Colletes nigritulus Friese, 1910

Ferrari, Rafael R., 2017, Taxonomic revision of the species of Colletes Latreille, 1802 (Hymenoptera: Colletidae: Colletinae) found in Chile, Zootaxa 4364 (1), pp. 1-137 : 90-94

Colletes nigritulus Friese, 1910

( Figs. 47A–F )

Colletes nigritulus Friese, 1910: 645, 1912: 366 ; Jaffuel & Pirion 1926: 364; Ruiz 1944: 216; Toro 1986: 123, 1999: 30; Moure & Urban 2002: 15; Moure et al. 2007: 685; Montalva & Ruz 2010: 22; Ascher & Pickering 2017. Syntype ♂ (examined). {ZMB}.

Colletes nigritula (sic); Moure 1956: 210.

Diagnosis. Colletes nigritulus is distinct among all Colletes known to occur in Chile as it is the only black species with a very short malar area, which is approximately 0.4/0.8x (♀/♂) as long as the basal depth of mandible (in all other black species ( C. alocochila , C. nigropilosus n. sp., C. mastochila ), the malar area is, at least, 1.0/1.5x as long as the basal depth of mandible).

Redescription. FEMALE ( Figs. 47A, 47C, 47E ): Dimensions (mm): Approximate body length 8.4–9.4; head width 3.2–3.5; head length 2.5–2.7; intertegular distance 2.6–3.0; forewing length 7.0–7.7.

Colouration: Black except dark-brown on tegula, wing veins (except veins R and C of forewing black), tibial spurs, distitarsi. Reddish-brown on distal half of tarsal claws; marked on distal 1/3 of mandible. Pale-brown on distal 1/5 of ventral surface of mid femur, proximal half of tarsal claws, marginal zones of metasomal sterna.

Structure: Labrum medially concave; concavity margined by lateral ridges. Clypeal mid-longitudinal area evenly shallowly and broadly (1.1x MOD) depressed; adjacent lateral area convex; apicomedial ridge absent.

Malar area ~0.4x as long as basal depth of mandible (23:52). F1 ~1.3x as long as its apical width (28:22). UID:LID (68:64). Genal area flat behind upper summit of compound eyes in lateral view. Dorsolateral angle of pronotum triangular acute. Horizontal surface of metapostnotum ~0.2x as long as metanotum (12:62); metapostnotal pits poorly-delimited; posterior transverse carina straight and interrupted medially. Posteromedial surface of front coxa without spine. Posterior hind tibial spur ciliate. Hind basitarsus ~ 4x longer than broad (51:13). Outer rami of hind tarsal claws ~1.8x as long as inner rami (22:12). Posterolateral area of S6 flat and lacking carina; marginal zone depressed.

Pubescence: Mixed off-white and black, plumose, erect, moderately long on lateral slopes of clypeus and supraclypeal area, paraocular, interantennal, frontal and vertexal areas, pronotal lobe, mesoscutum; such hairs long on metanotum, mesepisternum, metepisternum; entirely black on metanotum (except long), ventral surface of coxae, posteroventral surface of trochanters and front femur, ventral margin of mid femur, S1. Black, erect, moderately long setae on genal area (except plumose near proboscidial fossa and short behind upper summit of eye), dorsal surface of mid and hind basitarsi and tibiae (except moderately short on mid tibia); such hairs long on posterior surface of front tibia and basitarsus; very long on posterior margin of mid and hind basitarsi. Fulvous, erect, moderately long setae on mandible. Black, suberect, very long hairs, which are branched only apically on anterior surface of hind femur and tibia. Fulvous, suberect, moderately short, thick setae on ventral surface of mid and hind tarsi; thickest towards distal margin. T1–T3 with black, erect, short setae; moderately short on T4–T5. S2–S6 with minute, suberect setae on discs; erect, moderately short near marginal zone.

Surface sculpture: Clypeal mid-longitudinal depression densely and moderately sparsely punctate (interspaces rugulose); adjacent convex area more coarsely punctate; lower half striate. Malar area finely punctate near eye (interspaces imbricate); impunctate and smooth near mandible. Supraclypeal area imbricate. Paraocular area punctures crowded and coarse below; moderately coarsely and densely punctate above; interspaces smooth and shiny throughout. Frontal area coarsely and densely punctate; interspaces rugulose. Vertexal area rugose near lateral ocellus; sparsely and moderately finely punctate elsewhere. Mesoscutum and scutellum densely and moderately coarsely punctate (except sparsely punctate on mesoscutal mid-posterior area and scutellar midlongitudinal band); interspaces smooth and shiny (except rugulose on scutellar posterior 1/5). Metanotum densely and moderately finely punctate; interspaces rugose. Mesepisternum punctures crowded and coarse on upper 1/3 (interspaces smooth); moderately coarse and moderately sparse below (interspaces imbricate). Metepisternum rugose above; obliquely striate medially; smooth below. Punctation on lateral surface of propodeum difficult to discern from the overall rugulose interspaces. Upper area vertical surface of metapostnotum smooth medially. Metasomal terga minutely punctate; interspaces smooth on T1, imbricate on T2–T5, shiny throughout. Metasomal sterna densely and finely punctate (except moderately coarsely punctate on distal half of S6); interspaces imbricate.

MALE ( Figs. 47B, 47D, 47F ). As in female, except for usual secondary sexual characteristics and as follows:

Dimensions (mm): Approximate body length 8.4–9.3; head width 2.7–3.1; head length 2.1–2.4; intertegular distance 2.5–2.9; forewing length 6.2–6.9.

Colouration: Vein C of forewing, mediotarsi and discs of S2–S4 dark-brown. Stigma and distal 1/3 of distitarsi pale-brown.

