Bombus himalayanus (Skorikov)

Williams, Paul H., Huang, Jiaxing, Rasmont, Pierre & An, Jiandong, 2016, Early-diverging bumblebees from across the roof of the world: the high-mountain subgenus Mendacibombus revised from species’ gene coalescents and morphology (Hymenoptera, Apidae), Zootaxa 4204 (1), pp. 1-72 : 43-45

7. Bombus himalayanus (Skorikov)

( Figs 4 , 20 , 30 , 51, 53, 54 , 62 )

Mendacibombus varius Skorikov 1914:125 (not of Lepeletier de Saint-Fargeau 1832:381, = B. campestris (Panzer)) , typelocality citation (Cyrillic) ‘[pass Zodji-La, … along the river Sind above Sonamarg]’. Lectotype queen by present designation ZISP examined, (Cyrillic) ‘[Zodzi-La]’ (Zoji-La, Great Himalaya, India). Note 1. Synonymised with Bombus himalayanus (Skorikov) by Williams (1991).

[ Mendacibombus varius var. differens , var. sexfasciatus , var. formosulus Skorikov 1914:126 , infrasubspecific.]

Mendacibombus mendax subsp. himalayanus Skorikov 1914:127 , type-locality citation (Cyrillic) ‘[pass Kordong]’. Holotype queen by monotypy ZISP examined, ( Cyrillic ) ‘[pass Kordong ]’ (Khardung-La, Ladakh Range, India). Note 2.

Mendacibombus varius Skorikov; Skorikov 1923 :149; Skorikov, 1931:213; Skorikov 1933:2.

Bombus (Mendacibombus) mendax Subsp. himalayanus (Skorikov) ; Richards 1930:635.

[ Mendacibombus margreiteri himalayanus Skorikov; Skorikov 1933 :2, misidentification.]

Bombus (Mendacibombus) himalayanus varius (Skorikov) ; Williams, 1991:fig. 5 male.

Bombus (Mendacibombus) himalayanus (Skorikov) ; P.H. Williams 1991:41; P.H. Williams 1998:99; P.H. Williams 2004:no. 27; Suhail et al. 2009:3 [not seen].

Bombus himalayanus (Skorikov) ; Sabir et al. 2011:161 [not seen].

Note 1 ( varius ). Skorikov’s original description of several females of the taxon varius cites the type locality as the Sind valley above Sonamarg up to the Zoji-La pass in the Great Himalaya. The ZISP collection studied by Skorikov contains a queen that agrees with the original description and carries the labels: (1) white, handwritten (Cryrillic) ‘[[ Pass] Zodzi-La, Hi- / malaya> 3000 mt. / G. Jakobson] 12‒15.VI.12 ’; (2) white, printed (Cyrillic) ‘[k. Skorikova]’; (3) red, printed ‘ Holotypus ’; (4) white, handwritten ‘varius’; (5) red, handwritten ‘ Lectotypus Mendaci- / Bombus varius Skor. / design. Podbolotsk. ’ (M. Podbolotskaya, unpublished); (6) green, printed ‘ Mendacibombus / MD# 735 det. PHW’; (7) red, printed ‘ LECTOTYPE [female] / Mendacibombus / varius / Skorikov, 1914 / det. PH Williams 2012’; (6) white, printed ‘[female] Bombus / ( Mendacibombus ) / himalayanus / det . PH Williams 2012’. This specimen, which is complete, is regarded as one of Skorikov’s syntypes and is designated here as the lectotype in order to reduce uncertainty in the identity and application of the name.

A second queen collected at the Zoji-La by Jakobson in 1912 (MD#535, NHM, sent by Skorikov as part of an exchange with the NHM in 1934), closely similar in morphology, is designated here as a paralectotype and interpreted as conspecific.

Note 2 ( himalayanus ). Skorikov’s original description of the taxon himalayanus specifies that there was only one type specimen for the name himalayanus , so this specimen in the ZISP is regarded as the holotype by monotypy ( ICZN, 1999: Article 73.1.2).

