Bombus (Pyrobombus) wolongensis Williams, Ren & Xie, 2022

Williams, Paul H., Dorji, Phurpa, Ren, Zongxin, Xie, Zhenghua & Orr, Michael, 2022, Bumblebees of the hypnorum-complex world-wide including two new near-cryptic species (Hymenoptera: Apidae), European Journal of Taxonomy 847, pp. 46-72 : 58-60

Bombus (Pyrobombus) wolongensis Williams, Ren & Xie sp. nov.

urn:lsid:zoobank.org:act:944777F5-62DD-416A-A778-7C6D1E189572

Figs 1–2 , 5‒9 , 51

[ Bombus (Pyrobombus) hypnorum ( Linnaeus, 1758) – Williams et al. 2009b: 157, (in part) misidentification.]

Diagnosis

Female distinguished by the combination: labral lamella narrow and deeply rounded, almost pointed in the middle; clypeus in the central area with scattered widely-spaced small punctures and the very large punctures spaced by more than three times their own diameter; ocello-ocular area along the inner eye margin with only one row of larger medium punctures; thoracic dorsum with the hair predominantly dull yellow with a dense central spot between the wing bases of black hair.

Male distinguished by the combination: hair of the thorax and metasomal T1‒2 yellow, T3‒4 black.

Etymology

Named for its occurrence near the area named Wolong, in Sichuan Province.

Material examined

Holotype CHINA • ♀ (queen) pinned; [four labels]; [(1) white hand-written in red] ‘6605’; [(2) white printed in black] ‘ CHINA: Sichuan / Leibo Co, Gudui 1711m / 28.47056N 103.31884E / J Wang’; [(3) green printed in black] ‘BOLD# / ( BEE-BOL / BBW / PHW) / 596G12-6605-CHN’; [(4) red printed in black] ‘HOLOTYPE ♀ (q) / Bombus wolongensis / Williams, Ren & Xie / det PH Williams 2022’; IOZ.

Material sequenced or examined CHINA • 1 ♀ (queen); Sichuan, Leibo Co., Gudui ; 28.4706° N, 103.3188° E; alt. 1711 m; 8 Apr. 2007; Z. Xie leg.; [#6603]; BOLD-596H01-0012-CHN ; PW • 1 ♀ (queen); Sichuan, Leibo Co., Gudui ; 28.4706° N, 103.3188° E; alt. 1711 m; PW • 1 ♂; Sichuan, Litang Co., Litang-Yajiang ; 30.0079° N, 100.3137° E; alt. 4382 m; 10 Jul. 2003; Y. Tang leg.; BOLD-1550A08-CHN ; PW • 1 ♂; Sichuan; Y. Tang leg.; [TY0700189]; PW • 1 ♂; Yunnan, Lijiang ; 29.0025° N, 100.1825° E; alt. 3200 m; 27 Jul. 2018; Z. Ren leg.; PW .

