Bombus richardsiellus ( Tkalců, 1968 )

Williams, Paul H., Altanchimeg, Dorjsuren, Byvaltsev, Alexandr, Jonghe, Roland De, Jaffar, Saleem, Japoshvili, George, Kahono, Sih, Liang, Huan, Mei, Maurizio, Monfared, Alireza, Nidup, Tshering, Raina, Rifat, Ren, Zongxin, Thanoosing, Chawatat, Zhao, Yanhui & Orr, Michael C., 2020, Widespread polytypic species or complexes of local species? Revising bumblebees of the subgenus Melanobombus world-wide (Hymenoptera, Apidae, Bombus), European Journal of Taxonomy 719, pp. 1-120 : 60-61

Bombus richardsiellus ( Tkalců, 1968)

Figs 13 , 78–82 , 189 , 205

Pyrobombus richardsiellus Tkalců, 1968: 42 .

Our PTP analysis ( Fig. 10 ) of coalescents in the COI gene within the rufofasciatus -group supports nine species including B. richardsiellus , corroborated by differences in morphology (see the Diagnosis).

Females show size-dependent dimorphism in the colour pattern of the hair: large queens have metasomal T1–3 black, T4 anteriorly black and posteriorly white, and T5 white; whereas large workers (which are smaller) have T1 with some yellow hair, T2 anteriorly with at least a few yellow hairs, T4 orange-red, and T5 anteriorly orange-red, T5 posteriorly and T6 (in part) white; and small workers have white hairs intermixed on the face and on the side of the thorax, T1–2 predominantly yellow, and T5 almost entirely orange. Males have the thoracic bands and T1–2 yellow, T3 black, and T4–5 orange-red.

Diagnosis

Females

Queens medium-sized body length 20–21 mm, workers 10–15 mm. Can be distinguished in the Hengduan region by their combination of the hair of the thoracic dorsum with white bands, T1 black or yellow, and T5 posteriorly white (cf. B. rufofasciatus , B. prshewalskyi , B. miniatus , B. friseanus , B. pyrosoma ).

Males

Body length 12 mm. Can be distinguished by their combination of the thorax with yellow bands with the hair of T3 almost entirely black and without a yellow posterior fringe (cf. other rufofasciatus -group species). Genitalia ( Fig. 189 ) with the gonostylus much reduced, less than a quarter as long on its outer side as broad, with the distal edge concave, the inner distal corner with a single- or double-pointed projection, the inner proximal corner broad and nearly 90° (cf. B. miniatus , B. eurythorax , B. pyrosoma , B. formosellus ); volsella with the inner distal corner produced as a narrow curved hook. The single examined male specimen (NHMUK) is missing its head, but according to Tkalců (1968) this male had eyes unenlarged relative to the female.

Material examined

Holotype

BURMA • ♀ (queen), holotype of Pyrobombus richardsiellus Tkalců, 1968 by original designation; Adung Valley ; 8 Jul. 1931; Lord Cranbrook (= J. Gathorne-Hardy) leg.; NHMUK (examined PW).

Material sequenced (3 specimens)

CHINA • 1 ♀ (worker); Xizang, Nyingchi ; 30.0054° N, 95.2936° E; 12 Aug. 2012; NHMUK seq: NHMCT1 (sequence data from Williams 2018); PW: ML2 • 1 ♀ (worker); Xizang, Galonglashan ; 29.8266° N, 95.71532° E; 25 Jul. 2018; Z. Ren leg.; KIB seq: GLLSL203007; KIB: ML563 • 1 ♀ (worker); Xizang, Sangjiu ; 28.8089° N, 97.6056° E; 31 Aug. 2014; IBK seq: BB09; IOZ: ML581 .

