Widespread polytypic species or complexes of local species? Revising bumblebees of the subgenus Melanobombus world-wide (Hymenoptera, Apidae, Bombus) Author Williams, Paul H. Natural History Museum, Cromwell Road, London SW 7 5 BD, UK. Institute of General and Experimental Biology, Peace Avenue 54 b, Ulaanbaatar 13330, Mongolia. Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090 Russia. Langstraat 105, B- 2260 Westerlo, Belgium. South China Agricultural University, Guangzhou 510642, China. Agricultural University of Georgia, 240 Agmashenebli Alley, Tbilisi, Georgia. Indonesian Institute of Sciences (LIPI), Jakarta, Indonesia. Kunming Institute of Botany (Chinese Academy of Sciences), 132 Lanhei Road, Kunming, Yunnan 650201, China. Università di Roma ‘ Sapienza’, Piazzale Valerio Massimo 6, Roma 00162, Italy. Yasouj University, Zirtol, Yasouj, Iran. Sherubtse College, Royal University of Bhutan, Trashigang, Bhutan. Zoological Survey of India, Pali Road, Jodhpur 342005, Rajasthan, India. Institute of Zoology (Chinese Academy of Sciences), 1 Beichen West Road, Chaoyang, Beijing 100101, China. paw@nhm.ac.uk Author Altanchimeg, Dorjsuren altanchimegd@mas.ac.mn Author Byvaltsev, Alexandr byvam@yandex.ru Author Jonghe, Roland De roland.de.jonghe@telenet.be Author Jaffar, Saleem saleemjaffar@stu.scau.edu.cn Author Japoshvili, George g.japoshvili@agruni.edu.ge Author Kahono, Sih sihkahono@gmail.com Author Liang, Huan lianghuan@mail.kib.ac.cn Author Mei, Maurizio Author Monfared, Alireza Author Nidup, Tshering Author Raina, Rifat Author Ren, Zongxin Author Thanoosing, Chawatat Author Zhao, Yanhui Author Orr, Michael C. text European Journal of Taxonomy 2020 2020-10-02 719 1 120 journal article 9775 10.5852/ejt.2020.719.1107 7ca72f76-4fae-4305-8601-4662f4cd2b96 4064324 A4500016-C219-4353-B81C-5E0BB520547F 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).