Description

Female

Habitus illustrated in Fig. 51 , body size small (queen body length 15‒17 mm, worker: no workers available to hand), hair (pubescence) moderately long, wings lightly clouded with brown. Mandible with the distal notch anterior to the posterior tooth (incisura) very shallow. Oculo-malar area (‘cheek’ sensu Williams et al. 2014; not the gena) of medium length, 1.0 × as long as the breadth of the mandible at its base (length measured between the ventral edge of the compound eye and the edge of the malar area at the articulation of the mandible midway between the mandibular condyles; breadth measured between and including the mandibular condyles). Labral lamella narrowly rounded and almost pointed in the middle. Clypeus weakly swollen, its raised area nearly flat, the central area with few widely scattered large, medium, and small punctures with intervening areas shining, few punctures especially medially and ventrally adjacent to the labrum. The area between the inner edge of the compound eye and the outer edge of the lateral ocellus occupied in just more than its outer third by widely spaced medium and small punctures, spaced by more than their own widths, the medium punctures in a single row. Mid basitarsus with the distal posterior corner broadly rounded; hind tibia outer surface with a corbicula, the surface sculpturing weakly reticulate so that the surface appears slightly matt; hind basitarsus in the distal three quarters covered with short branched decumbent and weakly overlapping hairs with golden reflections; metasomal T6 posteriorly rounded and not divided medially, with a small subapical dorsal boss. Colour pattern of the hair of the body predominantly black. Head entirely black, except for orange hairs anteriorly on the labrum and laterally on the mandibles, and a yellow fringe posteriorly on the occiput. Thoracic dorsum dull yellow (the exact shade varies but is lighter than for unfaded B. bryorum ), this pale hair not extending down the side of the thorax anteriorly, with black hair as a small or large dense central spot between the wing bases and often a few black hairs scattered laterally and especially anteriorly; the front, middle and hind leg tibiae all with the hairs predominantly black, the basitarsi all with the integument brown-black like the tibiae. Hair of T1 yellow, T2‒3 and T4 anteriorly black, T4 posteriorly and T5‒6 cream-white.

Male

Body size small (body length 11‒13 mm), hair (pubescence) moderately long, wings very lightly clouded with brown. Colour pattern of the hair of the body predominantly yellow. Front and top of the head with some black hair intermixed. Hair of metasomal T3‒5 with some black hair at least anteriorly, T5‒7 predominantly cream-white. Male genitalia with the gonostylus nearly triangular, the inner anterior (basal) projection separated from the gonocoxa by a distance equal to the breadth of the recurved hook of the penis-valve head; the volsella scarcely projecting beyond the gonostylus; the penis valve with the head recurved as a flattened sickle-shaped hook that is not tapering at the mid-point of its length.

Distribution

In the mountains of Sichuan and Yunnan, at elevations 1711‒4382 m (Williams et al. 2009). Uniquely for species pairs within the hypnorum -complex, this species shows an overlap in distribution range with B. hengduanensis in Sichuan and Yunnan.

Figures

Fig. 1. MRBAYES estimate of phylogeny as a metric tree (outgroup B. alpinus (Linnaeus, 1758) not shown) from COI barcodes from GenBank and BOLD databases for the vagans-group and hypnorum- group, with additions from the authors for the hypnorum-group of bumblebees, filtered to remove duplicate and short sequences. Each sequence is labelled with: sequence length; a taxon name from the database; a code consisting of a sequence identifier from the project database and a specimen identifier from the online database; its country and (for larger countries) state or province). The scale bar is calibrated in substitutions per nucleotide site. Results of Bayesian Poisson-tree-process (PTP) models applied for assessing support for species’ gene coalescents by maximum likelihood are shown as PTP scores above the branches: scores approaching 1 and where branches change from blue to red indicates are where the most likely species’ gene coalescents are detected. Asterisks mark sequences used as informal proxies for the type specimens of each of the taxon names in Table 2.

Fig. 2. Distribution of barcoded samples of the hypnorum-complex and B. perplexus Cresson, 1863, with the interpretations as separate candidate species from Fig. 1 shown as different coloured spots as per the colour key on the left. Relief map with hill shading, polar projection (north pole shown as a star), the international boundaries and the Arctic Circle are shown as narrow grey lines, and the northern tree line shown as a broad grey line. Image created in ArcGIS using World_Shaded_Relief basemap (© 2014 Esri).

Figs 3–38. Simplified diagrams for the colour patterns of the hair on the dorsum for ♀♀ (left) and ♂♂ (right) of the Bombus species from Fig. 2. The dorsum is divided into regions, each of which shows only the predominant or most apparent colour for that region using a simplified colour palette (precise shades vary), with olive indicating a mixture of black and yellow hair, and grey indicating a mixture of black and white hair.

Fig. 51. Bombus wolongensis Williams, Ren & Xie sp. nov., ♀ (queen), holotype (IOZ), habitus, lateral view (image reversed). Scale bar: 10 mm.