Bombus (Sibiricobombus) longiceps Smith 1878, stat. rev.

9. Bombus (Sibiricobombus) longiceps Smith, 1878 stat. rev. Figs 1, 7, 9, 52‒71, 98 BOMBUS LONGICEPS Smith, 1878: 8. Stat. rev. Sibiricobombus flavodorsalis Skorikov, 1933: 248, not of Franklin, 1913 (= B. pensylvanicus (DeGeer, 1773)). Syn. nov. Sibiricobombus oshanini Skorikov, 1933: 248. Syn. nov. Bombus (Sibiricobombus) huangcens Wang, 1982: 430. Syn. nov. Bombus (Sibiricobombus) asiaticus ‒ Williams 1991: 87, (in part) misidentification. Diagnosis Females Queens body length 17‒20 mm, workers 11‒15 mm. Colour pattern with the hair of the head and legs black, beneath the base of the hind wing bases either usually yellow or white or rarely black, thoracic dorsum either bright yellow or bright yellow with a black band between the wing bases or white with a black band between the wing bases, metasomal T2 either part yellow or part white, with black at least intermixed along the midline, T3 black, T4‒5 either usually predominantly orange or rarely white or black (Figs 52‒61). Morphology with the oculo-malar area anteriorly only sparsely covered with small to medium punctures scattered irregularly; clypeus with the anterior lateral corners with a large patch of large punctures spaced by their own breadths with a dense patch of many small and medium punctures between them; antennal A3 length 3 × greatest breadth; ocello-ocular area with a broad band of dense fine punctures along the inner eye margin, this band along its inner edge without medium and large punctures; hind tibia outer corbicular surface in its upper proximal half coarsely sculptured and matt, so that reflections are much interrupted by the prominent sculpturing; hind basitarsus outer surface with short branched hairs not especially dense and partly overlapping so that reflections from the outer surface are partly obscured; (in large individuals) T6 subapically medially with a raised boss. Males Body length 13‒17 mm Colour pattern with the hair on the head black except on the clypeus either yellow or white, hair of the side of the thorax either yellow or white, thoracic dorsum either bright yellow or bright yellow with a black band between the wing bases or white with a black band between the wing bases, hair of the legs predominantly black, metasomal T 2 in part either yellow or white or black, T4‒6 either usually predominantly orange or rarely black (Figs 62‒71). Morphology with the eye greatly enlarged relative to the eye of a female bumblebee, from the dorsal aspect the eye separated from the lateral ocellus by 1× the ocellar breadth; S6 with the posterior margin in the middle with a deep concave indentation; gonocoxa from the dorsal aspect distally as broad as adjacent spatha, gonostylus distal lobe approximately square, volsella posterior to the gonostylus narrowed and angled inwards towards the body midline, volsella beyond the gonostylus narrowing to less than its breadth between the distal posterior corners, penis-valve head on its inner side ventrally at the base without a projecting angle, this angle only marked dorsally, penis-valve shaft at its proximal base on its outer side with a deeply marked ‘S’-shaped step, penis-valve head recurved section nearly straight posteriorly at the base (Fig. 98). Type material Lectotype of Bombus longiceps (by designation of Frison 1935: 340) INDIA • ♀ (large worker, not a queen); Kashmir, Ladakh Leh; [Aug. to Sep.]; F. Stoliczka leg.; NZSI (examined PW). Syntypes of Sibiricobombus flavodorsalis INDIA • ♀♀ (queens), Kashmir, Ladakh, Suru valley; ZIN (type not seen but identity not in doubt). Syntypes of Sibiricobombus oshanini INDIA • ♀♀ (queens), 1 ♂, Kashmir; Ladakh, Nubra valley; ZIN (type not seen but identity not in doubt). Holotype of Bombus (Sibiricobombus) huangcens (by original designation) CHINA • ♀ (queen); Xizang, Zanda; 28 Jun. 1976; F. Huang leg.; IZCAS (examined