Bombus (Pyrobombus) taiwanensis Williams, Sung, Lin and Lu, 2022

Williams, Paul H., Sung, I-Hsin, Lin, Yi-Jing & Lu, Sheng-Shan, 2022, Discovering endemic species among the bumblebees of Taiwan (Apidae, genus Bombus), Journal of Natural History 56 (5 - 8), pp. 435-447 : 438-442

Bombus (Pyrobombus) taiwanensis Williams, Sung, Lin and Lu sp. nov.

( Figures 1 , 2 )

urn:lsid:zoobank.org:act:726E8A64-28A2-4DD9-8801-651DED8BD495

[ Bombus sp. non descripta Chiu 1948: 71, 1♀ (worker) (TARI)]

[ Bombus (Pyrobombus) nr. hypnorum Starr, 1992: 149 , 3♀ (workers) 2♂ ( TARI)]

Bombus (Megabombus) trifasciatus Smith, 1852

Bombus wilemani Cockerell, 1911

Bombus (Megabombus) bicoloratus Smith, 1879

Bombus (Psithyrus) turneri (Richards, 1929 [ Psithyrus ]) Psithyrus monozonus (Friese, 1931) not of Friese 1909 [= B. lucorum (Linnaeus) ]

Bombus (Pyrobombus) taiwanensis sp. nov. *

Bombus (Pyrobombus) flavescens Smith, 1852

Bombus (Pyrobombus) sonani ( Frison, 1934 [ Bremus ])*

Bombus (Alpigenobombus) angustus Chiu, 1948 *

[ Bombus (Bombus) terrestris (Linnaeus, 1758) – introduced from Europe only in glass houses]

Bombus (Melanobombus) eximius Smith, 1852 Bombus latissimus Friese, 1910

Bombus (Melanobombus) formosellus ( Frison, 1934 [ Bremus ])*

Material examined. Holotype: 1♀ (queen), labels (1): white, printed in black ‘ Mt. Hehuan , South peak/(3100 m), Nantou Co.,/ Taiwan, VI-15-2019,/ I. H. Sung’; (2) white, printed in black ‘ Bombus taiwanensis /Williams, Sung, Lin & Lu sp. nov./det. Paul H. Williams’; (3) red, printed in black ‘ HOLOTYPE / ♀ / Bombus taiwanensis /Williams, Sung, Lin & Lu’; (4) white, printed in black ‘[barcode]/00214314’ ( TFRI) .

Paratypes: 1♀ (worker), labels: (1) white, printed in black ‘Mt. Hehuan, South peak/ (3100 m), Nantou Co,/ Taiwan, VI-15-2019,/I. H. Sung’ ; (2) white, printed in black ‘ Bombus taiwanensis /Williams, Sung, Lin & Lu sp. nov./det. Paul H. Williams’ ; (3) red, printed in black ‘ PARATYPE / ♀ / Bombus taiwanensis / Williams, Sung, Lin & Lu’; (4) white, printed in black ‘[barcode]/00214315’ ( TFRI). 1♀ (worker), labels (1): white, printed in black ‘ Mt . Hehuan, South peak/(3100 m), Nantou Co .,/ Taiwan, VI-15-2019 /I. H. Sung’; (2) white, printed in black ‘ Bombus taiwanensis /Williams, Sung, Lin & Lu sp. nov./det. Paul H. Williams’; (3) red, printed in black ‘ PARATYPE / ♀ / Bombus taiwanensis / Williams , Sung, Lin & Lu’; (4) white, printed in black ‘[barcode]/00214316’ ( TFRI). 1♀ (worker), labels (1): white, printed in black ‘Mt. Hehuan, South peak/(3100 m), NantouCo.,/ Taiwan, VI-15-2019,/I. H. Sung’ ; (2) white, printed in black ‘ Bombus taiwanensis / Williams, Sung, Lin & Lu sp. nov./det. Paul H. Williams’ ; (3) red, printed in black ‘ PARATYPE / ♀ / Bombus taiwanensis / Williams, Sung, Lin & Lu’; (4) white, printed in black ‘[barcode]/00214317’ ( TFRI). 1♀ (worker), labels (1): white, printed in black ‘ Mt . Hehuan, South peak/(3100 m), Nantou Co .,/ Taiwan, VI-15- 2019,/I. H. Sung’; (2) white, printed in black ‘ Bombus taiwanensis /Williams, Sung, Lin & Lu sp. nov./det. Paul H. Williams’; (3) red, printed in black ‘ PARATYPE / ♀ / Bombus taiwanensis / Williams, Sung, Lin & Lu’; (4) white, printed in black ‘[barcode]/00214318’ ( TFRI).

