Lasioglossum (Dialictus) dominicense, Gibbs, 2016

Gibbs, Jason, 2016, Bees of the family Halictidae Thomson, 1869 from Dominica, Lesser Antilles (Hymenoptera: Apoidea), European Journal of Taxonomy 180, pp. 1-50 : 6-11

Lasioglossum (Dialictus) dominicense sp. nov.

urn:lsid:zoobank.org:act:95421366-50BE-49F3-B51C-91B51E7A0A90

Figs 2 A–C, 3A–C, 4A–B

Diagnosis

Lasioglossum dominicense sp. nov. females have the following characteristics: head wider than long (length/width ratio = 0.9; Fig. 2A ); mesoscutal and mesepisternal punctures distinct ( Fig. 2 B–C); mesoscutal setae entirely pale; submarginal cells three; and T1 appressed setal fan complete. The male is similar but lacks a T1 fan. Lasioglossum kilpatrickae sp. nov. is larger, with a distinctly longer head in both sexes (length/width ratio = 1.0; Figs 5A , 6A ). Lasioglossum kalinago sp. nov. is larger in size, with less distinct punctures on the mesepisternum and dark setae intermingled with pale setae on the mesoscutum. Lasioglossum punctifrons has a longer head, granular microsculpture with indistinct punctation, and lacks a complete T1 appressed setal fan. Lasioglossum roseauense sp. nov. has only two submarginal cells.

Etymology

The specific epithet refers to the collection locality in the Commonwealth of Dominica.

Type material

Holotype

DOMINICA: ♀, ATR[E] C Springfield, Mt. Joy trail, ‘site 3’, 15°21’ N, 61°22’ W, 424 m, 25 May–4 Jun. 2003, coll. T. Decker & W. Wells, Malaise trap, voucher # 645 ( TAMUIC).

Paratypes

DOMINICA: 3 ♀♀, St. Paul Parish, “Parish of St. Joseph” [sic], Springfield Estate, 15.34667° N, 61.3683° W, 430 m, 15–20 Mar. 2003, coll. M.E. Irwin & M. Shepard, Malaise trap ( BBSL); 1 ♀, ATR[E]C Springfield, Checkhall River, ‘site 4’, 15°21’ N, 61°22’ W, 294 m, 24 May–4 Jun. 2003, coll. T. Decker & W. Wells, Malaise trap, voucher # 645 ( TAMUIC); 2 ♀♀, ATREC, Springfield, 345 m, 15.34656° N, 61.36901° W, 31 May 2014, coll. S.K. Kilpatrick, pan traps ( TAMUIC); 1 ♀, ATREC, Springfield, 345 m, 15.34656° N, 61.36901° W, 3 Jun. 2014, coll. S.K. Kilpatrick, pan traps ( TAMUIC); 8 ♀♀, ATREC, Springfield, 345 m, 15.34656° N, 61.36901° W, 5 Jun. 2014, coll. S.K. Kilpatrick, pan traps ( TAMUIC); 2 ♀♀, ATREC, Springfield, 345 m, 15.34656° N, 61.36901° W, 6 Jun. 2014, coll. S.K. Kilpatrick, pan traps ( TAMUIC); 5 ♀♀, 1 Ƌ, ATREC, Springfield, 345 m, 15.34656° N, 61.36901° W, 7–8 Jun. 2014, coll. S.K. Kilpatrick, pan traps ( TAMUIC); 3 ♀♀, Springfield, Nov. 1967, coll. N.L.H. Krauss ( NMNH); 1 ♀, St. George Parish, Long Ditton, 20 Jun. 1911 ( AMNH); 2 ƋƋ, Roseau, 0–100 m, Jul. 1976, coll. N.L.H. Krauss ( NMNH).

Description

Female

MEASUREMENTS (n = 8). Length 3.5–3.8 mm (mean = 3.6); head length 1.1–1.2 mm (mean = 1.1); head width 1.2–1.3 mm (mean = 1.2); intertegular distance 0.8–1.0 mm (mean = 0.9).

COLOURATION. Head and mesosoma dull metallic golden-green, except as follows. Labrum brown. Mandible brown with red apex. Clypeus distal half dark brown. Supraclypeal area bronze. Antenna dark brown, flagellum with ventral surface dark reddish brown. Tegula dark reddish brown. Wing membrane hyaline with dark setae, venation and pterostigma brown. Legs dark brown, except medio- and distitarsi and portions of metabasitarsus reddish brown. Metasomal terga blackish brown, reddish brown apically.

PUBESCENCE. Dull white. Relatively sparse erect setae throughout, without tomentum, except on gena near eye, pronotum dorsolateral angles and lobe, narrow basolateral patches of T2–T3 and sparsely on T4. Metasomal T1 with complete fan of appressed setae on anterior surface. T2 without apical fimbriae, T3–T4 with only sparse, fine setae on apical impressed areas. Scopa well developed on hind leg and metasomal sterna.

