Lasioglossum (Dialictus) monense, Gibbs, 2018

Gibbs, Jason, 2018, Bees of the genus Lasioglossum (Hymenoptera: Halictidae) from Greater Puerto Rico, West Indies, European Journal of Taxonomy 400, pp. 1-57 : 23-27

Lasioglossum (Dialictus) monense sp. nov.

urn:lsid:zoobank.org:act:7 F94073 B-DCB1-49A4-9956-DE505ACA07C3

Figs 12–14

Diagnosis

Both sexes of L. monense sp. nov. can be recognized by the following: tegula punctate and extended posteriorly to form small angle, mesepisternum punctate and metasoma reddish brown to brown. The shape of the tegula distinguishes it from all other species of L. ( Dialictus ) from Puerto Rico, except L. enatum sp nov. Other members of the L. parvum species complex, to which it belongs, share this character. Females differ from L. enatum sp. nov. by the more obscure supraclypeal punctures, finer mesoscutal punctation with more densely tessellate interpsaces, smooth dorsolateral slopes, and brownish red metasomal terga. The male has the mesoscutum and mesepisternum duller than in L. enatum sp. nov. due to microsculpture. In the female, the complete absence of punctures on the apical impressed margins distinguishes L. monense sp. nov. from L. parvum and L. busckiellum , which both have minute setose punctures in this area. In the male, the appressed sternal setae and dark tarsi distinguish L. monense sp. nov. from L. parvum , which has sternal setae erect and tarsi pale.

Etymology

The specific epithet monense is a Latin adjective meaning “from Mona”.

Material examined

Holotype PUERTO RICO: ♀, Mona Island, near Playa Pájaros , 30 m a.s.l., general collecting, 18°03ʹ52ʺ N, 67°52ʹ06ʺ W, N. Franz leg. ( NMNH). [Original label: Mona Island (PR USA), near Playa Pàjaros, 30 m, general collecting, 18°03ʹ52ʺ N, 67°52ʹ06ʺ W, leg. N. Franz, V-18-2008 // HOLOTYPE Lasioglossum (Dialictus) monense .]

Paratypes PUERTO RICO: Mona Island: 1 ♀, topotypical ( JBWM) ; 1 ♀, Mona Island, 13–16 Nov. 2000, J.A. Genaro and M.A. Garcia leg. ( JBWM) ; 1 ♂, Mona Island, Punta Caigo o no Caigo , 22 Nov. 2007, J.A. Genaro leg. ( JBWM) ; 1 ♂, Ulvero, road above , 11 Nov. 1992, Snelling and Torres leg. ( LACM).

Description

Female

MEASUREMENTS. Head length: 1.28–1.33 mm (x = 1.31 mm, n= 3); head width: 1.36–1.38 mm (x= 1.36 mm, n =3); intertegular distance: 0.94 (x = 0.94 mm, n=3).

COLOURATION. Head and mesosoma dull metallic golden green, except as follows. Labrum and mandible reddish brown. Clypeus distal-half dark brown. Supraclypeal area bronze. Antenna dark brown, F2–F10 with ventral surface reddish brown. Tegula dark honey-coloured. Wing membrane hyaline with dark setae, venation and pterostigma brown. Legs dark brown, tarsi reddish brown, metabasitarsus mostly brown. Metasomal terga brownish red, basal areas darker.

PUBESCENCE. Dull white. Relatively sparse erect setae throughout, without tomentum, except sparse basolateral patches of T2–T3 and basally on T4. T1 with complete fan of appressed setae on anterior surface. T2–T4 without apical fimbriae medially, T3–T4 with sparse fine setae on apical impressed areas, sparse fimbriae laterally. Scopa well developed on hind leg and metasomal sterna.

