Lasioglossum (Habralictellus) eickwortellum ( Engel, 2001 )

Gibbs, Jason, 2018, Bees of the genus Lasioglossum (Hymenoptera: Halictidae) from Greater Puerto Rico, West Indies, European Journal of Taxonomy 400, pp. 1-57 : 40-43

Lasioglossum (Habralictellus) eickwortellum ( Engel, 2001)

Figs 4C , 24–26

Habralictellus eickwortellus Engel, 2001b: 35 (holotype, ♀, deposited at CUIC, examined).

Habralictellus eickwortellus – Moure 2007: 858 (catalogue).

Lasioglossum (Dialictus) eickwortellum – Genaro & Franz 2008: 6 (distribution); Lasioglossum (Habralictellus) eickwortellum – Gibbs 2016: 17 (taxonomy).

Etymology

Engel (2001b) named this species after Dr. George C. Eickwort.

Diagnosis

The female of L. eickwortellum is easily recognized by the bright blue-green to purple head and mesosoma, long face (length/width ratio>1.04) and metasoma with T1–T2 orange-red, T3–T6 brown with metallic reflections. The male of L. eickwortellum is similar to the female, but has more extensive testaceous colouration on the metasoma, as well as yellow/testaceous colour on the clypeal distal margin; mandible and all legs are entirely yellow. Both sexes have three submarginal cells and mesoscutum with distinctive dense punctures that are closely packed over the entire surface. It is easily distinguished from L. (Habralictellus) rufopanticis , which has a wide face, sparse mesoscutal punctures, typically two submarginal cells and different patterns of metasomal colour (usually all orange-red or all brown).

Material examined

PUERTO RICO: Ponce / Jayuya: ♀, holotype, Cerro de Punta , Toro Negro State Forest , Cordillera Central, s. d ., s. coll. ( CUIC). – Ponce: 1 ♀, Vasquez, sun, 18°07.4616′ N, 66°38.2638′ W, elevated bee bowl, 15 Jul.–12 Aug. 2014, S.G. Prado leg. ( NCSU). – Rio Grande: 1 ♂, submarginal cells 2/3, El Yunque, Rio Grande trail, 850 m a.s.l., resting on Hibiscus leaf, 2 Sep. 2007, J.E. Mercada leg. ( JAGC). – Yauco: 1 ♀, 1 ♂, Montana SH2, 18°08.188′ N, W 66°49.107′ W, Malaise trap, 20 Jun.–18 Jul. 2014, S.G. Prado leg. ( NCSU); 1 ♀, same collection data as preceding, 12 Sep.–10 Oct. 2014 ( NCSU); 1 ♀, Villa Cecilia, 18°08.371′ N, 66°49.230′ W, net (9:15–10:45 am), 4 Jun. 2014, S.G. Prado leg. ( NCSU).

Description

Male

MEASUREMENTS. Head length: 1.4 mm; head width: 1.3 mm; intertegular distance: 1.0 mm (n=1). Similar to female except for typical sex associated characters.

COLOURATION. Head and mesosoma bright metallic green with gold reflections, except as follows. Labrum yellow. Mandible yellow with red apex, dark brown basally. Clypeus distal half yellow. Antenna dark brown, anterior face of scape yellow, F9–F10 with ventral surface dark reddish brown. Tegula honey-coloured. Wing membrane hyaline, with dark setae, venation and pterostigma dark brown. Legs entirely yellow. Metasomal terga yellow, except apical impressed areas, T6–T7 entirely and T3–T4 lateral foveae brown.

PUBESCENCE. Dull white. Relatively sparse erect setae throughout. T6–T7 and S1–S4 with relatively long setae.

SURFACE SCULPTURE. Face tessellate-granular, punctation fine and relatively sparse throughout. Clypeus punctation sparse (i=1–2.5 pd), surface smooth distally (i =2–3 pd), supraclypeal area with punctures moderately sparse (i=1–2.5 pd), and lower paraocular area punctation dense (i= 1–1.5 pd). Upper paraocular area and frons denser (i=1 pd). Postgena lineolate. Mesoscutum densely, consistently punctate (i = pd), sparser anteriorly and medially (i=1–3 pd); mesoscutellum similarly punctured across surface. Mesopleuron and propodeum tessellate, with only obscure, sparse punctation. Metapostnotum with short irregular rugae-carinulae reaching halfway to posterior margin. Metasomal terga polished, punctation very fine and spaser (i= 1–4 pd), apical impressed areas impunctate. Metasomal sterna sparsely punctate subapically (i =2–4 pd).

