesoscutum, submedial punctation moderately dense (i=1–1.5d). Axilla punctate. Metanotum imbricate. Preëpisternum, hypoepimeral area, and mesepisternum reticulate-rugulose. Metapostnotum with anastomosing rugae. Propodeum with dorsolateral slope striate, lateral and posterior surface imbricate-tessellate. Metasomal terga weakly polished except T1 declivitous surface coriarious, punctation very fine, on basal halves moderately dense (i=1.5d), sparser on apical halves (i=1–2d).

Structure. Head moderately wide (length/width ratio = 0.96–0.97). Eyes convergent below (UOD/LOD ratio = 1.26– 1.27). 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. Tegula elongate, angulate posteromedially. Inner metatibial spur pectinate with 2–3 branches. Metapostnotum relatively elongate (MMR ratio = 1.15), posterior margin weakly angled onto posterior surface. Propodeum with oblique carina weak, lateral carina weak, not reaching dorsal margin.

MALE (metasoma not examined). Similar to female except for the usual secondary sexual characters and as follows. Head length 1.28 mm; head width 1.28 mm; forewing length 2.94 mm.

Colouration. Mandible, flagellum ventral surface, tegula, tarsi brownish yellow.

Pubescence. Lower paraocular area tomentum obscuring surface.

Surface sculpture. Clypeus densely punctate (i=d). Mesepisternum polished, punctate (i=d). Propodeum posterior surface punctate.

Structure. Head elongate (length/width ratio = 1.00). Eyes strongly convergent below (UOD/LOD ratio = 1.52). Clypeus 2/3 below suborbital tangent, apicolateral margins subparallel. Antennal sockets distant (IAD/OAD> 0.7). Frontal line carinate, ending 2 OD below median ocellus. Pedicel shorter than F1. F2 length 1.6X F1. F2–F10 moderately elongate (length/width ratio = 1.30–1.45). Metapostnotum elongate (MMR ratio = 1.28), posterior margin rounded onto posterior surface.

Terminalia . Not examined.

Range. Southern Florida, Bahamas ( Fig. 199 ).

Additional material examined. BAHAMAS: 2ƤƤ Great Exuma, Georgetown N., Isl. #26, N23.5 W75.75, 8.viii.2004 (M.F. Keller); [ PCYU]; 13 Gorda Cay, N26°05ʹ W77°32ʹ, 26.vi–7.vii.1998 (T. Peak); 1Ƥ Gorda Cay, N26°05ʹ W77°32ʹ, 7–16.vii.1998 (T. Peak); [ UCFC]. USA: FLORIDA: 1Ƥ paratype Key Vaca, 28.xii.1955 (H.V. Weems, Jr.); 1Ƥ Monroe Co., Stock Island, 15.x.1963 (H.V. Weems, Jr.); Monroe Co., Big Pine Key, 23.vi.1971 (W.H. Pierce); 13 Monroe Co., Big Pine Key, 19.v.1971 (W.H. Pierce); [ CUIC].

Floral records. ASTERACEAE : Bidens pilosa ; CONVOLVULACEAE : Jacquemontia SURIANACEAE : Suriana maritima .

DNA Barcode. Available. Single sequence.

Comments. Rare.

Lasioglossum surianae belongs to the L. tegulare species group (equivalent to the L. parvum group of Eickwort (1988)). It is similar to the West Indian species L. gemmatum (Smith) .

Figures

FIGURE 199. Distribution map of Lasioglossum stuartense (square), L. surianae (stars) and L. tamiamense (circles).

FIGURE 200. Lasioglossum surianae (Mitchell) female, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 201. Lasioglossum surianae (Mitchell) female, dorsal view of mesosoma.

FIGURE 202. Lasioglossum surianae (Mitchell) male, (A) lateral habitus, (B) face. Scale bars = 1 mm.

FIGURE 203. Lasioglossum surianae (Mitchell) male, dorsal view of mesosoma.