Bombus mendax Gerstaecker

Williams, Paul H., Huang, Jiaxing, Rasmont, Pierre & An, Jiandong, 2016, Early-diverging bumblebees from across the roof of the world: the high-mountain subgenus Mendacibombus revised from species’ gene coalescents and morphology (Hymenoptera, Apidae), Zootaxa 4204 (1), pp. 1-72 : 55-57

12. Bombus mendax Gerstaecker

( Figs 35 , 37, 43, 44, 48 , 67 )

Bomb. <us> mendax Gerstaecker 1869:323 , type-locality citation ‘Königsalpen bei Kreuth (4000 Fuss)’. Lectotype queen by present designation ZISP examined (PR), ‘ Kreuth 4000’ ’ (Alps, Germany). Note 1.

< Bombus mendax > latofasciatus Vogt 1909:50, type-locality citation ‘pyrenaeischen’. Lectotype queen by present designation RMNH examined, ‘ Gèdres’ (Pyrenees, France). Note 2.

[ Bombus mendax ab. atrocaudatus Vogt 1909:50, infrasubspecific.]

[ Bombus mendax var. bizonatus , var. friseanus , var. perfuga Skorikov 1910b:328 -329, infrasubspecific.]

Bombus mendax var. anonymus Friese 1911b:572 , type-locality citation ‘Alpen’. Lectotype queen by present designation MNHU examined, ‘Sierre Alp.’ ( Alps , Switzerland). Note 3.

Mendacibombus mendax (Gerstaecker) ; Skorikov 1923:149.

[ Bombus mendax morpha. nov. subglacialis, ab. nov. flavior, ab. nov. feretypicus, ab. nov. basizonus Pittioni 1937a:121 -122, infrasubspecific.]

[ Bombus (Mendacibombus) mendax f. flavopleuralis, f. quasilatofasciatus Pittioni 1939:103, infrasubspecific.]

< Mendacibombus mendax > ssp. pyrenes Tkalců 1975:173, unnecessary replacement name for latofasciatus Vogt (1909:50). Note 4.

Bombias (Mendacibombus) mendax (Gerstaecker) ; Rasmont 1983:10.

Bombus (Mendacibombus) mendax Gerstaecker ; P.H. Williams 1998:99.

Note 1 ( mendax ). Gerstaecker’s original description of the taxon mendax cites the type locality as ‘Königsalpen bei Kreuth (4000 Fuss)’. The ZISP collection contains material studied by Gerstaecker and includes a queen that agrees with the original description and carries the labels: (1) white, handwritten ‘Kreuth 4000’ ’; (2) white, printed ‘Osnovnaya kollektsiya’; (3) white, handwritten ‘ mendax Gerst. Typ. ’; (4) white with a black border, hand-written ‘ mendax Gerstäck. ’; (5) red, handwritten ‘Type’. No labels were added for this project. This queen, which is complete, is regarded as a syntype and is designated here as the lectotype in order to reduce uncertainty in the identity and application of the name.

Note 2 (latofasciatus). The name latofasciatus was used by Vogt (1909: pages 42, 49, 50) for colour-patternbased taxa within four different species ( B. lucorum , B. mendax , B. sichelii [as B. sicheli ], and B. terrestris ). For the names latofasciatus that were used for parts of B. lucorum and B. terrestris, Vogt explicitly referred to his new names using the term ‘ab.’, so these taxa must remain permanently of infrasubspecific rank ( ICZN 1999: Article 45.6.2). In the case of the name latofasciatus that was used for a part of B. sichelii , he related it to one of three subsets (‘Grade’) within the part of the population with yellow bands known from the Alps and Pyrenees (referred to by him as [subspecies] alticola), thereby implying infrasubspecific rank for this latofasciatus as well. In contrast, Vogt gave no explicit rank to the taxon latofasciatus of B. mendax , but did relate it to ‘Die pyrenaeischen Exemplare’, contrasting them in colour pattern with specimens from the Alps, so this characterisation by geographic distribution and colour-pattern (without a higher subspecific taxon) should be considered to imply subspecific rank as the original intention of the author (ICZN 1 999: Article 45.6.1).