STRUCTURE. Head slightly longer than wide (length/width ratio =1.04). Eyes weakly convergent below. Clypeus ½ below suborbital tangent. Gena narrower than eye. Hypostomal carinae subparallel. Ratio of pedicel, F1 and F2= 12:12:13; F2–F11 approximately 1.1× as long as wide. 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 4–5 branches, proximal branch as wide as base of rachis. Metapostnotum narrowly rounded onto posterior propodeal surface. Propodeum with lateral carina short, reaching halfway dorsal margin; oblique carina absent. T2–T4 impressed areas medially about 2/5 longitudinal length of basal area.

TERMINALIA. As illustrated in Fig. 4C . Gonostylus very broad, entirely covered in long setae; retrorse lobe absent.

Distribution

Puerto Rico (exclusively known from high elevation sites) ( Fig. 26 ).

Remarks

This species was described based on a single female specimen. Three additional females and two males have been examined. The male is described above for the first time. An unusual feature of the male is the pectinate inner metatibial spur, which appears similar to that of the female. This is unusual for males of Lasioglossum , although it is present in species formerly classified as the subgenus Sudila Cameron, 1898 ( Sakagami et al. 1996) (now included in Hemihalictus s. lat. (Gibbs et al. 2013)). Males of L. (Habralictellus) eleutherense ( Engel, 2001) from Half Moon Cay, Bahamas (FSCA) and L. (H.) rufopanticis ( Engel, 2001) from Mona Island also have pectinate inner metatibial spurs (contra Engel 2001b). This character supports uniting these species groups within L. (Habralictellus) — as does the unusual male genital capsule, which has unusually broad gonostyli and lacks a retrorse lobe ( Engel 2001b: figs 1–2). Males of L. sierramaestrense ( Genaro, 2001) have finely dentate inner metatibial spurs with shorter and more numerous teeth than the female spur. The holotype and paratype male of L. obamai Genaro, 2016 do not have toothed inner metatibial spurs and the genitalia look quite different from those of L. eickwortellum and L. rufopanticis , having slender elongate gonostyli and distinct retrose lobes ( Genaro 2016: fig. 16). The females of all known species of L. (Habralictellus) lack the T1 appressed fan, which is present in most North American members of L. ( Dialictus ), but not all species ( Gibbs 2009b, 2010b, 2011). The large size, bright metallic reflections, and absence of an appressed T1 fan of the adriani group species of L. (Habralictellus) is similar to the situation in some Neotropical species of Lasioglossum (J. Gibbs, unpublished data).

Two members of L. (Habralictellus) occurring in the Lesser Antilles, Lasioglossum auratum (Ashmead, 1900) and L. punctifrons (Crawford, 1914) , show close affinity to L. eickwortellum , particularly in the shape of the head and the presence of three submarginal cells ( Gibbs 2016). Both of these species lack the dense and distinct mesoscutal punctures and seem to have entirely dark metasoma.

Figures

Fig. 4. Line drawings of male genital capsules in ventral (left side) and dorsal (right side) views. A. L. amona sp. nov. B. L. dispersum sp. nov. C. L. eickwortellum (Engel, 2001). D. L. enatum sp. nov. E. L. genaroi sp. nov. F. L. gundlachii (Baker, 1906).

Fig. 24. Lasioglossum eickwortellum (Engel, 2001), ♀. A. Face. B. Lateral habitus. C. Dorsal habitus. Scale bars = 1 mm.

Fig. 25. Lasioglossum eickwortellum (Engel, 2001), ♂. A. Face. B. Lateral habitus. C. Dorsal habitus. Scale bars = 1 mm.

Fig. 26.Distribution mapfor Lasioglossum eickwortellum (Engel, 2001).