Colletes sexangulus Ferrari, 2019

Ferrari, Rafael R., 2019, A revision of Colletes Latreille (Hymenoptera: Colletidae: Colletinae) from Brazil, Paraguay and Uruguay, Zootaxa 4606 (1), pp. 1-91 : 76-78

Colletes sexangulus Ferrari , new species

( Figs. 33 , 44)

Diagnosis: The female C. sexangulus n. sp. (the male is unknown) can be diagnosed by the combination of labrum medially concave and margined laterally by longitudinal ridges, clypeal convex area obliquely striate, and mesoscutum covered with pale-orange hairs. Colletes sexangulus n. sp. is most similar to C. furfuraceus as in both the labrum is concave mid-longitudinally and concavity is marginal by lateral ridges, the mesoscutum is covered with pale-orange pubescence and the metasomal terga (except T6) with pale-yellow appressed hairs. However, these species can be differentiated by clypeus deeply and broadly (maximum breadth 1.8x MOD below) depressed midlongitudinally in C. sexangulus n. sp. (clypeus not depressed in C. furfuraceus ); hind basitarsus relatively long, ~ 4x MOD, in C. sexangulus n. sp. (hind basitarsus ~3.5x MOD in C. furfuraceus ); and T1–T5 with pale-yellow marginal zones in C. sexangulus n. sp. (T1–T5 marginal zones dark-brown in C. furfuraceus ).

Description: FEMALE ( Figs. 44 A–C):

Dimensions (mm): Approximate body length 9.8; head width 3.4; head length 2.7; intertegular distance 2.8; forewing length 7.9.

Colouration: Black except distal half on mandible, distal 3/5 of tarsal claws, S6 mid-longitudinally reddishbrown. Ventral surface of flagellum (except ventral surface of F2–F5 pale-brown), dorsal surface of distitarsi and hind tibia and basitarsus, S2 posteromedially, S3–S5 posteriorly dark-brown. Tegula, wing venation (except forewing veins R1, RS, 2r-m and 2m-cu of dark-brown and R black), stigma pale-orange. Tibial spurs, marginal zones of T1–T5 and S1–S6 pale-yellow. Proximal 2/5 of tarsal claws pale-brown.

Structure: Labrum medially concave; concavity margined laterally by longitudinal ridges. Clypeal mid-longitudinal area deeply and narrowly (0.6x) depressed above; depression slightly shallower and much broader (maximum width 1.8x MOD) below. Malar area 0.8x as long as basal depth of mandible (40:48). Hypostomal carina short and flat. F1 ~1.4x as long as its apical width (29:21). UID:LID (67:59). Frontal area without protrusion below lateral ocellus. Vertexal area concave behind upper summit of eye in postero-lateral view. Dorsolateral angle of pronotum pointed. Mesepisternum ventrally, near ventral end of episternal groove, without protrusion surrounded by appressed hairs. Horizontal surface of metapostnotum ~0.5x as long as metanotum (27:50); metapostnotal pits well-delimited; posterior transverse carina sinuous and complete. Posteromedial surface of front coxa without spine. Posterior hind tibial spur ciliate. Hind basitarsus ~4.1x longer than broad (58:14). Outer rami of hind tarsal claws 2x as long as inner rami (18:9). Marginal zone of T1 flat. Marginal zone of S6 depressed.

