Bombus tanguticus Morawitz 1887
Creators: name: Williams, Paul H.
name: Altanchimeg, Dorjsuren
name: Byvaltsev, Alexandr
name: Jonghe, Roland De
name: Jaffar, Saleem
name: Japoshvili, George
name: Kahono, Sih
name: Liang, Huan
name: Mei, Maurizio
name: Monfared, Alireza
name: Nidup, Tshering
name: Raina, Rifat
name: Ren, Zongxin
name: Thanoosing, Chawatat
name: Zhao, Yanhui
name: Orr, Michael C.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Apidae
Bombus
Bombus tanguticus

description: Bombus tanguticus Morawitz, 1887
Figs 13, 103–107, 206
Bombus tanguticus Morawitz, 1887: 200.
Our PTP analysis (Fig. 10) of coalescents in the COI gene supports a single species B. tanguticus within the tanguticus- group as identified in the four gene species tree (Figs 21–22), corroborated by differences in morphology.
Bombus tanguticus has a distinctive morphology and has been placed in a separate subgenus, Tanguticobombus (Pittioni 1939b), although this was synonymised with the subgenus Melanobombus by Richards (1968). A close relationship with other species of the subgenus Melanobombus is supported by an analysis of COI barcodes by Williams (2018), which like the tree for the COI gene here (Fig. 10), placed this species in the lapidarius -group. In contrast, when the species tree was estimated from four gene trees that include slower-evolving nuclear genes that can provide more reliable support for older relationships, B. tanguticus is placed in its own tanguticus -group next to the lapidarius -group (Fig. 21). Female morphology is inconclusive, because the labrum has a very narrow median groove and the posterior ocello-ocular areas are relatively unpunctured, which support grouping B. tanguticus with B. lapidarius. In contrast, the more densely hairy hind corbiculum and elongate hind basitarsus (as well as large queen body size) support a closer relationship of B. tanguticus with B. simillimus. Resolving this question might be possible with information from other genes, but it is very likely that the morphology of the male genitalia, once the male is described, will be diagnostic among the two species groups. This is one of the few bumblebee species world-wide for which the male still remains unknown (Williams 2018).
The typical colour pattern of this species is yellow banded, but a worker from Qinghai (ML219) has a white-banded colour pattern, as confirmed from their identical COI barcode sequences (Fig. 9).
Diagnosis
Females
Queens very large body length 22–28 mm, workers 12–13 mm. Can be distinguished in the QTP by their combination of labral lateral tubercles medially narrowing and projecting as small pointed pyramids, the median longitudinal furrow between them deep and unusually narrow, 0.2× as broad as the labrum, forming a triangular notch (broader for co-occurring B. tibeticus, B. (Sibiricobombus) semenovi Morawitz, 1887, B. (Sibiricobombus) asiaticus Morawitz, 1875 s. lat.); mandible lacking a distinct sulcus obliquus, the posterior notch (incisura) anterior to the posterior tooth very weak or absent; clypeus with many large punctures especially in the dorsal half, the apical impressions unusually deep; antennal segment 3 (A3) short, nearly equal in length to A5, and only 1.5 × as long as A4 (substantially longer for co-occurring B. tibeticus, B. semenovi, B. asiaticus s. lat.); the mid basitarsus with the posterior distal corner acute; hind tibia with the outer (corbicular) surface weakly reticulate and shining, for the queens uniformly covered (even in the centre) with dense short black fine branched hairs (these can become abraded for older queens and are few or absent in workers); hind basitarsus long and narrow, nearly 4× as long as its greatest breadth, the posterior edge almost straight in its distal 4⁄5, the posterior distal corner acutely produced (basitarsus shorter and broader for co-occurring B. tibeticus, B. semenovi, B. asiaticus s. lat.), the outer surface with the short hair black with only short side branches so that some of the shining outer surface is visible between them (cf. dense overlapping pale hair for B. tibeticus); T6 posteriorly with a subapical rounded (nearly circular) boss, the apex for workers truncated or for queens deeply and narrowly divided medially (T6 undivided for queens of co-occurring B. tibeticus, B. semenovi, B. asiaticus s. lat.).
Males
Unknown.
Material examined
Lectotype
CHINA • ♀ (queen), lectotype of Bombus tanguticus Morawitz, 1887 by designation of Williams (2018); Qinghai, “Bassin des gelb.[en] Flusses” (= source area of the Huang He, probably near Zhaling Hu: Williams 2018); [1884]; [N. Przhevalsky leg.]; ZIN (examined PW).
Material sequenced (3 specimens)
CHINA – Qinghai Province • 1 ♀ (worker); Xiangpishan; 36.7589° N, 99.6041° E; 30 Aug. 2010; P. Williams leg.; BOLD seq: 6875A06; PW: ML9 • 1 ♀ (worker); Kunlun Pass; 35.7258° N, 94.1626° E; 13 Aug. 2013; P. Williams leg.; NHMUK seq: NHMRC2; PW: ML219. – Xizang Province • 1 ♀ (queen); Kamba county (Z715 80 km); 28.2193° N, 88.7942° E; 10 Jul. 2018; Q.-T. Wu leg.; IOZ seq: BB11; IOZ: ML566.
Global distribution
(Qinghai-Tibetan-Plateau species) East Asia: CHINA: Xizang, Qinghai. – Himalaya: INDIA: Kashmir, Sikkim. (IAR, IOZ, NHMUK, PW, ZIN.) This is one of the highest recorded bumblebees in
the world, from an elevation of ca 5640 m a.s.l. (Williams 2018: along with B. tibeticus). The species is widely distributed but generally very rare (Fig. 206). There are data available for only 12 queens and 2 workers, including the two recent queens from Kamba county, Xizang, collected in 2018 (IOZ, examined PW).
Behaviour
Expected to be food-plant generalists but very few records known (Williams 2018). Males of B. tanguticus are expected to be flying during mid to late August, either visiting flowers or searching for mates in semi-arid habitats at elevations above 4500 m a.s.l. (Williams 2018). Males of the mountain species B. keriensis have been found patrolling near high ridges towards the upper end of the species’ elevational range (above 4000 m a.s.l.) in Kashmir (Williams 1991). Similar ‘hill-topping’ near high mountain ridges towards the upper end of its elevational range in the QTP is likely for B. tanguticus.
description: Published as part of Williams, Paul H., Altanchimeg, Dorjsuren, Byvaltsev, Alexandr, Jonghe, Roland De, Jaffar, Saleem, Japoshvili, George, Kahono, Sih, Liang, Huan, Mei, Maurizio, Monfared, Alireza, Nidup, Tshering, Raina, Rifat, Ren, Zongxin, Thanoosing, Chawatat, Zhao, Yanhui & Orr, Michael C., 2020, Widespread polytypic species or complexes of local species? Revising bumblebees of the subgenus Melanobombus world-wide (Hymenoptera, Apidae, Bombus), pp. 1-120 in European Journal of Taxonomy 719 on pages 67-69, DOI: 10.5852/ejt.2020.719.1107, http://zenodo.org/record/4064324