Lasioglossum (Dialictus) luciae, Gibbs & Bass & Morgan, 2022

Gibbs, Jason, Bass, Amber & Morgan, Katherine, 2022, Habralictus and Lasioglossum of Saint Lucia and Saint Vincent and the Grenadines, Lesser Antilles (Hymenoptera, Apoidea, Halictidae), ZooKeys 1089, pp. 125-167 : 125

Lasioglossum (Dialictus) luciae sp. nov.

Figs 5 , 6

Holotype.

Saint Lucia • Castries District • Piton Flore, Station no. 26, 10.I.1975, leg. J. Hance & G. Whitmyre (♂ FSCA).

Paratypes.

Saint Lucia • Castries District • Castries, 0-210 m, VIII.1976, N.L.H. Krauss (2 ♀ AMNH); Castries, 10-22.IX.1919, leg. J.C. Bradley (2 ♂ USNM) • Micoud District • Escap Community, Fond Bay at beach, 13.8316, -60.893, 1 m, 8.V.2009, leg. C.M. Delphia and J.B. Runyon (1 ♀ MTEC).

Diagnosis.

Lasioglossum luciae is one of only two L. (Dialictus) known from St. Lucia. It can be distinguished from L. (D.) dominicense by the larger size and longer head. It resembles L. kilpatrickae Gibbs, 2016 from Dominica and both L. plumbeum (Ashmead, 1900) and L. sanctivincenti (Ashmead, 1900) from Saint Vincent and the Grenadines.

Females of L. luciae and L. kilpatrickae are very similar and definitive characters for distinguishing them are not currently known. The gena of L. luciae may be more distinctly lineolate (Fig. 5D ) and T1 more distinctly coriarious (Fig. 5E ), but too few specimens are available of each species to be sure these characters are consistent. Both L. luciae and L. kilpatrickae are easily distinguished from L. plumbeum and L. sanctivincenti by absence of punctation on the apical impressed areas of T2, occurring only obscurely on the lateral portions. In contrast, both L. plumbeum and L. sanctivincenti have distinct, albeit fine punctures across the apical impressed areas of T2.

The male of L. luciae differs from L. kilpatrickae by the less abundant tomentum of the face (Fig. 6C ), which only weakly obscures the lower paraocular area, more evident microsculpture on the medial portion of the mesoscutum and anterior face of T1, and the relatively dense punctures on T1-T3, which end near the border of the apical impressed area, such that at least two thirds of the segments are densely punctate. Lasioglossum kilpatrickae has tomentum obscuring the lower paraocular area and proximal portion of the clypeus (Fig. 7B ). The mesoscutum has microsculpture between punctures limited to the anterior portion and is largely polished on the anterior face of T1. Furthermore, the punctation of T1-T3 is weak distally such that nearly half the longitudinal length of the segment is sparsely punctate to impunctate. T1 has a nearly impunctate medial line.

Description.

Female (n = 2). Length 5 mm; head length 1.4 mm; head width 1.4 mm; intertegular distance 1.0 mm; wing length 1.7 mm.

Colouration. Head and mesosoma dull metallic blue-green. Clypeal apex dark brown, base yellow. Labrum reddish brown to orange. Mandible orange with black base and red apex. Flagellum dark brown, F2-F11 orange-brown ventrally. Pronotal lobe reddish brown. Tegula reddish brown. Wing membrane hyaline, veins with subcosta brown to dark brown, otherwise amber. Legs brown, except medio- and distitarsi and portions of metabasitarsus reddish brown. Metasoma blackish brown, apical impressed area reddish brown.

Pubescence. Body with sparse pilosity, dull white to faintly yellowish. Tomentum on gena near eye, pronotum dorsolateral angles and lobe, narrow basolateral patches of T2-T3 and sparsely on T4. Mesoscutal pilosity sparse, erect. Wing setae dark. Acarinarial fan complete, dense. T2 fringes absent, sparse laterally, T3 fringes absent, sparse laterally.

Surface sculpture. Clypeal punctures sparse (IS = 1-4 PD), becoming moderately dense in basal third (IS = 1-2 PD), interspaces polished. Supraclypeal area punctures sparse (IS = 1-3 PD), interspaces weakly imbricate. Paraocular area punctures dense (IS <1 PD), except near antenna, interspaces imbricate. Frons punctures contiguous. Vertex punctures sparse, interspaces polished. Gena lineolate, postgena lineolate. Tegula punctures obscure. Mesoscutal punctures moderately dense (IS = 1 PD), becoming sparser submedially (IS = 1-1.5 PD) and denser laterad of parapsidal lines (IS ≤ 1 PD), interspaces imbricate, polished laterally; mesoscutellar punctures as in mesoscutum with submedial impunctate area, interspaces imbricate. Metapostnotal rugae strong, anastomosing or subparallel, reaching margin, sculpture imbricate. Pre-episternum rugulose-punctate. Hypoepimeral area densely punctate, interspaces polished. Mesepisternum distinctly punctate. Metepisternum lineolate dorsally, reticulate ventrally. Propodeal lateral face imbricate, sparsely punctate; posterior face imbricate, sparsely punctate. T1 anterior face coriarious; T1 dorsal surface punctures moderately dense (IS = 1-3 PD), absent or very sparse in large apicolateral oval patches, interspaces polished. T2 disc punctures moderately dense (IS = 1-3 PD), interspaces polished, rim impunctate, surface weakly coriarious.