SURFACE SCULPTURE. Face imbricate, punctation moderately fine. Clypeus punctation sparse (i = 1–2.5 pd), denser proximally, surface smooth distally (i = 2–3 pd). Supraclypeal area with punctures sparse, present medially (i = 1–2 pd), and lower paraocular area punctation dense (i ± pd). Upper paraocular area and frons reticulate-punctate (1 <pd). Ocellocular area punctate (i ± pd). Gena and postgena polished, finely punctate-lineolate. Mesoscutum imbricate, punctation moderately fine, dense on laterad of parapsidal lines, posterior portion (1 <pd), sparser medially (i = 1–2 pd); mesoscutellum similar, with small submedial impunctate area (i = 1–2 pd). Metanotum imbricate. Preëpisternum finely reticulate rugulose. Hypoepimeral area finely punctate. Mesepisternum below scrobe punctate (1 <pd), finely imbricate. Metepisternum dorsal ¼ rugulose, ventral portion imbricate. Metapostnotum medially with irregular rugae reaching ¾ distance to posterior margin, oblique carinulae on lateral portions extending to dorsolateral slope. Propodeum posterior and lateral surfaces polished tessellate. Metasomal terga polished, finely coriarious on apical impressed areas, T1 anterior face polished; punctation fine, obscure on basal portions (i = 1–2 pd), indistinct, sparser on apical impressed areas. Metasomal sterna coriarious and finely, sparsely punctate (i = 2–4 pd).

STRUCTURE. Head round (length/width ratio = 0.9). Eyes weakly convergent below. Clypeus ½ below suborbital tangent. Gena narrower than eye. Hypostomal carinae subparallel. Pronotal dorsolateral angle obtuse. Pronotal ridge rounded, interrupted by sulcus. Tegula ovoid. Submarginal cells three (1rs-m present). Distal hamuli arranged 2-1-2. Inner metatibial spur pectinate, with 3–4 branches, proximal branch much longer than width of rachis. Metapostnotum narrowly rounded onto posterior propodeal surface. Propodeum with lateral carina reaching ¾ distance to dorsal margin; oblique carina fine. T2–T4 impressed areas medially about ½ longitudinal length of basal area.

Male

MEASUREMENTS (n = 1). Length 4.4 mm; head length 1.2 mm; head width 1.2 mm; intertegular distance 0.8 mm.

COLOURATION. Similar to female, except tarsi reddish.

PUBESCENCE. Similar to female, except scopa absent. Lower paraocular area with sparse tomentum. T1 fan absent. T2–T4 without evident tomentum.

SURFACE SCULPTURE. Similar to female, but more polished, with less evident imbricate microsculpture. Metanotum sparsely punctate (i = 1–1.5 pd) Metepisternum punctate. Lateral surface of propodeum distinctly punctate. T1–T4 apical impressed areas impunctate.

STRUCTURE. Similar to female, with typical sexual differences. Head round (length/width ratio = 0.97). F2 length nearly 2 × F1. Scape, pedicel and F1 reaching lower margin of median ocellus. Antenna reaching posterior margin of mesosoma. T2–T4 apical impressed areas less than ¼ of median length.

TERMINALIA. As shown in Fig. 4 A–B.

Remarks

Lasioglossum dominicense sp. nov. bears some superficial resemblance to members of the L. parvum species group in its size and overall appearance, but it lacks the enlarged tegula diagnostic for that complex. It is perhaps most similar to L. sanctivincenti , and could easily be considered a subspecies based on the close similarity to that species. Lasioglossum sanctivincenti appears to have more distinct microsculpture throughout, which is most apparent in the interspaces of the mesoscutum and the anterior face of T1. The puncture density mesad of the parapsidal line is slightly denser (1 <pd) and more numerous to a distance of about 3–4 puncture diameters from the parapsidal line. If the species were sympatric it would be challenging to differentiate them and any variation in the above characters would make distinguishing them next to impossible. A more comprehensive survey of the intervening islands would be useful for clarifying the biogeographic history of these and other species in the Lesser Antilles.

Figures

Fig. 2. Lasioglossum (Dialictus) dominicense sp. nov. Holotype (A, C) and paratype (B), ♀♀. A. Face. B. Lateral habitus. C. Dorsum of mesosoma. Scale bars = 1 mm.

Fig. 5. Lasioglossum (Dialictus) kilpatrickae sp. nov. Holotype, ♀. A. Face. B. Lateral habitus. C. Dorsum of mesosoma. Scale bars = 1 mm.

Fig. 6. Lasioglossum (Dialictus) kilpatrickae sp. nov. Paratypes, ƋƋ. A. Face. B. Lateral habitus. C. Dorsum of mesosoma. Scale bars = 1 mm.

Fig. 4. — Genital capsule of Lasioglossum (Dialictus) dominicense sp. nov. Paratype, Ƌ. A. Dorsal view. B. Ventral view. — Genital capsule of Lasioglossum (Dialictus) kilpatrickae sp. nov. Paratype, Ƌ. C. Dorsal view. D. Ventral view. Scale bars = 1 mm.