Bombus festivus Smith, 1861

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 : 49-51

Bombus festivus Smith, 1861

Figs 12 , 38–45 , 183

Bombus festivus Smith, 1861: 152 .

Bombus atrocinctus Smith, 1870: 193 .

Bombus terminalis Smith, 1870: 193 .

Bombus melaleucus subsp. discolor Friese, 1905: 514 .

Bombus handel-mazettii Pittioni, 1939a: 260 .

Bombus calidiformis Pittioni, 1939a: 262 .

Bombus festivus has a distinctive morphology and has been placed in a separate subgenus, Festivobombus ( Tkalců 1972) or Atrocinctobombus ( Skorikov 1933a: name published without description). A close relationship with other species of the subgenus Melanobombus was supported by an analysis of five genes by Cameron et al. (2007) and these subgenera were synonymised by Williams et al. (2008).

Our PTP analysis ( Fig. 10 ) of coalescents in the COI gene within the festivus- group supports a single species B. festivus , corroborated by differences in morphology (see the Diagnosis).

Females show pronounced size-dependent dimorphism in the colour pattern of the hair: large queens have the thoracic dorsum black with a large white patch in the middle (taxon festivus s. str.); whereas workers (which are smaller) and males have the thoracic dorsum extensively orange-brown (taxa atrocinctus and terminalis ). That these castes and sexes are conspecific has been confirmed from examining variation within a colony in Nepal ( Ito et al. 1984).

Diagnosis

Females

Queens large body length 22–26 mm, workers 12–17 mm. Can be distinguished by the hair of the thoracic dorsum either black with a large central white spot (queen) or extensively brown (worker), the wings dark brown, and both castes have the hind tibia with the distal posterior corner produced as a short spine (cf. B. hypnorum ( Linnaeus, 1758) , B. abnormis ( Tkalců, 1968)) .

Males

Body length 13–16 mm. Can be distinguished by the hair of the thoracic dorsum extensively brown, similarly coloured to the worker. Genitalia ( Fig. 183 ) with the gonostylus relatively undifferentiated, although the proximal inner projection is only weakly projecting towards the body midline and more strongly extending ventrally and distally beneath and parallel to the inner edge of the main body of the gonostylus as a shelf (similar to some Pyrobombus but more distinctly pronounced, cf. B. hypnorum , B. abnormis ); volsella with a pronounced inner distal corner forming a narrow hook ( cf. rufipes -group, lapidarius -group, sichelii -group, keriensis -group); penis valve head with the outer flange only weakly expanded (cf. non- festivus -group); eye unenlarged relative to female eye.

Material examined

Lectotype

INDIA • ♀ (queen), lectotype of Bombus festivus Smith, 1861 by designation of Tkalců (1974a); “N.[orth] W.[est]”; NHMUK (examined PW).

Material sequenced (18 specimens)

NEPAL • 1 ♀ (worker); Bheri, Dilikot ; 29.029° N, 81.749° E; 28 May 1995; M. Hartmann leg.; BOLD seq: 1551H10; NME: ML198 • 1 ♀ (worker); no data; BOLD seq: 6876H08; PW: ML197 .

BHUTAN • 1 ♀ (queen); Thimphu, Lungtenphu ; 27.4574° N, 89.6655° E; 17 Mar. 1996; H. Feijen leg.; BOLD seq: 6880H01; RMNH: ML505 • 1 ♂; Wangli , Pele-La; 27.5498° N, 90.2157° E; 16 Sep. 1994; G. Schulten leg.; BOLD seq: 6880H03; RMNH: ML507 • 1 ♀ (queen); Thimphu, Phajoding Gompa ; 27.479° N, 89.595° E; 25 Apr. 2018; J. Smit leg.; RMNH seq: 1092453; RMNH: ML570 • 1 ♀ (queen); same collection data as for preceding; RMNH seq: 1092451; RMNH: ML572 • 1 ♀ (queen); Wangdue Phodrang, Sephu ; 27.53° N, 90.245° E; 3 May 2018; J. Smit leg.; RMNH seq: 1092504; RMNH: ML571 .

