28. Bombus (Thoracobombus) hedini Bischoff

(Figs 58, 59)

Bombus silvarum ssp. unicolor Friese, 1905:514 (not of Kriechbaumer, 1870:159 = B. barbutellus (Kirby)) . Bombus (Agrobombus) hedini Bischoff, 1936:15 (not of Bischoff, 1936:25 = B. bohemicus Seidl).

Nomenclature. The name hedini Bischoff (1936:15) was selected as the valid name for this species by Williams (1998) by the Principle of the First Reviser (ICZN, 1999).

Material examined. 6 queens, 1045 workers, 54 males (IAB).

Distribution in North China. Widely distributed within the zone from the edge of southern Neimenggu plateau, the Yanshan mountains, the Taihangshan mountains, the loess plateau, to the edge of the east Qinghai- Tibetan plateau. Abundant at medium elevations of the loess plateau in eastern Gansu and southern Ningxia. Common at medium elevations of the Bashang plateau in northern Hebei, at low to medium elevations of the Yanshan mountains in northnorthern Beijing, at medium elevations of the Lvliangshan mountains in Shanxi, and at medium elevations of the loess plateau in northwestern Shaanxi. Rare at medium elevations of the Jiudingshan forest park in Tianjin, at medium elevations of the Taihangshan mountains in Shanxi, at medium elevations of the Huanggangliang forest park of the southernmost of the Great Khingan mountains in Neimenggu, at the medium elevations of the edge of the sourthern Mu Us semi-desert in northern Shaanxi and northern Ningxia, and at medium elevations of the Baishuijiang nature reserve of southernmost Gansu, and at high elevations of the edge of the east Qinghai-Tibetan plateau in western Gansu. 137 localities (Fig. 58) between 232–3432 m (IAB).

Variation in North China. This species shows some variation in North China (see the key).

Similar species in North China. This species is similar in its brown colour pattern to B. pascuorum, B. schrencki, B. tricornis and B. atripes (see the key; Figs 55, 57, 59, 69, 71).

Distribution in China. Beijing, Tianjin, Hebei, Shanxi, Neimenggu, Shaanxi, Gansu, Qinghai, Ningxia (IAB).

Forage plants. ASTERACEAE: Cirsium shansiense, Cosmos bipinnatus, Helianthus annuus, Solidago canadensis, Saussurea sp.; FABACEAE: Astragalus bhotanensis, A. dahuricus, A. penduliflorus, Lespedeza bicolor, L. juncea, Medicago sativa, Melilotus albus, M. officinalis, Onobrychis viciifolia, Vicia amoena, V. unijuga; GENTIANACEAE: Halenia elliptica; LAMIACEAE: Dracocephalum heterophyllum, Elsholtzia ciliata, Leonurus japonicus, L. sibiricus, Phlomis sp., Salvia deserta, S. farinacea, Salvia sp., Stachys chinensis, S. japonica ? Vitex negundo; PAPAVERACEAE: Corydalis sp.; RANUNCULACEAE: Trollius chinensis; ROSACEAE: Potentilla chinensis, Rubus crataegifolius; SCROPHULARIACEAE: Euphrasia pectinata; THYMELAEACEAE: Wikstroemia chamaedaphne; VALERIANACEAE: Patrinia scabra .