Etymology. The species is named after the Himalaya, the mountain range at the southern edge of the Qinghai- Tibetan plateau.

Taxonomy and variation. The interpretation of this species is based here on evidence from DNA, as well as on the form of the female labrum (and between species on the form of the male genitalia). This disagrees with earlier concepts, diagnosed originally in terms of the hair colour pattern ( Skorikov, 1914), because the species appears to be much more variable in colour pattern than was originally understood.

Skorikov (1914) described a single queen of the taxon himalayanus s. str. (MD#731) from the Ladakh range as having the corbicula framed with black hairs, the pale bands and most of the side of the thorax lemon yellow, and the black band between the wing bases extensively intermixed with yellow hairs. One yellow-banded queen with more extensive black hair (MD#316) and a queen and a few older workers (MD#484‒489, 499, 4054, 4055) with more extensive yellow hair are known from elsewhere in Kashmir ( Williams, 1991). The yellow-banded dark queen from Ladakh yielded only a short COI sequence ( Fig. 13 : MD#316), although this is enough to support the inference from morphology by Williams (1991) that the taxon himalayanus s. str. and the taxon varius are parts of the same species. Skorikov (1914) also described a single male with a yellow thorax with black hairs between the wing bases from Kilian (Raskam range, Xinjiang) under the name himalayanus s. str.. Unfortunately this specimen could not be found in the ZISP collection (M. Podbolotskaya in litt.). But this is likely to be the same individual that Skorikov (1931:215) later listed from the ‘Raskemkette, Nordhang des Kilieng’ as Mendacibombus makarjini .

Other specimens are known from the Great Himalaya and Pir Panjal ranges with a similar banded colour pattern, but with more extensive black between the wing bases and on the side of the thorax, and with the pale bands on the thorax and often on T2 white (Skorikov’s taxon varius ). These specimens have similar morphology of the female labrum and have been interpreted previously as conspecific ( Williams, 1991). The short COI sequences available are sufficient to give support for this white-banded taxon being conspecific with the yellow-banded taxon himalayanus s. str. ( Fig. 13 : the white-banded taxon varius MD#675, 417 and the yellow-banded taxon himalayanus s. str. MD#316).

Males (known only for the white-banded taxon varius ) usually have the hair of T3‒7 orange at least in part, but occasionally the hair of T3‒7 predominantly black (MD#426) or (as visible in photographs) entirely black.

Diagnostic description. Wings nearly clear (cf. B. avinoviellus ). Female hair colour pattern: generally black, but with pale hair (yellow and/or grey-white) varying from completely absent from the head to covering most of the face but with at most only a few pale hairs on the anterior vertex of the head, in a transverse band anteriorly on the thoracic dorsum and extending laterally and ventrally to just below the wing base (occasionally much intermixed with black hairs and almost absent), or as white hair to half way down the side of the thorax, or to all of the way to the midleg base, often but not always in a transverse band posteriorly on the thoracic dorsum (scutellum; so the thoracic dorsum between the wing bases may have the hair entirely black, or rarely may have many pale hairs intermixed), on T1‒2 (T1 is more often yellow than T2 or the thoracic bands, so that individuals may have both yellow and white hair), T3 with orange hair as a posterior fringe and throughout T4‒6, T3 laterally with black hair that often extends onto T4 and even T5 laterally (cf. B. avinoviellus ), T6 medially with black hair and often entirely black. Hindleg tibia with corbicular fringes usually black, but sometimes with a few hairs in the fringes orange-tipped or rarely more extensively pale-tipped. Female morphology: labrum with the basal depression narrow, the transverse ridge broader medially than the basal depression, in the median third subsiding only slightly with large punctures overflowing across it from the basal depression, the lateral tubercles laterally with scattered large and medium punctures ( Fig. 20 ) (cf. B. avinoviellus ). Clypeus in its central half with scattered punctures, small punctures spaced sparsely by more than their own widths (cf. B. avinoviellus ), the anterior depressions with a narrow band of dense punctures that is only one or two punctures in breadth (cf. B. avinoviellus ). Male morphology: genitalia ( Fig. 30 ) with the volsella distally rounded (finger-shaped) and curled back dorsally but not anteriorly; volsella at its broadest near the midpoint of its length, the dorsal surface just distal to this point without a raised curved ridge just inside the inner margin; volsella with the apex broad, broader than the adjacent penisvalve head, but with the apex narrowly produced and finger-like. Gonostylus from the dorsal aspect rectangular, with a distinct outer distal corner. Penis-valve inner shoulder located at Ĺ 0.5× the length of the penis valve from the distal end to the broadest point of the spatha; penis valve proximal to the outer shoulder <2× as broad as the penis-valve head; penis-valve breadth just proximal to the penis-valve head 0.11× the length of the penis valve distal to the broadest point of the spatha.