CHINA – Yunnan Province • 1 ♂; Dali ; 25.75° N, 100.1° E; 8 Jul. 1996; C. Hauser leg.; BOLD seq: 1552A01; SMNS: ML181 • 1 ♀ (worker); Lijiang ; 27.0020° N, 100.182° E; 13 Jul. 2017; A. Moss leg.; BOLD seq: 1555C09; PW: ML240 • 1 ♂, 1 ♀ (worker); Lijiang ; 27.0156° N, 100.1714° E; 23 Jun. 2017; H. Liang leg.; KIB seq: 15; KIB: ML360 • 1 ♂; same collection data as for preceding; 11 Aug. 2016; KIB seq:16; KIB: ML361 • 1 ♂; same collection data as for preceding; 1 Aug. 2016; KIB seq: 17; KIB: ML362 • 1 ♂; same collection data as for preceding; 11 Aug. 2016; KIB seq:18; KIB: ML363 • 1 ♂; same collection data as for preceding; KIB seq: 19; KIB: ML364 • 1 ♂; same collection data as for preceding; 19 Jul. 2017; H. Liang leg.; KIB seq: 20; KIB: ML365 • 1 ♀; Baima Snow Mountain ; 28.3373° N, 99.0771°E; 14 Aug. 2019; M. Orr leg.; IOZ seq: 14F5; IOZ: ML583 . – Sichuan Province • 1 ♂; Luojishan ; 27.5811° N, 102.4028° E; 11 Aug. 2005; P. Williams leg.; BOLD seq: 1555E06; PW: ML254 • 1 ♀ (worker); same collection data as for preceding; BOLD seq: 1555E07; PW: ML255 .

Global distribution

(Himalayan, Hengduan, and west Chinese mountain species) East Asia: CHINA: Xizang, Gansu, Sichuan, Yunnan, Shaanxi, Chongqing, Hubei, Guizhou, Guangxi. – Himalaya: INDIA: Himachal Pradesh, Uttaranchal, Sikkim, Darjiling Bengal, Arunachal Pradesh; NEPAL, BHUTAN. – Southeast Asia: BURMA, VIETNAM. (AMNH, IAR, INHS, IOZ, KIB, KIZ, NHMUK, NME, NMS, PW, RMNH, SC, SEHU, SMNS, USNM, ZMUM.) The species is widely distributed and often abundant.

Behaviour

A colony of this species has been described from Nepal ( Ito et al. 1984). Food-plant generalists ( Williams et al. 2009; An et al. 2014). The male mate-searching behaviour is expected to resemble the patrolling of B. keriensis .

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 25–63. 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 rufipes-group. 25. Queen, China-Taiwan. 26. Queen, China-Guangdong. 27. Worker, China-Sichuan. 28. Worker, Thailand. 29. Queen, Nepal. 30. Male, China-Sichuan. 31. Male, China-Sichuan. 32. Male, Thailand. 33. Male, Nepal. 34. Male, Nepal. 35. Queen, Indonesia-Sumatra. 36. Queen, Indonesia-Java. 37. Male, Indonesia-Java. The festivus-group. 38. Queen, Nepal. 39. Queen, China-Sichuan. 40. Worker, China- Sichuan. 41. Worker, China-Xizang. 42. Worker, China-Yunnan. 43. Male, Nepal. 44. Male, China- Yunnan. 45. Male, China-Yunnan. The rufofasciatus-group. 46. Queen, India-Kashmir. 47. Worker, India-Kashmir. 48. Male, India-Kashmir. 49. Male, India-Kashmir. 50. Queen, India-Arunachal Pradesh. 51. Queen, Bhutan. 52. Worker, Bhutan. 53. Worker, Bhutan. 54. Male, Bhutan. 55. Queen, India-Kashmir. 56. Queen, India-Kashmir. 57. Worker, India-Kashmir. 58. Worker, India-Kashmir. 59. Worker, India- Kashmir. 60. Worker, Pakistan. 61. Male, India-Kashmir. 62. Male, India-Kashmir. 63. Male, Nepal.

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.

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