Structure. Face length/width ratio 0.86 ( ± 0.01 SD). UOD/LOD ratio 1.21 ( ± 0 SD). Clypeus projecting ~75% below suborbital tangent; apicolateral denticles rounded knobs. Supraclypeal area length/width ratio 2.06 ( ± 0 SD). Hypostomal carinae parallel. Pronotal angle obtuse. Mesoscutum length/width ratio 0.83 ( ± 0.01 SD); mesoscutum/mesoscutellum length ratio 2.63 ( ± 0.1 SD); mesoscutellum/metanotum length ratio 1.66 ( ± 0.01 SD); metanotum/metapostnotum length ratio 0.75 ( ± 0.04 SD). Lateral propodeal carinae nearly reaching dorsal margin; oblique carina distinct. Tegula shape ovoid. Forewing with three submarginal cells. Distal hamuli arranged 2-1-2. Inner metatibial spur pectinate, with four branches not including apex of rachis, proximal branch much longer than width of rachis. Metasoma ovoid, apical impressed area medially ~ 1/2 longitudinal length of basal area.

Male (n = 3). Length 4.4-4.5 mm; head length 1.30-1.35 mm; head width 1.29-1.30 mm; intertegular distance 0.87-0.94 mm. Similar to female with usual sex-associated modifications.

Colouration. Head and mesosoma blue-green. Clypeal apex reddish brown. Labrum reddish brown. Mandible brown, orange apically. Flagellum brown, light brown ventrally. Pronotal lobe reddish brown. Tegula orange. Wing membrane hyaline, veins dark brown. Legs brown with reddish brown tarsi. Metasoma blackish brown, apical impressed areas reddish brown.

Pubescence. Body sparse pilosity, dull white to faintly yellowish. Tomentum moderately dense on lower paraocular area, sparse on clypeus, dense on pronotal lobe. Mesoscutal pilosity thin. Sternal pilosity short (1 OD), moderately plumose, sparse, erect. Wing setae dark, short, sparse.

Surface sculpture. Clypeal punctures dense (IS ≤ 1 PD), interspaces polished. Supraclypeal area punctures sparse (IS = 1-2 PD), interspaces polished. Paraocular area punctures dense (IS ≤ 1 PD), interspaces weakly imbricate around antenna socket, otherwise shiny. Frons punctate-reticulate. Gena punctulate-lineolate, postgena sculpture lineolate. Tegula mostly impunctate. Mesoscutal punctation moderately sparse medially (IS = 1-2 PD), denser laterad of parapsidal lines, interspaces weakly imbricate, polished laterally. Mesoscutellar punctation moderately sparse (IS = 1-2 PD), becoming denser on margins. Metanotum punctate. Metapostnotum incompletely rugulose, margin weakly tessellate. Pre-episternum sculpture punctate. Hypoepimeral area closely punctate (IS ≤ 1 PD), interspaces polished. Mesepisternum distinctly punctate (IS ≤ 1 PD), interspaces shiny. Metepisternum lineolate dorsally, punctate-reticulate ventrally. Propodeal lateral face tessellate-punctate, dorsolateral slope punctate. Propodeal posterior face sculpture tessellate-punctate. T1 anterior face weakly coriarious. T1 dorsal surface evenly punctate (IS = 1-2 PD), interspaces shiny. T2 disc punctures sparse (IS = 1-2.5 PD), interspaces shiny, apical impressed area impunctate, interspaces coriarious.

Structure. Face length/width ratio 0.87-0.88. F1: pedicel length ratio 1.27. F2:F1 length ratio 1.5. Gena narrower than eye. Hypostomal carinae parallel. Pronotal angle obtuse. Mesoscutum length/width ratio 0.82-0.85; mesoscutum/mesoscutellum length ratio 2.44; mesoscutellum/metanotum length ratio 1.78; metanotum/metapostnotum length ratio 0.77. Propodeum lateral carina nearly reaching dorsal margin; oblique carina absent. Tegula ovoid. Forewing with 3 submarginal cells. Metatibial spurs ciliate. Metasoma slender, parallel sided.

Etymology.

The specific epithet is derived from the name of the island. Saint Lucia is the only sovereign nation named after a historical woman.

Notes.

Males are associated with females in part by the shared head length consistent with patterns seen between L. dominicense and L. kilpatrickae in Dominica.

Figures

Figure 5. Lasioglossum (Dialictus) luciae sp. nov., paratype female A lateral habitus B dorsal habitus C head, frontal view D head, lateral view E tergum 1, dorsal view.

Figure 6. Lasioglossum (Dialictus) luciae sp. nov., holotype male A lateral habitus B dorsal habitus C head, frontal view D metasoma, dorsal view.

Figure 7. Lasioglossum (Dialictus) kilpatrickae Gibbs, 2016, male A dorsal habitus B head, frontal view C lateral habitus.