Structure: Labrum medially convex; convexity not margined by ridges. Clypeal mid-longitudinal area narrowly (0.5x MOD) depressed on upper half; depression broad (=MOD) below. Malar area ~0.8x as long as basal depth of mandible (27:32). F1 ~0.9x as long as its apical width (23:26). UID:LID (65:52). Genal area concave behind upper summit of compound eyes in lateral view. Horizontal surface of metapostnotum ~0.2x as long as metanotum (11:54); metapostnotal pits well-delimited. Hind basitarsus ~4.2x longer than broad (55:13). Outer rami of hind tarsal claws ~2.1x as long as inner rami (17:8). Marginal zone of S6 not depressed. S7, S8 and genital capsule as in Figs. 48A, 48B, 48C , respectively.

Pubescence: Hairs on lateral slopes of clypeus and supraclypeal area mostly off-white. Genal area, T1, disc of T2 with plumose hairs. Setae on T3 moderately short. Plumose hairs on S1 off-white.

Surface sculpture: Clypeal and supraclypeal area with smooth interspaces. Scutellum moderately densely punctate. Mesepisternal punctation moderately coarse throughout. Metasomal terga finely punctate; interspaces smooth throughout. Metasomal sterna minutely punctate.

Material studied. Primary type specimen: Syntype ♂ —“ CHILE; CONCEPC .; X 1903; P. HERBST ”. “ Colletes ; nigritulus ; 1909 Friese det.”. “Typus”. “LECTOTYPE; Colletes nigritulus ; Friese, 1910; desig. Melo, 2015”. “http://coll.mfn-berlin.de/u/; 58f9be ”. { ZMB}.

Additional specimens: ARGENTINA—Chubut: INTA Trevelin , (-43.114, -71.590) , 688m, 17/i/2006, [A.Gravel], 1♀ 2♂♂, { PCYU}. CHILE — Region IV: E of Aduanas , (-30.138, -70.061) , 2706m, 3/ii/2016, [L.Packer], 2♂♂, { PCYU}. Region V: E of Río Blanco , (-32.878, -70.208) , 1898m, 30/xii/2008, [L.Packer], 1♂, { PCYU}. El Canelo , (-33.575, -70.445) , 865m, xi/1979, [L.Peña], 1♀, { AMNH}; idem, except i/1977, 1♂. Río Blanco, 31/i/1968, [ Montenegro], 1♂, { PUCV}. Region Metropolitana: Alhué , (-34.027, -71.099) , 180m, 17/xii/ 1987, [L.Peña], 1♂, { PCYU}. Region VII: Linares , (-35.847, -71.606) , 158m, i/1979, [L.Peña], 1♀, { AMNH}. Tregualemu , (-35.946, -72.739) , 55m, 28/xii/2006, [L.Packer], 1♂, { PCYU}; idem, except 17/xii/2006, 1♀. Vado Estero los Molongos , (-35.011, -70.743) , 779m, 26/i/2016, [L.Packer], 2♂♂, { PCYU}. Vilches , (-35.570, -71.178) , 587m, i/1999, [P.Arce], 1♂, { AMNH}. Region VIII: 14km W of Santa Juana , (-37.162, -73.106) , 619m, 2/xii/ 1997, [L.Packer], 3♂♂, { PCYU}. W of Parque Nacional Laguna del Laja , (-37.395, -71.457) , 921m, 3/iii/2013, [Postlethwaite & Monckton], 1♀, { PCYU}. Region IX: Chacamo , (-38.583, -73.053) , 414m, 19/i/1983, [L.Peña], 1♀, { AMNH}. Laguna Galletué , (-38.694, -71.286) , 1163m, 10/i/1962, [L.Peña], 1♂, { AMNH}. Victoria , (- 38.232, -72.351) , 348m, i/1985, [L.Peña], 1♂, {AMNH}.

Range. Argentina (Chubut), Chile (Regions IV–IX). See also Fig. 46B .

Biogeographic distribution. Central Chilean sub-region: (Coquimban and Santiagan provinces). Subantarctic region (Maule province). Patagonian sub-region (Patagonian province). Central Chilean and western Argentinean species distributed at altitudes of 0–2800m a.s.l.

DNA barcode. Available . BOLD: AAV9330 (4♀♀ 2♂♂). Barcoded specimens cover most of the latitudinal range of the species; representatives from central Chile and southern Argentina were assigned the same BIN. Distance from the nearest neighbour ( C. flavipilosus n. sp.): 5.28–6.03%.

Floral hosts. Escalloniaceae— Escallonia pulverulenta (Ruiz & Pav.) Pers. [ Jaffuel & Pirion 1926 (as E. berteroana DC.)]; E. virgata (Ruiz & Pav.) Pers. (this study). Quillajaceae— Quillaja saponaria Molina ( Ruiz 1944) .

Comments. Uncommon species although widely distributed in central Chile. Also found in southern Argentina.

The syntype male from the ZMB that I examined has been labelled as the species’ lectotype and should be designated as such in a different study (G. Melo, pers. comm.).

Figures

FIGURE 47. Colletes nigritulus Friese, 1910. Female: (A) habitus, lateral view; (C) face, frontal view; (E) habitus, dorsal view.Male:(B) habitus, lateral view; (D) face, frontalview; (F) habitus, dorsal view.Scale bars = 2mm.

FIGURE 48.Dorsal view of the male terminalia of C. nigritulus. (A) S7; (B) S8; (C) genital capsule.Scale bars = 1mm.

FIGURE46.Geographic distribution by Colletes species.(A) C.nigropilosus n. sp. and C.musculus; (B) C.ventricarinatusn. sp., C. quelu and C. nigritulus; (C) C.simulatus n. sp., C. sulcatus and C. toroi n. sp. Scale bars approximately 300 km.