Material examined. 16 queens 72 workers 9 males, from India and Pakistan ( Fig. 62 : NHM, OLL, PW, ZISP), with 3 specimens sequenced (interpretable sequences listed in Figs. 11–13 ).

Habitat and distribution. Flower-rich alpine grassland, at elevations 2077‒(3307)‒ 4800 m a.s.l.. A species of the Karakorum and west Himalayan mountains. Compared to B. avinoviellus , the distribution of B. himalayanus extends slightly further to the north but less far to the east and it tends to occur at higher elevation (and the two species rarely occur together at precisely the same site). There is some overlap with B. marussinus in the northwestern Karakorum, but the two species seldom occur together. Bombus himalayanus replaces the eastern B. waltoni in the higher wet alpine zone of the western Himalaya. A regional distribution map is available for Kashmir ( P.H. Williams 1991). The yellow-banded taxon himalayanus s. str. from Ladakh appears to be very rare.

Food-plants. Williams (1991).

Behaviour. Williams (1991), mate-searching male shown in Fig. 4.

Figures

FIGURE 13. Assigning names to species from an estimate of phylogeny for 130 COI sequences of the subgenus Mendacibombus. Based on a BEAST analysis of the 30 unique haplotypes (Fig. 11), with the remaining sequences interpolated back into the tree with 0 branch lengths from their matching samples (where a sequence matches more than one longer sequence within a species in the Collapse results, it is added after the first matching sequence, with the addition of the two short-sequence yellow unbanded specimens from Pakistan, MD # 4058, 4059). The sequence labels follow the format used in Figs 11, 12. Lineages accepted as species from the GMYC models (Fig. 11) are shown as thick branches, the most recent common ancestors of each species are shown with a black spot, and branches within species are shown as thin branches. Asterisks mark samples used as informal proxies for the type specimens of each of the taxon names (Table 1). The proxy sample for the type specimen for the oldest available name (the valid name) for each species (from Fig. 11) is marked in bold. The interpretations of the species with their valid names are shown in grey to the right.

FIGURES 1 ‒ 6. Views of perching males of species of the subgenus Mendacibombus, showing the anteriorly extended antennae and laterally extended wings that are characteristic of their form of male mate-searching behaviour: 1, B. waltoni at Diebu ca 3910 m, Minshan mountains, Gansu, China, 29. viii. 2009; 2, B. convexus at Diebu ca 3340 m, Minshan mountains, Gansu, China, 29. viii. 2009; 3, B. avinoviellus at Gulmarg ca 2700 m, Pir Panjal mountains, Kashmir, India, 16. viii. 1985; 4, B. himalayanus at Apharwat ca 4100 m, Pir Panjal mountains, Kashmir, India, 30. viii. 1986; 5 ‒ 6, B. margreiteri near Dulan ca 3520 m, Burhan Budai mountains, Qinghai, China, 31. viii. 2010. Photos by PW (Figs 3 – 4 are the best available for these species).

