Bombus (Sibiricobombus) semenovi Morawitz 1887, stat. rev.

2. Bombus (Sibiricobombus) semenovi Morawitz, 1887 stat. rev. Figs 1, 7–8, 18‒21, 91 Bombus Semenovi Morawitz, 1887: 198. Note 1. Bombus (Sibiricobombus) xionglaris Wang, 1982: 432. Syn. nov. Bombus (Subterraneobombus) duanjiaoris Wang, 1982: 444. Syn. nov. Bombus (Subterraneobombus) zhadaensis Wang, 1982: 444. Syn. nov. Bombus semenowii ‒ von Dalla Torre 1896: 546, unjustified emendation. Bombus (Sibiricobombus) oberti ‒ Williams 1991: 92, (in part) misidentification. Diagnosis Females Queens body length 20‒23 mm, workers 12‒13 mm. Colour pattern of the hair with the head, lower side of the thorax and legs predominantly black, metasomal T3‒4 either black or more or less extensively dull orange, thoracic dorsum anterior and posterior bands and T1‒2 yellow, T5 dull orange (Figs 18‒20). Morphology with labral furrow broad, 0.35 × the entire breadth of the labrum; antennal A3 length 2 × greatest breadth; hind basitarsus outer surface in the centre with short branched hairs dense, black and strongly overlapping so that reflections from the outer surface are interrupted; (in large individuals) T6 subapically medially with a deep narrow longitudinal groove. Males Body length 16 mm. Colour pattern of the hair similar to the female, with the head except the yellow vertex, legs predominantly black, thoracic dorsum anterior and posterior bands, anterior sides of the thorax, and T1‒2 yellow, metasomal T3 either black or more or less extensively dull orange, T4‒6 dull orange (Fig. 21). Morphology with the eye scarcely enlarged relative to the eye of a female bumblebee, from the dorsal aspect the eye separated from the lateral ocellus by more than 2× the ocellar breadth; S6 with the posterior margin in the middle with a shallow narrow concave indentation; volsella with the inner distal corner as a broad but obtusely pointed hook projecting posteriorly almost as far as the outer distal corner (Fig. 91). Type material Syntype of Bombus semenovi (lectotype designation by Podbolotskaya unpubl.) CHINA • ♀ (queen); Qinghai, “im Thale des gelben Flusses” [Yellow River, Huang He]; [1884]; N. Przhevalsky leg.; ZIN (examined PW). Holotype of Bombus (Sibiricobombus) xionglaris (by original designation) CHINA • ♂; Xizang, Nyalam; 31 May 1974; X. Zhang leg.; IZCAS (examined PW). Holotype of Bombus (Subterraneobombus) duanjiaoris (by original designation) CHINA • ♀ (worker); Xizang, Rutog; 23 Aug. 1976; F. Huang leg.; IZCAS (examined PW). Holotype of Bombus (Subterraneobombus) zhadaensis (by original designation) CHINA • ♀ (queen); Xizang, Zanda; 25 Jun. 1976; F. Huang leg.; IZCAS (examined PW). Material examined CHINA ‒ Qinghai • 1 ♀ (worker); Kunlun Shan Pass; 35.6920° N, 94.0520° E; 13 Aug. 2013; P. Williams leg.; PW, SB003 / NHMC08 • 2 ♀♀ (workers); Kunlun Shan; 35.9063° N, 94.4052° E; 18 Jul. 2017; IZCAS, SB040 / MOBBT3, SB089 / BB07 • 1 ♀ (worker); Kunlun Shan Pass; 35.6917° N, 94.0533° E; 19 Aug. 2013; IAR, SB016 /JH8. ‒ Xizang • 1 ♂; Tanggula Shan; 32.8614° N, 91.9174° E; 18 Aug. 2015; IAR, SB004 /JH13 • 1 ♀ (queen); Tanggula Shan; 32.8614° N, 91.9174° E; 29 Jun. 1999; K. Huber leg.; BOLD no.: 1552A07 (COI); LMOB, SB041 • 1 ♂; near Zhilong; 32.8614° N, 91.9174° E; 18 Aug. 2015; IAR, SB017 /JHNEW. INDIA ‒ Jammu & Kashmir • 1 ♀ (queen); Zanskar, Nimaling; 33.7927° N, 77.5881° E; 18 Aug. 1980; P. Williams leg.; BOLD no.: 1555D11 (COI); PW, SB014. Distribution Tibetan high montane species ‒ East Asia: INDIA: Kashmir & Jammu; CHINA: Xizang, Qinghai. (IAR, IZCAS, NHMUK, PW, ZIN.) Behaviour Because the male eye is scarcely enlarged relative to the eye of a female, as in most bumblebees, the male mate-searching behaviour is expected to be similar to the most widespread male “patrolling” behaviour (Awram 1970; Svensson 1979), as for B. tunicatus, compared with “racing” behaviour (below) (Williams 1991). It is also possible, but unrecorded, that the males might seek out colonies with young females. Taxonomic remarks Note 1 on the name B. semenovi Morawitz, 1887 stat. rev.: the type locality of B. semenovi is probably near the source of the Yellow River, in the river valley downstream from the Zhaling Hu in Qinghai. See the discussion of the type locality of B. (Melanobombus) tanguticus Morawitz, 1887 in Williams (2018). The taxon concept of the species B. semenovi stat. rev. here agrees with the recent interpretation of a species separate from B. oberti (Williams 2022a), presenting evidence that: (1) our PTP analysis supports independent species-level coalescents in the COI gene (Fig. 1); corroborated by (2) diagnostic morphological character states (see the keys). Queens show some variation from T3 black (Qinghai) to T3 predominantly orange-red, or at least with an orange-red fringe posteriorly (Zanskar, Kashmir, India). The taxa xionglaris, duanjiaoris and zhadaensis are re-descriptions of the taxon semenovi.