Bombus semenovianus (Skorikov, 1914)

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 : 75-76

Bombus semenovianus (Skorikov, 1914)

Figs 5 , 15 , 125–128 , 196

Lapidariobombus semenovianus Skorikov, 1914a: 127 .

Bombus lapidarius subsp. problematicus Bischoff, 1935: 255 .

Our PTP analysis ( Fig. 10 ) of coalescents in the COI gene supports three coalescents for candidate species within the sichelii- group as identified in the four gene species tree ( Figs 21–22 ): B. incertus , B. sichelii s. lat., and the Himalayan B. semenovianus .

From morphology, B. semenovianus is supported by its distinctive colour pattern with the thoracic dorsum entirely yellow (known otherwise only for some males of B. eriophorus from the Caucasus),

by its distinctive form of the male genitalia (see the Diagnosis), and by its slightly enlarged male eye relative to the female eye ( Williams, 1991).

Diagnosis

Females ( Fig. 5 )

Queens medium-sized body length 17–21 mm, workers 11–15 mm. Can be distinguished by the hair on the thoracic dorsum being uniformly bright yellow (cf. B. keriensis , B. separandus , etc.).

Males

Body length 12–16 mm. Can be distinguished by the unique combination of having the eyes slightly enlarged relative to female eye and the hair of the thoracic dorsum being uniformly bright yellow (cf. B. eriophorus , B. qilianensis ). Genitalia ( Fig. 196 ) with the gonostylus as long as broad, reduced as a rounded flat scale with the inner basal process reduced to a tooth (cf. rufipes- group, festivus- group, rufofasciatus -group); volsella with the inner distal corner broadly produced but without a narrow hook (cf. rufipes- group, festivus- group, rufofasciatus -group); eye slightly enlarged relative to female eye.

Material examined

Syntype

INDIA • ♀ (queen), syntype of Lapidariobombus semenovianus Skorikov, 1914 ( Williams 1991) ; Kashmir, Ladakh, Stakmo pass; 13 Jul. 1912; G. Jakobson leg.; ZIN (examined PW) .

Material sequenced (5 specimens)

PAKISTAN • 1 ♀ (worker); Karakorum , Holshal; 36.1962° N, 74.9496° E; BOLD seq: 1552E07; SEHU: ML187 • 1 ♀ (queen); Chitral , Tirich Valley; 36.3150° N, 71.9824° E; 27 Jul. 1984; W. Budenburg leg.; BOLD seq: 6877G11; PW: ML416 • 1 ♂; Ganokh ; 34.7552° N, 76.2808° E; 4 Sep. 2017; S. Jaffar leg.; BOLD seq: 1555E10; UAP: ML258 • 1 ♂; upper Memosh ; 34.7093° N, 76.1208° E; 5 Sep. 2017; S. Jaffar leg.; BOLD seq: 1555E11; UAP: ML259 • 1 ♂; same collection data as for preceding; BOLD seq: 6877H06; UAP: ML422 .

Global distribution

(West Himalayan mountain species) Himalaya: AFGHANISTAN, PAKISTAN, INDIA: Kashmir. (NHMUK, PW, SEHU, UAP, ZIN, ZSM.) The species is locally common.

Behaviour

Food-plant generalists ( Williams 1991). Male mate-searching behaviour is poorly known ( Williams 1991).

Figures

Figs 1‒6. Individuals of the subgenus Melanobombus von Dalla Torre, 1880 (with photo credits). 1. Bombus eximius Smith, 1852, queen, Thailand (CT). 2. B. simillimus Smith, 1852, worker, India- Kashmir (RR). 3. B. prshewalskyi Morawitz, 1880, worker, China-Gansu (PW). 4. B. eriophorus Klug, 1807, queen, Georgia (I. Popov). 5. B. semenovianus (Skorikov, 1914), male, India-Kashmir (PW). 6. B. ladakhensis Richards, 1928, male, China-Gansu (PW). Some images reversed.

Figs 14‒16. Maps of sequenced samples as in Figs 12–13. 14. The tanguticus-group and the lapidarius- group. 15. The sichelii-group. 16. The keriensis-group.

Figs 103–138. 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 tanguticus-group. 103. Worker, China-Qinghai. 104. Worker, China-Qinghai. 105. Queen, China-Qinghai. 106. Queen, China-Xizang. 107. Queen, India-Kashmir. The lapidarius-group. 108. Queen, Russia-North Ossetia. 109. Worker, Azerbaijan. 110. Queen, Georgia. 111. Male, Russia-North Ossetia. 112. Male, Russia-North Ossetia. 113. Male, Russia-North Ossetia. 114. Male, Turkey. 115. Queen, Morocco. 116. Queen, Spain. 117. Queen, Spain. 118. Queen, UK. 119. Male, Spain. 120. Male, Spain. 121. Male, UK. 122. Male, UK. The sichelii-group. 123. Queen, Iran. 124. Male, Iran. 125. Queen, India-Kashmir. 126. Queen, India- Kashmir. 127. Male, India-Kashmir. 128. Male, India-Kashmir. 129. Queen, Iran. 130. Queen, Russia- Sakha. 131. Queen, China-Sichuan. 132. Worker, China-Sichuan. 133. Queen, Mongolia. 134. Worker, Mongolia. 135. Queen, Spain. 136. Worker, Austria. 137. Male, Turkey. 138. Male, Mongolia.

Figs 190‒198. 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. 190. Bombus friseanus Skorikov, 1933, China-Yunnan. 191. B pyrosoma Morawitz, 1890, China- Beijing. 192. B. formosellus (Frison, 1934), China-Taiwan. 193. B. eriophorus Klug, 1807, Russia- North Ossetia. 194. B. lapidarius (Linnaeus, 1758), UK. 195. B. incertus Morawitz, 1881, Turkey. 196. B. semenoviaus (Skorikov, 1914), India-Kashmir. 197. B. sichelii Radoszkowski, 1859, Austria. 198. B. ladakhensis Richards, 1928, China-Sichuan. 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.

Fig. 21. A sample of 10 000 species trees from among 100 million trees for species of the subgenus Melanobombus von Dalla Torre, 1880 reconstructed with *BEAST from gene trees for the COI, 16S, opsin and PEPCK genes, displayed in green using Densitree, with the summary ‘root canal’ superimposed as a thick blue line. The outgroup B. nobilis Friese, 1905 is shown.

Fig. 22. Most likely dated phylogenetic (ultrametric) tree for the species of the subgenus Melanobombus reconstructed von Dalla Torre, 1880 with *BEAST from trees for four genes (COI, 16S, PEPCK, opsin) with B. nobilis Friese, 1905 as the outgroup (not shown), estimated as the maximum-clade-credibility tree among a sample of 10 000 species trees with a 1% burn-in out of 100 million MCMC trees. Values above the nodes are Bayesian posterior probabilities showing support for groups. Values below the nodes are estimated dates of divergence in Ma (millions of years before the present) calibrated from a molecular estimate for the date of crown divergence within the subgenus Melanobombus. Grey bars show the 95% confidence limits on the estimated dates of divergence. Species groups discussed in the text are labelled in circles: rp = rufipes-group; fs = festivus-group; rf = rufofasciatus-group; tg = tanguticus-group; la = lapidarius-group; si = sichelii-group; and ke = keriensis-group.