Trichothurgus bolitophilus Durante & Roig Alsina, 2012

Sarzetti, Laura C., Genise, Jorge F. & Sanchez, M. Victoria, 2012, Trichothurgus bolithophilus sp. n. (Hymenoptera, Megachilidae) a bee nesting in horse manure pads in Patagonia, Argentina, Journal of Hymenoptera Research 29, pp. 1-14 : 6-8

Trichothurgus bolitophilus Durante & Roig Alsina sp. n. Figs 20 24

Description.

Female holotype. Body length 13.6 mm (paratypes, 13.0-16.0 mm), length of forewing 9.2 mm, maximum width of head 5.9 mm, maximum length of head 4.5 mm. Coloration.Integument black except under surface of flagellum and tibial spurs dark bseriesn; front tibial spur and claws dark ferruginous (later black api cally). Wings evenly weakly infuscate, with apex appearing darker, due to black papillae; veins and pterostigma blackish.

Pubescence. Black, with yellowish hairs as follows: on vertex, between ocelli, dorsal portion of pronotum including pronotal lobe, scutum, scutellum, axilae and metanotum. Hairs on T1-T4 black at sides and dark brown medially, on T2-T5 forming black apical bands; T6 with dense covering of coarse, black hairs. Scopa black.

Punctation.Integument generally coriaceous, except smooth and shiny on labrum, clypeus, mandible, supraclypeal area below protuberance, around lateral ocellus, malar area, and on center of scutum. Clypeus with punctation sparse and irregular on basal medial area; punctures becoming smaller and denser toward apical and lateral margins. Supraclypeal area with few, scattered punctures below protuberance. Rest of head with small and dense punctures, except around ocelli. Mandibles unpunctured except on outer interspace. Scutum on mid-posterior region with large punctures separated by 0.3-1 times their diameter; punctures becoming smaller and denser on rest of surface; anteriorly with dense, poorly defined punctures. Scutellum and axilla with punctures separated basally, and denser toward posterior margin. Metapostnotum microsculptured. T1 with sparse, shallow punctures apically, separated by twice their diameter; punctures on T2-T5 becoming denser toward apex of metasoma.

Structure. Inner margins of eyes straight, subparallel, slightly divergent below (upper to lower interocular distance 0.97; paratypes 0.95-1.01); paraocular carina present. Lengths of scape, 1.20; pedicel, 0.24; flagellomeres 1 to 3, 0.42: 0.22: 0.22; flagellomere 10, 0.30; first flagellomere shorter than combined lengths of flagellomeres 2+3. Interantennal distance longer than distance from antennal insertion to median ocellus (1.10-0.50), shorter than antennocular distance (1.10-1.35), and subequall to antennoclypeal distance (1.10-1.00). Labrum 1.07 times as long as basal width (paratypes 1.03-1.35); base of labrum with median longitudinal keel (0.11 times length of labrum; variable in paratypes, 0.08-0.28, Fig. 23, k ) short paramedian carina ( Fig. 23, p ) and strong lateral carina ( Fig. 23, l ); median keel continued apically by deep longitudinal furseries ( Fig. 23, f ) reaching preapical constriction ( Fig. 23, c ) (width of furseries 0.60 times median ocellar diameter; paratypes 0.74-0.88); median part of labrum broadened, with convex lateral margins (maximum width of median part 3.7 times median ocellar diameter; paratypes, 3.57-3.94); apex beyond constriction laterally pointed, and apically rounded to weakly pointed (some paratypes) (constriction as wide as median ocellar diameter; paratypes, 0.79-1.11). Clypeus flat, 0.73 times as long as basal width (paratypes 0.62-0.68); apical margin medially straight ( Fig. 22 ). Supraclypeal area with facial protuberance prominent, convex in dorsal view, not carinate, laterally with conical projections (these projections are more developed in larger specimens) ( Figs 21-22 ). Median ocellus located below supraorbital line; proportion of interocellar distance to ocellocular distance 0.64 (paratypes, 0.54-0.55); proportion of interocellar distance to ocelloccipital distance, 0.54 (paratypes, 0.46-0.50). Gena broader than eye in lateral view (1.17; paratypes, 1.25-2.66).

Observations.

This species is closely related to Trichothurgus laticeps (Friese) and Trichothurgus dubius (Sichel) by the shape of the labrum, with a preapical constriction, and th e similar shape of the facial prominence, with short lateral conical projections. It is intermediate in the color pattern of the vestiture, being Trichothurgus laticeps entirely black, and Trichothurgus dubius extensively white. The base of the labrum and the shape of the apical portion are different in the three species. The apex beyond the constriction is rounded in Trichothurgus laticeps and Trichothurgus dubius , without lateral conical projections. The base of the labrum in Trichothurgus dubius bears a bifid projection, while in Trichothurgus laticeps it bears a spiniform projection and several rugae between the median keel and the paramedian carinae.

A single male with the same labels as the female from Patagonia, San Jorge, is tentatively associated. Diagnostic structures of the labrum and the face in Trichothurgus are different in females and males, making sex association very difficult. This male has a similar color pattern, except that it bears white hairs on the face and on the first tergum. It completely lacks a facial protuberance, being the supraclypeal area slightly convex. Both the supraclypeal area and the clypeus are densely micropunctate, with the punctures coalescent, giving a dull appearance ( Fig. 24 ). The labrum has a basal transverse depression delimited by a carina, the apex is rounded, and the median longitudinal depression is shallow ( Fig. 24 ). The base of the labrum in Trichothurgus laticeps and Trichothurgus dubius is depressed laterally only, bearing medially a rounded protuberance which is not carinate apically. Males of Trichothurgus laticeps are further differentiated by the sparser punctures with shiny interspaces on the clypeus and supraclypeal area.

Etymology.

The name refers to the habits of this species, which makes its nests in dung pads (boliton, greek).

Distribution.

Argentina, provinces of Santa Cruz, Chubut and Mendoza.

Material examined.

Argentina. Holotype ♀: Chubut, ruta 24 entre Sarmiento y Paso de Indios, 44°37'35.20S, 69°7'30.10W, 529 m s.n.m., XII-2010, Genise col. (MACN); 2 ♀ paratypes, Chubut, Pampa Pelada, 45°4'54.89S, 68°2'48.68W, 20-XII-2010, Genise col. (MACN); 1 ♀ paratype, Patagonia, San Jorge (the San Jorge Gulf occupies the southern part of the province of Chubut and the northern part of the province of Santa Cruz) (MACN); 1 ♂ (tentatively associated) Patagonia, San Jorge (MACN); 1 ♀ paratype, Santa Cruz, ruta 3, El Salado, 22-II-1980, Willink, Fidalgo, Dominguez & Claps col. (IFML); 1 ♀ paratype, Mendoza, Ruta Termas Sosneado km 42, 11-I-1980, Willink, Fidalgo, Dominguez & Claps col. (IFML).

Figures

Figures 20 - 24. Trichothurgus bolitophilus Durante & Roig Alsina, sp. n. 20 female holotype, habitus 21 female paratype Pampa Pelada, face 22 female paratype Pampa Pelada, detail of clypeus and facial prominence 23 female paratype Pampa Pelada, labrum: k, median longitudinal keel; p, paramedian carina; l, lateral carina; f, longitudinal furrow; c, preapical constriction 24 male, face.