Colletes xizangensis sp. n.

(Figs 27 a–e, 32u)

Diagnosis. The female is well characterized and different from all other species of this group by the distinct punctation patterns on T1 (dispersed, shiny) and T2 (denser and finer, with punctures very fine and dense medially) (Fig. 27 e) in combination with its relatively large body size and the lack of black hairs. The male is unknown.

Description. Female, BL= 10.5mm (Fig. 27 a); head broader than long, HW: HL=62: 50 (Fig. 27 b); gena narrower than eye in lateral view, GW: EW=9: 11; width of metasoma as broad as that between tegulae, MtW: TW=65: 65. Clypeus broader than long, with sparse and irregularly dispersed punctation (Fig. 27 b); disc of scutum with irregularly dispersed punctation, i=1.0–2.0d (Fig. 27 c); malar area medially shorter than the width of mandible base, about 2/3 long as the width of mandible base; facial fovea narrower than width of antennal flagellum; vertex behind eye rounded; propodeum laterally covered with sparse long erect hairs, integumental sculpture completely visible; disc of T1 shiny, finely and extremely dispersed punctate, i=1.5–4.0d, the size of punctation different (Fig. 27 e); punctation on disc of T2 fine and dense medially (Fig. 27 e); T1–T5 with apical hair bands (Fig. 27 d), apical hair band on T1 medially uninterrupted, only narrowed (Fig. 27 e), T2 without broad basal hair band, apical hair band on T2 nearly 1/3 width as the exposed T2 (Fig. 27 d); sloping anterior and lateral anterior parts of T1 sparsely covered with erect long plumose hairs (Figs. 27 d, 27e). Antennal flagellum ventrally black (Figs. 27 a. 27b); tarsi of all legs blackish brown, other parts black. Face, vertex and scutum covered with yellowish brown erect long plumose hairs, pilosity on scutum not intermixed with black hairs (Figs. 27 a, 27c), mesepisternum covered with longer white plumose hairs (Fig. 27 a).

Male unknown.

Type material. Holotype: 1♀, China, Xizang, Lhasa Shi (91º54′E 29º36′N), 36600m, 2.VI.1960, coll. Chun- Guang Wang; Paratype: 1♀, China, Xizang, Gyamada (93º06′E 29º36′N), 3400m, 23.VII.1976, coll. Yin-Heng Han.

Distribution. China (Xizang) (Fig. 32 u).

Floral records. Unknown.

Etymology. Named after the type locality, Xizang (China).