SURFACE SCULPTURE. Face imbricate, punctation fine, finer on frons, coarse on distal clypeus. Clypeus punctation sparse (i =1–2.5 pd), finer and denser proximally, surface smooth distally (i= 2–3 pd), supraclypeal area with punctures moderately sparse (i =1–2.5 pd), indistinct among sculptured interspaces and lower paraocular area punctation dense (i≤ pd). Upper paraocular area and frons finely reticulatepunctate (i<0.5 pd). Ocellocular area densely punctate (i≤ pd). Gena lineolate and postgena imbricate. Mesoscutum tessellate, punctation fine, dense on lateral and posterior portions (i =1–1.5 pd), slightly sparser anteriorly and medially; mesoscutellum similar, evenly punctured across surface. Metanotum imbricate-punctate. Preëpisternum punctate-reticulate. Hypoepimeral area finely, densely reticulatepunctate (i<0.5 pd). Mesepisternum below scrobe densely punctate (i≤ pd), interspaces imbricate, but shining below. Metepisternum dorsal ⅓ rugoso-carinulate, ventral portion imbricate. Metapostnotum with irregular rugae-carinulae often reaching to posterior margin, carinulae not extending to dorsolateral slope. Propodeum posterior surfaces polished tessellate, distinct punctures on lateral surface (i=3–5 pd). Metasomal terga polished, finely coriarious on T1 anterior surface and apical impressed areas; punctation very fine (i=1–2 pd), apical impressed areas impunctate. Metasomal sterna coriarious and finely, sparsely punctate (i= 2–4 pd).

STRUCTURE. Head slightly wider than long (length/width ratio= 0.93–0.98). Eyes weakly convergent below. Clypeus 3/5 below suborbital tangent. Gena narrower than eye. Hypostomal carinae subparallel. Pronotal dorsolateral angle obtuse. Pronotal ridge rounded, interrupted by sulcus. Tegula long, extended posteriorly into medially directed projection. 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 nearly reaching dorsal margin; oblique carina very fine. T2–T4 impressed areas medially about 2/5 longitudinal length of basal area.

Male

MEASUREMENTS. Head length: 1.08–1.23 mm (x = 1.16 mm, n= 2); head width: 1.07–1.21 mm (x= 1.14 mm, n =2); intertegular distance: 0.63–0.76 mm (x = 0.70 mm, n=2).

Similar to female except for typical sex associated characters and as follows.

COLOURATION. Head and mesosoma dull metallic golden green. Ventral surface of F1–F11 brownish yellow. Tarsi brownish red. Metasomal terga dark brown.

PUBESCENCE. Lower paraocular area and clypeus with subappressed tomentum, partially obscuring surface. Metasomal terga without tomentum. Metasomal sterna with sparse, posteriorly directed setae.

SURFACE SCULPTURE. Clypeus punctures dense (i<pd), evenly sized. Preëpisternum reticulate-punctate. Mesepisternum dull due to microsculpture; punctate. Propodeum lateral surface densely punctate (i <pd); dorsolateral slopes smooth tessellate. Metasomal terga with apical impressed areas impunctate.

STRUCTURE. Head about as long as wide (length/width ratio =1.01–1.02). Eyes convergent below. Ratio of pedicel, F1 and F2 =11:12:17; F2–F11 approximately 1.3–1.4× as long as wide. Metasomal terga with apical impressed areas medially less than ⅓ length of basal area. T2–T3 depressed anteriorly.

TERMINALIA. Similar to as illustrated in Fig. 4 .

Distribution

This species is apparently endemic to Mona Island ( Fig. 14 ).

Biology

Lasioglossum monense sp. nov. visits Mammillaria nivosa Link ex Pfeiff. (Cactaceae) .

Remarks

Lasioglossum monense sp. nov. could be considered a subspecies of L. enatum sp. nov., although use of this category can be controversial ( Zink et al. 2016). The differences in microsculpture are similar to species-level differences, but it seems probable that these two species share a very recent ancestor. No specimens that could be attributable to either species have been seen from Hispaniola.

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. 12. Lasioglossum monense sp. nov.,♀. A. Face. B. Lateral habitus.C. Dorsal habitus.Scale bars = 1 mm.

Fig. 13. Lasioglossum monense sp. nov.,♂. A. Face. B. Lateral habitus.C. Dorsal habitus.Scale bars = 1 mm.

Fig. 14. Distribution mapfor Lasioglossum monense sp. nov. in Puerto Rico.