PW). Material examined CHINA ‒ Xizang • 2 ♀♀ (workers); Burang, Lalongba; 30.2060° N, 81.2523° E; 22 Jul. 2018; IZCAS, SB093 /BB24, SB090 /BB02. INDIA ‒ Himachal Pradesh • 1 ♀ (queen), 2 ♂♂; Saichu Nalla; 31.6000° N, 78.2670° E; 8 Sep. 1986; A. Hutchings leg.; BOLD nos.: 6880D12, 6880E01, 6880E02 (COI); PW, SB073 to SB075. – Kashmir & Jammu • 1 ♀ (queen); Zanskar, Padum; 33.4746° N, 76.8871° E; 30 Jul. 2007; R. Raina leg.; BOLD no.: 1552D10 (COI); RR, SB050 • 1 ♀ (queen); Kashmir, Kazalwan; 34.6464° N, 74.7171° E; 19 Jun. 2007; R. Raina leg.; BOLD no.: 1552E03 (COI); RR, SB046 • 2 ♀♀ (queens); Kashmir, Shah Pora; 34.6552° N, 74.8942° E; 28 Jun. 2009; R. Raina leg.; BOLD nos: 1552D07, 1552D09 (COI); RR, SB047, SB051 • 1 ♀ (queen); Kashmir, Baltal; 34.2648° N, 75.4366° E; 14 Jul. 2008; R. Raina leg.; BOLD no.: 1552D06 (COI); RR, SB048 • 1 ♀ (worker); Kashmir, Gulmarg; 34.0548° N, 74.3856° E; Aug. 1985; P. Williams leg.; BOLD no.: 6880C05 (COI); PW, SB054. PAKISTAN • 1 ♀ (worker); Skardu; 35.2903° N, 75.6444° E; 31 Aug. 2017; S. Jaffar leg.; BOLD no.: 1552E12 (COI); SJ, SB049 • 1 ♀ (worker); Hindu Kush, Shanduz Pass; 36.0756° N, 72.5200° E; 5 Jul. 2004; V. Gurko leg.; BOLD no.: 6880F07 (COI); MM, SB080. Distribution West Himalayan species ‒ East Asia: AFGHANISTAN; PAKISTAN; INDIA: Kashmir & Jammu, Himachal Pradesh, Uttarakhand, Sikkim; NEPAL; CHINA: Xizang. (IZCAS, NHMUK, NKME, PW, SMF, ZIN, ZSI.) Behaviour The male eye is greatly enlarged relative to the eye of a female bumblebee and the male antenna is strongly elongated, which is related to the male mate-searching behaviour described for this species (under the misidentified name of B. asiaticus) as “racing behaviour” by Williams (1991). Uniquely (as far as is known), males of this species were found to congregate in groups of up to 10 individuals among grass roots to spend the night torpid, with individually numbered males switching between clusters on successive nights (although this could be the result of disturbance) (Williams 1991: 23). Taxonomic remarks The taxon concept of the species B. longiceps stat. rev. here agrees with the recent interpretation of a species separate from B. asiaticus, B. falsificus stat. rev., B. obtusus, and B. tescorum nom. nov. et stat. rev. (Williams 2022a), presenting the details of 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). That the asiaticus -group might consist of a series of species has been anticipated by Reinig (1940). The taxa flavodorsalis and oshanini are re-descriptions of the taxon (yellow unbanded colour pattern) longiceps stat. rev. The species-level coalescent in the COI gene (Fig. 1) also supports as conspecific the yellow-unbanded taxon longiceps s. str., the yellow-banded taxon huangcens, and the white-banded taxon (callophenax of authors other than Cockerell (1917) (= B. avinoviellus Skorikov, 1914, see Williams et al. 2016)). Sculpturing of the female hind tibia is slightly more coarse and the wings are darker in Kashmir white-banded bees than in yellow unbanded Ladakh bees. Conspecificity is corroborated by their clypeal sculpturing (see the keys). Williams (1991: 115–118) also described how in high mountain passes (near Nigagar and Lal Pani) of the Great Himalaya in Kashmir, where “white-banded” (Kashmir valley) and “yellow-unbanded” (Ladakh) populations meet and produce apparent intermediate colour patterns (and also show some black-tailed colour patterns), the frequencies of states for two out of three colour-pattern characters (for presence/absence of a black thoracic band; and tail red/black) in the haploid males predicted the frequencies in the diploid females (the prediction failed for white/yellow bands). These predictions would be expected to hold if there were simple bi-allelic coding with simple dominance. Crucially, this is consistent with the two regional populations interbreeding as parts of a single species.