Bombus eriophorus Klug, 1807

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 : 69-70

Bombus eriophorus Klug, 1807

Figs 4 , 14 , 108–114 , 193

Bombus eriophorus Klug, 1807: 265 .

Bombus caucasicus Radoszkowski, 1860: 482 .

Bombus caucasicus var. geogr. [subsp.] tenuicinctus Vogt, 1911: 59.

Bombus caucasicus var. geogr. [subsp.] mixtocinctus Vogt, 1911: 59.

Bombus lapidarius (part) – Reinig 1935: 334. — Williams 1998: 134 (non Linnaeus, 1758: 579).

Vogt (1909: 41, 49) considered the taxon eriophorus s. str. (thoracic dorsum uniformly white) and the taxon caucasicus (thoracic dorsum white with a black band between the wing bases) to be parts of B. lapidarius s. lat. (thorax black or often with anterior and sometimes posterior yellow bands). Subsequently, Vogt (1911: 69) regarded B. caucasicus as a species separate from B. lapidarius and listed the taxon eriophorus s. str. as part of B. caucasicus (even though eriophorus s. lat. is the oldest available name for the species). Reinig (1935: text-fig. 4) considered the taxon eriophorus s. str. and the taxon caucasicus to be parts of B. lapidarius s. lat., showing colour-pattern diagrams with apparently intermediate colour patterns as part of his evidence.

Lecocq et al. (2015) considered that B. caucasicus is likely to be a species separate from B. lapidarius from evidence of COI-coalescent analysis and from differences in composition of cephalic labial gland secretions (CLGS, believed to include sex pheromones). They had no samples of B. eriophorus s. str. but considered it likely to be conspecific with B. caucasicus .

In contrast to Reinig (1935), we agree with Lecocq et al. (2015) that B. eriophorus s. lat. and B. lapidarius s. lat. are separate species from evidence of COI coalescents ( Fig. 10 ), corroborated by morphology.

Our PTP analysis ( Fig. 10 ) of coalescents in the COI gene supports three coalescents for candidate species within the lapidarius- group as identified in the four gene species tree ( Figs 21–22 ): a Caucasusregion candidate species, caucasicus , supported strongly, and two more widespread candidate species within the European taxon lapidarius s. lat., supported relatively weakly. We have been unable to secure fresh samples of the taxon eriophorus s. str. – recent collections in the Caucasus mountains made by three different collectors of bumblebees have been unable to find this taxon.

From morphology, B. eriophorus s. lat. has a colour pattern distinct from B. lapidarius s. lat. for the females with a white-banded thorax. A worker from Azerbaijan in the NHMUK has the black hair of the band between the wing bases much intermixed with white hair, representing a state intermediate between that typical for the taxon eriophorus s. str. and that for the taxon caucasicus . This is slightly darker than the infrasubspecific taxon atava illustrated in Reinig (1935: text-fig. 4-iv). However, both the NHMUK worker and Reinig’s taxon atava with their mixtures of black and white hairs between the wing bases appear to be intermediate in colour pattern between the white unbanded taxon eriophorus s. str. and the white-banded taxon caucasicus , so these two taxa are interpreted provisionally as conspecific as parts of B. eriophorus s. lat.

Diagnosis

Females ( Fig. 4 )

Queens medium-sized body length 17–21 mm, workers 11–15 mm. Can be distinguished in West Asia by their combination of the thoracic dorsum with some pure white hair and the hair of the face and T1–2 black (cf. B. lapidarius , B. sichelii , B. incertus , B. alagesianus ). Workers can be distinguished (cf. B. simillimus ) by the combination of the pale hair of the thoracic dorsum white with T1–2 black and the wings clear.

Males

Body length 12–14 mm. Can be distinguished in West Asia by their combination of thoracic dorsum with extensive yellow hair and T2 usually predominantly black. Genitalia ( Fig. 193 ) with the gonostylus as long as broad, reduced as a rounded flat scale with the inner basal process reduced to a tooth (cf. rufipesgroup, festivus- group, rufofasciatus -group); volsella with the inner distal corner broadly produced but without a narrow hook (cf. rufipes- group, festivus- group, rufofasciatus -group); penis valve head with the recurved inner hook just broader than the narrowest part of the adjacent penis valve shaft (cf. B. lapidarius ); eye unenlarged relative to female eye.

Material examined

Holotype

? RUSSIA • ♀; “monte Caucaso”; “ D. Marshall de Biberstein ” leg.; type of Bombus eriophorus Klug, 1807 not found ( ZIN, ZMHB, ZMUM; possibly lost in a fire with other ZMUM material following the Napoleonic invasion in 1812, A. Antropov pers. com.), but identity not in doubt.

Material sequenced (3 specimens)

GEORGIA • 1 ♀ (queen); Calka ; 41.5891° N, 44.1330° E; 27 May 2011; G. Japoshvili leg.; BOLD seq: 1555A04; AUG: ML175 .

TURKEY • 1 ♀ (worker); Artvin; 41.0641° N, 42.2749° E; H. Hines leg.; BOLD seq: 6877H04; SC: ML420 .

ARMENIA • 1 ♀ (queen); Gegharkunik, Sevan Lake south of Shorzha ; 40.4959° N, 45.2788° E; 7 Jul. 2006; Louda leg.; BOLD seq: 6880A03; MM: ML478 .

Global distribution

(West Asian mountain species) West Asia: TURKEY, GEORGIA, ARMENIA, AZERBAIJAN, RUSSIA: Krasnodar, Stavropol. (AUG, MM, NHMUK, SC.) The species is not known to be common anywhere.

Behaviour

Food-plant choice expected to be generalist but no records. The male mate-searching behaviour is expected to resemble the patrolling of B. lapidarius .

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.