Bombus ladakhensis Richards, 1928

Figs 6, 16, 139–147, 198

Bombus rufofasciatus var. [not subsp.] ladakhensis Richards, 1928b: 336, but not infrasubspecific after

Tkalců (1974a): 335 (ICZN 1999: Art. 45.6.4.1).

Bombus rufofasciatus var. [not subsp.] phariensis Richards, 1930: 642, but not infrasubspecific after

Tkalců (1974a): 336 (ICZN 1999: Art. 45.6.4.1).

Bombus variopictus Skorikov, 1933a: 248 .

Bombus variopictus subsp. bianchii Skorikov, 1933a: 248 .

Bombus reticulatus Bischoff, 1936: 7 .

The name Bombus variopictus was first published without description by Skorikov (1923) and the taxon was not described with a name available at the time until Skorikov (1933a).

Williams (1991) regarded the yellow-banded taxon ladakhensis s. str. and the white-banded taxon phariensis as parts of the same species based on similarity in morphology. There is also a tendency for some individuals from Yunnan to have much more extensive black hair.

Our PTP analysis (Fig. 10) of coalescents in the COI gene supports a single candidate species that includes both the taxon ladakhensis s. str. and the taxon phariensis, corroborated by differences in morphology.

From morphology, there is only the difference in colour pattern (pale bands yellow or white) between the taxon ladakhensis s. str. and the taxon phariensis. These taxa share the uniquely fused reflexed head of the male penis valve. They are considered parts of the single species, B. ladakhensis s. lat.

Diagnosis

Females

Queens medium-sized body length 16–19 mm, workers 9–13 mm. Can be distinguished on the QTP by their combination of the hair on the side of the thorax predominantly yellow or white extending

ventrally as far as the leg bases (cf. B. rufofasciatus, B. prshewalskyi) with the hair of T5 white (or at least extensively white tipped).

Males (Fig. 6)

Body length 11–13 mm. Can be distinguished on the QTP by their combination of either T1 yellow or T2 white (cf. B. rufofasciatus, B. prshewalskyi) with the hair of T6–7 white or at least extensively white tipped. Genitalia (Fig. 198) with the gonostylus as long as broad, reduced as a rounded flat scale with the inner basal process reduced to a tooth (cf. rufipes- group, festivus- group, rufofasciatus -group); volsella with the inner distal corner broadly produced but without a narrow hook (cf. rufipes- group, festivus- group, rufofasciatus -group); penis valve with the recurved hook of the head fused throughout most of its length to the adjacent penis-vale shaft (cf. all other Melanobombus); eye unenlarged relative to female eye.

Material examined

Holotype

INDIA • ♀ (queen, not a worker), holotype of Bombus rufofasciatus var. ladakhensis Richards, 1928 by monotypy (Williams 1991); Kashmir, Ladakh, Chushal; Jun. 1925; R. Meinertzhagen leg.; NHMUK (examined PW).

Material sequenced (24 specimens)

CHINA – Qinghai Province • 1 ♀ (worker); Xiangpishan; 36.7589° N, 99.6041° E; 30 Aug. 2010; P. Williams leg.; BOLD seq: 6876H04; PW: ML19 • 1 ♀ (worker); same collection data as for preceding; BOLD seq: 6876H05; PW: ML20 • 1 ♀ (worker); Kunlun Shan; 35.6920° N, 94.052° E; 13 Aug. 2013; P. Williams leg.; NHMUK seq: NHM2; PW: ML22 • 1 ♀ (worker); Burhan Budai Shan, Qushiang; 35.8304° N, 98.0816° E; 16 Aug. 2013; P. Williams leg.; BOLD seq: 1555C02; PW: ML233 . – Xizang Province • 1 ♀ (queen); Tanggula Shan; 32.8614° N, 91.9174° E; 29 May 1999; K. Huber leg.; BOLD seq: 1552H05; OLML: ML208 • 1 ♀ (queen); Sugela [= Shogu La]; 29.9154° N, 90.1421° E; 24 Aug. 1999; K. Huber leg.; BOLD seq: 1552H04; OLML: ML209 • 1 ♀ (queen); Mt Kailas; 30° N, 82° E; 16 Jul. 2004; T. Bardell leg.; BOLD seq: 1555G10; PW: ML300 • 1 ♀ (worker); Sejilashan; 29.64141° N, 94.69818° E; 26 Jul. 2018; Z. Ren leg.; KIB seq: SJLSM102012; KIB: ML544 • 1 ♀ (worker); Milashan; 29.85301° N, 92.33378° E; 27 Jul. 2018; Z. Ren leg.; KIB seq: MLSH103002; KIB: ML545 • 1 ♀ (worker); Yelashan; 30.16394° N, 97.2860° E; 22 Jul. 2018; Z. Ren leg.; KIB seq: YLSH202002; KIB: ML546 . – Sichuan Province • 1 ♀ (worker); Hongyuan; 32.3282° N, 102.4543° E; 3 Aug. 2002; P. Williams leg.; BOLD seq: 1555G12; PW: ML302 • 2 specs; Hongyuan; 32.3282° N, 102.4543° E; Y. Dong leg.; YD seq: DYX24.1, DYY28; YD: ML438, ML439 • 1 ♀ (worker); Que’er shan; 31.94192° N, 98.93244° E; 4 Aug. 2018; Z. Ren leg.; KIB seq: QESH304003; KIB: ML547 . – Yunnan Province • 1 ♀ (worker); Baima Snow Mountain; 28.37252° N, 98.99982° E; 16 Jul. 2018; Z. Ren leg.; KIB seq: BMXSH102017; KIB: ML543 • 9 ♀♀; Baima Snow Mountain; 28.3373° N, 99.0771° E; 14–18 Aug. 2019; M. Orr leg.; IOZ seq: 14F5 to 14F8, 14F10, OR15, OR17, OR22, OR26; IOZ: ML590 to ML598 .

Global distribution

(Qinghai-Tibetan-Plateau species) East Asia: CHINA: Xizang, Qinghai, Gansu, Sichuan, Yunnan. – Himalaya: INDIA: Kashmir, Uttaranchal, Sikkim; NEPAL. (IAR, INHS, IOZ, NHMUK, NMS, OLML, PW, SC, USNM, YD, ZIN, ZMHB.) The species is usually not common.

Behaviour

Food-plant generalists (Williams 1991; Williams et al. 2009; An et al. 2014). The male mate-searching behaviour is expected to resemble the patrolling of B. keriensis .