Compared material. 1♀ (worker), labels: (1) orange, printed in black ‘C. TAIWAN: Tsuifeng/ 2300 m. Nantou Hsien / 23‒25.VI.1983 /K.S. Lin & S.C. Lin’; (2) white, handwritten ‘nr. ardens ’; (3) white, handwritten ‘[worker] Bombus /(Pyrobombus)/ hypnorum /(Linnaeus)/ det. P.H. Williams /1991’; (4) green, printed in black ‘BOLD# ( BEE-BOL /BBW/ PHW)/ 1550A06-TWN’; (5) white, printed in black ‘[worker] Bombus /(Pyrobombus)/ taiwanensis / det. P.H. Williams /2021’ ( PHW). 1♂, labels: (1) orange, printed in black ‘C. TAIWAN: Tayuling/ 2560 m. Hualien Hsien / 9‒16.VI.1980 /K.S. Lin & B.H. Chen’; (2) white, handwritten ‘ ♂ Bombus /(Pyrobombus)/ hypnorum /(Linnaeus)/det. P.H. Williams /1991’; (3) green, printed in black ‘BOLD# ( BEE-BOL /BBW/ PHW)/1550A07-TWN’; (4) white, printed in black ‘ ♂ Bombus /(Pyrobombus)/ taiwanensis /det. P.H. Williams /2021’ ( PHW).

Etymology

Named for its occurrence in Taiwan, avoiding homonymy with earlier names in Bombus of formosanus, formosellus , formosulus and formosus.

Diagnosis

A predominantly black, orange-tailed bumblebee from Taiwan ( Figure 1 ). Within the hypnorum complex distinguished by ( Figure 1 ): female and male with the front, middle and hind leg basitarsi all with the integument lighter brown than the tibiae (vs darker like the rest of the body for B. hypnorum ); hair (pubescence) of the metasoma with all of terga 4‒6 a pale but dull sandy brown or very pale orange (vs white for B. hypnorum ). Female clypeus in the half nearest to the labrum smooth and shining with only a few large punctures, mostly spaced by much more than their own widths ( Figure 2 ) (vs large punctures often separated by only their own widths for B. hypnorum ). Male genitalia with the gonostylus inner anterior (basal) projection separated from the gonocoxa by less than the breadth of the recurved hook of the penis-valve head (vs separated by much more than the breadth of the recurved hook of the penis-valve head for B. hypnorum ).

Description

Female habitus illustrated in Figure 1 , body size small (worker body length 10‒12 mm), hair (pubescence) moderately long, wings nearly clear. Mandible with the distal notch anterior to the posterior tooth (incisura) very shallow and hardly marked. Oculo-malar area (‘cheek’ sensu Williams et al. 2014; not the gena) of medium length, 1.0× longer (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) than the breadth of the mandible at its base (breadth between and including the mandibular condyles). Clypeus weakly swollen ( Figure 2 ), its raised area nearly flat, the central area with few widely scattered large and medium punctures, 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 over its outer third by a broad band with a few mostly large punctures, spaced by more than their own widths, the smaller punctures between the larger punctures very few. 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; tergum 6 posteriorly rounded and not divided medially, with a small subapical dorsal boss. Colour pattern of the hair of the body predominantly brownish black. Head entirely black except for orange hairs anteriorly on the labrum and laterally on the mandibles. Thoracic dorsum anterior to the wing bases with paler but dark sandy brown hair intermixed, this paler hair extending down the side of the thorax anteriorly, and on the scutellum posteriorly; the front, middle and hind leg tibiae all with some hairs orange, the basitarsi all with the integument lighter brown than the tibiae and with more orange hairs. Hair of the metasoma with tergum 3 posteriorly and all of terga 4‒6 a pale but dull sandy brown or very pale orange.

Male body size small (body length 12 mm), hair (pubescence) moderately long, wings nearly clear. Colour pattern of the hair of the body predominantly dark brownish, almost black. Head and the thoracic dorsum anterior to the wing bases with paler but dull sandy brown hair intermixed, this pale hair covering the side of the thorax (mesepisternum), and on most of the scutellum; the front, middle and hind leg tibiae all with the long hairs orange, the basitarsi all with the integument lighter brown than the tibiae and with the long hairs orange. Hair of the metasoma with tergum 1 and all of terga 4‒7 a pale but dull sandy-brown or very pale orange. Male genitalia with the gonostylus nearly triangular, the inner anterior (basal) projection separated from the gonocoxa by less than 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 strongly tapered.

Distribution

Endemic to the mountains of Hsinchu, Nantou and Hualien counties, central Taiwan, at elevations of 2300‒3100 m .

Figures

Figure 1. Left lateral view of the holotype female (queen) of Bombus taiwanensis sp. nov. showing habitus.

Figure 2. Anterior view of the lower part of the head of the holotype female (queen) of Bombus taiwanensis sp. nov. showing (centre) the clypeal punctures.