Global distribution

(Hengduan mountain species) East Asia: CHINA: Xizang. – Southeast Asia: BURMA (north). (IAR, IOZ, KIB, NHMUK, PW.) Until recently, the species was known from only five specimens (two queens, two workers, and one male), most from the Adung Valley, Burma, with one queen from Zayul, Xizang (NHMUK, examined PW). Knowledge of this species has increased substantially recently with the collection of a queen and 14 workers from Sanjiu in Xizang in 2014 (IOZ, examined PW) and a collection of 64 workers from Galonglashan in Xizang in 2018 (KIB, examined PW), which brings the total known number of available specimens to 83. From this information, among bumblebee species with continental distributions, this species remains apparently unusually narrowly distributed ( Fig. 205 ).

Behaviour

Food-plant choice generalist (ZR unpublished).

Figures

Figs 12‒13. Maps of sequenced samples. 12. The rufipes-group and festivus-group. 13. The rufofasciatus- group as recognised as species from the UHF-PTP analysis in Fig. 10. Keys to the coloured symbols are shown on the left (in some cases symbols on the map for one species may overlie symbols for another). Maps projected onto a sphere in ArcGIS using World_Shaded_Relief basemap © 2014 ESRI and showing boundaries between countries as recognised by the UN.

Figs 64–102. Simplified diagrams for the colour patterns of the hair on the dorsum for the species from the integrative analysis. 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, with olive indicating a mixture of black and yellow hair, and grey indicating a mixture of black and white hair. The rufofasciatus-group. 64. Queen, China-Yunnan. 65. Queen, China-Sichuan. 66. Worker, China-Xizang. 67. Worker, China- Xizang. 68. Worker, China-Gansu. 69. Male, China-Yunnan. 70. Male, China-Xizang. 71. Queen, India- Kashmir. 72. Queen, India-Kashmir. 73. Queen, Pakistan. 74. Worker, India-Kashmir. 75. Worker, India- Kashmir. 76. Male, Pakistan. 77. Male, India-Kashmir. 78. Queen, Burma. 79. Worker, Burma. 80. Worker, China-Xizang. 81. Worker, China-Xizang. 82. Male, Burma. 83. Queen, China-Sichuan. 84. Worker, China-Sichuan. 85. Worker, China-Sichuan. 86. Worker, China-Sichuan. 87. Worker, China-Sichuan. 88. Worker, China-Xizang. 89. Male, China-Sichuan. 90. Male, China-Sichuan. 91. Queen, China-Beijing. 92. Queen, China-Beijing. 93. Worker, China-Shanxi. 94. Worker, China-Beijing. 95. Worker, China- Beijing. 96. Male, China-Beijing. 97. Male, China-Beijing. 98. Queen, China-Taiwan. 99. Worker, China- Taiwan. 100. Worker, China-Taiwan. 101. Worker, China-Taiwan. 102. Male, China-Taiwan.

Figs 181‒189. Morphology of the male genitalia for species of the subgenus Melanobombus von Dalla Torre, 1880 from the dorsal aspect, anterior at the bottom of the image, posterior at the top. 181. Bombus eximius Smith, 1852, China-Guangxi. 182. B. rufipes Lepeletier, 1835, Indonesia- Java. 183. B. festivus Smith, 1861, Nepal. 184. B. simillimus Smith, 1852, India-Himachal Pradesh. 185. B. miniatus Bingham, 1897, Bhutan. 186. B. eurythorax Wang, 1982 stat. rev., India-Kashmir. 187. B. prshewalskyi Morawitz, 1880 stat. rev., China-Sichuan. 188. B. rufofasciatus Smith, 1852, India- Kashmir. 189. B. richardsiellus (Tkalců, 1968), Burma (left volsella distal part missing). Scale bars = 1 mm.

Figs 205–206. Maps of all available global records with all of the specimens examined and confirmed here. 205. Bombus richardsiellus (Tkalců, 1968). 206. B. tanguticus Morawitz, 1887. Relief map with hill shading for the region centred on Tibet with (grey lines) borders to national administration as in UN maps. Image created in ArcGIS using World_Shaded_Relief basemap © 2014 Esri.

Fig. 10. October 2019 (Fig. 8) Bayesian PTP analysis of MrBayes tree of unique COI barcodes (UHF- PTP). Symbols as in Fig. 9.