(Figs 29D, 32A–F, 48A)

Colletes bhutanicus Kuhlmann, 2003b: 732 (holotype ♀: Bhutan, Thimphu, Phajodhing Gompa [ZMUA]).

Colletes bhutanicus; Niu et al. 2014b: 477; Ascher & Pickering 2021.

Diagnosis. Among the Colletes of Xizang, females of C. bhutanicus can be recognized by the combination of the following features: paraocular area with pale-yellow and black hairs intermixed, mesosomal dorsum with mostly pale-orange hairs and tegula pale-brown. The presence of basolateral circular depressions on the S6 is sufficient to distinguish males of C. bhutanicus from those of the other Tibetan Colletes, except C. bischoffi and C. collaris, from which the former can be differentiated by having the S7 with apicolateral lobes broader than genital gonobase (S7 lobes narrower than gonobase in both C. bischoffi and C. collaris) and the gonostylus with subparallel sides basally (gonostylus with converging sides basally in both C. bischoffi and C. collaris).

Material examined. Published records — BHUTAN, Bumtang District: Byakar Dzong, 2698 m, 5.x.1973, M Ripley, 1 ♀, [USNM]. Thimphu: Thimphu, Lungtenphu, 2300 m, 9.xi.1994, G Schulten, 1 ♂, [RCMK].

New records — CHINA, Xizang: Mêgog Xian, 29.20 95.30, 1920 m, 6.x.1982, L Zai, 1 ♀; 1.xi.1983, YH Han, 1 ♀. Mêgog Xian, Gedang, 29.20 95.30, 2000 m, 3.x.1982, YH Han, 3 ♀; 8.x.1982, YH Han, 1 ♀; 14.x.1982, YH Ha, 2 ♀; 16.x.1982, YH Han, 8 ♀.

Distribution. Western China (Xizang) and western Bhutan (Thimphu).

DNA barcode. Unavailable.

Floral hosts. Unknown.

Remarks. Colletes bhutanicus has been the most rarely collected species of to the C. succinctus group not only in Xizang but also in China at large.