Pubescence: Head with off-white, plumose, erect, moderately long hairs; except mandible with fuscous setae; interantennal area with long hairs; paraocular and frontal areas with off-white and black hairs intermixed; vertexal area with black, long hairs; genal area with moderately short hairs above. Mesosoma with pale-orange, plumose, erect, moderately long hairs; those hairs longer on metanotum, longest on upper margin of lateral surface of propodeum; mesepisternum and metepisternum with pale-yellow, long hairs; disc of lateral surface of propodeum with appressed, short hairs. Legs with pale-yellow setae (except front tibia and basitarsus with fuscous setae); trochanters and femora with plumose, erect, long hairs; femoral and tibial scopae with branched apically only, suberect, very long hairs anteriorly; tibiae and basitarsi with erect, moderately long setae (except front tibia with suberect short setae anterodorsally and basitarsi with long setae on posterior margins). Metasomal terga covered with pale-yellow, plumose, appressed, short hairs (except T5–T6 with black, suberect, moderately short setae); T1 also with plumose, erect, very long hairs; T2–T4 also with pale-yellow, erect, short setae (those setae black and longer on T4). Metasomal sterna with pale-yellow hairs (except S6 with fuscous setae posteriorly); S1 with plumose, erect, moderately long hairs; S2–S6 discs with erect, moderately short setae (except S2 with plumose hairs posteromedially and S3 with short setae anteriorly); S2–S4 marginal zones with a transverse line of plumose, suberect hairs.

Surface sculpture: Clypeal mid-longitudinal depression moderately densely and finely punctate (interspaces rugulose); adjacent convex area densely and moderately coarsely punctate, punctures coalescent with striate interspaces. Supraclypeal area sparsely and moderately finely punctate on disc; interspaces imbricate. Malar area longitudinally sparsely and finely punctate; interspaces finely striate. Paraocular area densely and moderately finely punctate (except puncture fine towards antennal socket and near eye); interspaces smooth. Frontal area densely and moderately coarsely punctate; interspaces imbricate. Vertexal area punctures crowded and moderately fine near lateral ocellus; punctures sparser and finer towards eye; interspaces smooth throughout. Mesoscutum and scutellum densely and coarsely punctate; interspaces smooth. Metanotum punctures crowded and moderately fine. Mesepisternum densely and coarsely punctate (except punctures crowded anterior to episternal groove and moderately sparse ventrally); interspaces smooth. Metepisternum with oblique carinae mid-anteriorly; rugose above; imbricate below. Lateral surface of propodeum sparsely and finely punctate; interspaces smooth. Vertical surface of metapostnotum rugulose above. Metasomal terga with smooth interspaces; T1 finely and sparsely punctate; T2–T5 minutely punctate. Metasomal sterna with imbricate interspaces; S1 sparsely and finely punctate; S2–S3 moderately densely and finely punctate (except punctures sparse mid-longitudinally); S4–S5 densely and finely punctate; S6 densely and moderately finely punctate (except punctures sparse mid-longitudinally).

MALE: Unknown.

Type material: Holotype ♀ —“RPSP; 12.4157”. “ Brasil, RS, Rd. BR 153; 39 km NE Bagé , 30º52’15’’S; 53º36’59’’W em Fabaceae ; 01.xi.2012 E.Almeida & A.Aguiar ”. “VOUCHR # 08; Pampas-RS 2012”. “CCDB- 24581 A11”. “ HOLOTYPE; Colletes sexangulus ♀; Ferrari, new species”. { RPSP}.

Paratype: BRAZIL — Rio Grande do Sul: Santana da Boa Vista, Guaritas , 13/xi/1992, [C. Schlindwein], 1♀, { UFMG }.

Range: BRAZIL (Rio Grande do Sul). See also Fig. 33 .

Biogeographical distribution: Chacoan dominion (Pampean province) at altitudes of 0–400m a.s.l.

DNA barcode: Unavailable.

Floral hosts: Unknown.

Etymology: Allusion to its characteristic hexagonal clypeus.

Comments: Apparently a rare species that might be endemic to the Pampas ecoregion in the South American southeast.

Figures

FIGURE 33. Geographical distribution of Colletes ornatus (blue circles), and C. sexangulus n. sp. (red stars). Scale bar ap- proximately 250km.

FIGURE 44. Colletes sexangulus n. sp. Female: (A) habitus, dorsal view (B); face, frontal view; (C) habitus, lateral view. Scale bars = 1mm.