FIGURES 15 ‒ 23. Morphology of the female (queen) head from the ventral aspect (labrum and mandibles): 15, B. marussinus queen, Pakistan MD # 482; 16, B. avinoviellus queen, India MD # 598; 17, B. turkestanicus queen, Tajikistan MD # 320; 18, B. defector queen, Kyrgyzstan MD # 1080; 19, B. margreiteri queen, Mongolia MD # 319; 20, B. himalayanus queen, India MD # 453. Morphology of the female (queen) left hindleg tibia from the left lateral aspect, dorsal at the top of the image, anterior to the left: 21, B. defector, China MD # 1251; 22, B. margreiteri, Mongolia MD # 319; 23, B. turkestanicus, Kyrgyzstan MD # 324.

FIGURES 24 ‒ 35. Morphology of the male genitalia for species of the subgenus Mendacibombus from the dorsal aspect, anterior to the left of the image, posterior to the right: 24, B. superbus, China MD # 339; 25, B. waltoni, China MD # 216; 26, B. convexus, China MD # 215; 27, B. makarjini, Kazakhstan MD # 1240; 28, B. marussinus, Pakistan MD # 408; 29, B. avinoviellus, India MD # 404; 30, B. himalayanus, India MD # 426; 31, B. turkestanicus, China MD # 351; 32, B. defector, Kyrgyzstan MD # 367; 33, B. margreiteri, China MD # 294; 34, B. handlirschianus, Russia MD # 835; 35, B. mendax, Spain MD # 689.

FIGURES 36 ‒ 55. Morphology of parts of the male genitalia from the dorsal aspect of the left side, anterior to the left of the image, posterior to the right, white bars indicating morphological characters referred to in the key to males: 36, B. waltoni; 37, B. mendax; 38, B. superbus; 39, B. convexus; 40, B. waltoni; 41, B. convexus; 42, B. defector; 43, B. mendax; 44, B. mendax; 45, B. turkestanicus; 46, B. avinoviellus; 47, B. mendax; 48, B. mendax; 49, B. makarjini; 50, B. handlirschianus; 51, B. himalayanus; 52, B. turkestanicus; 53, B. himalayanus; 54, B. himalayanus; 55, B. marussinus.

FIGURES 56 ‒ 67. Maps of the global distributions of species of the subgenus Mendacibombus from the material examined, with grey spots for specimen records and black spots for the samples with COI sequences (each species is unknown from regions outside the map boundaries shown); grey crosses for records of all species of Mendacibombus combined. Relief map with hill shading, Cartesian orthonormal projection, grey lines show borders to national administration according to UN maps, north at the top of the map. Image created in ArcGIS using World _ Shaded _ Relief basemap © 2014 Esri.

FIGURES 11 ‒ 12. Recognising species from an estimate of phylogeny for 30 unique COI haplotypes of the subgenus Mendacibombus by BEAST, using GMYC models and the PTP procedure. From the GMYC models (11), the single threshold T is shown by the vertical grey bar so that the intersecting lineages are interpreted as indicating 12 separate species (black spots at coalescent nodes; outgroups not shown). Values below the nodes of the maximum clade-credibility tree are Bayesian posterior probabilities showing branch support (groups with values <0.8 are considered unreliable) from the BEAST analysis with two billion MCMC generations and a 1 % burn-in. The x - scale axis is calibrated in substitutions per nucleotide site. From the PTP procedure (12), the Bayesian PTP solution with highest support also indicates 12 species. Values above the nodes are PTP Bayesian support values that all daughter haplotypes are parts of a single species; values below the nodes are Bayesian posterior probabilities showing branch support. The scale bar is calibrated in substitutions per nucleotide site. Each unique haplotype is represented by one of the longest available sample sequences, labelled with: the sequence length in number of base pairs, a taxon name or name for an unpublished colour pattern (light / dark / yellow / white / pale), and then a code that consists of a specimen identifier (MD #) from the project database and (after the hyphen) a sample identifier from BOLD or from GenBank, followed with its geographic origin.

FIGURE 7. Frequency of specimen collection by decade among specimens examined for species of the subgenus Mendacibombus excluding B. mendax and B. handlirschianus.

FIGURE 8. Plot of (y axis) terminal branch lengths from a tree for 43 unique COI haplotypes obtained with BEAST against (x axis) lengths of the barcode sequences in numbers of nucleotides.