Vogt’s original description of the taxon latofasciatus cites the type locality as ‘pyrenaeischen’. The RMNH collection studied by Vogt contains a queen that agrees with the original description and carries the labels (1) green, printed in red ‘ Gèdres’ ; (2) white, printed ‘ Collectie / C. et O. Vogt / Acq. 1960’; (3) red, printed ‘ Bombus / mendax latofasciatus / Vogt 1909 / ZMAN type HYME.0146.9’; (4) green, printed ‘ Mendacibombus / MD# 1239 det. PHW’; (5) red, printed ‘ LECTOTYPE [female] / Bombus mendax / latofasciatus / Vogt, 1909 / det. PH Williams 2012’; (6) white, printed ‘[female] Bombus / ( Mendacibombus ) / mendax / Gerstaecker / det . PH Williams 2012’. This queen, which is complete, is regarded as one of Vogt’s syntypes and is designated here as the lectotype in order to reduce uncertainty in the identity and application of the name.

Note 3 ( anonymus ). Friese’s original description of the taxon anonymus cites the type locality as ‘ Alpen’ for a queen, worker, and male. The MNHU collection studied by Friese contains a queen that agrees with the original description and carries the labels (1) white, printed ‘Sierre Alp. / 19. 6. 84 / Friese’ ; (2) white, handwritten by Friese ‘ B. mendax . / v. / anonymus / [female] 1909 Friese Fr. Det.’; (3) maroon, printed ‘ Type’; (4) white, printed ‘Zool. Mus. / Berlin’; (5) green, printed ‘ Mendacibombus / MD# 3540 det. PHW’; (6) red, printed ‘ LECTOTYPE [female] / Bombus mendax var. / anonymus / Friese, 1911 / det. PH Williams 2012’; (7) white, printed ‘[female] Bombus / ( Mendacibombus ) / mendax / Gerstaecker / det . PH Williams 2012’. This queen, which is complete, is regarded as one of Friese’s syntypes and is designated here as lectotype in order to reduce uncertainty in the identity and application of the name.

Note 4 (pyrenes). The absence of homonyms for the name latofasciatus Vogt (1909: page 50) available from the same date or older (see note 2) makes Tkalců’s (1975) replacement name unnecessary.

Etymology. The species is named from the Latin mendax for liar, presumably a reference to its close resemblance to other orange-tailed bumblebee species in the mountains of southern Germany.

Taxonomy and variation. The interpretation of this species here is based on DNA and the form of the male genitalia. It agrees with earlier interpretations, which include the substantial variation in the colour pattern of the hair.

This species shows unbanded (taxon mendax s. str.) or narrowly yellow-grey-banded (taxon anonymus MD#3540) colour patterns in the Alps ( Pittioni 1937a), with more broadly yellow-banded colour patterns (taxon latofasciatus MD#1239) further west in the Pyrenees and in Santander in northern Spain ( Vogt 1909; Kruseman 1958: his fig. 6). Our COI tree shows that specimens with these colour patterns can be indistinguishable in the available sequences and are interpreted as conspecific ( Fig. 13 : the unbanded taxon mendax s. str. from the Alps MD#301, the narrow-banded taxon anonymus from the Alps MD#303, and the broad-banded taxon latofasciatus from the Pyrenees MD#3857), as parts of B. mendax s. l..

The distribution of this species is interrupted by two relatively small disjunctions (cf. B. margreiteri ): between the Alps and Pyrenees (> 500 km); and between the Pyrenees and the Picos de Europa in Santander (> 300 km).

The RMNH collection includes at least two queens each with a label printed with ‘Tunkun / Sayan’ and a handwritten label mendax . One is a queen of B. margreiteri (MD#1144), for which the Tunkin mountains are consistent with its known distribution ( Fig. 65 ). However, the other queen (MD#1280) appears from its morphology and colour pattern to be a genuine queen of B. mendax . This specimen has the hair of the thoracic dorsum anteriorly with a narrow pale greyish band with black intermixed, whereas the side of the thorax, the scutellum, T2, and the foreleg and midleg basitarsi are predominantly black, like many B. mendax from the Alps ( Pittioni 1937a). Without COI data we cannot at present make a definitive determination. Therefore the apparent Tunkin location is likely to be the result of mislabeling and this record is not included on the map for B. mendax (mislabelling is not unknown: see the note on the holotype of B. superbus ).

Diagnostic description. Wings nearly clear. Female hair colour pattern: generally black, but with yellow hair varying from completely absent from the entire body to present over most of the face and in a small patch on the vertex of the head, a transverse band anteriorly on the thoracic dorsum and extending laterally and ventrally almost to the midleg base, in a transverse band posteriorly on the thoracic dorsum (scutellum; so the thoracic dorsum between the wing bases has the hair entirely black, sometimes the yellow bands with black hairs intermixed), often on T1, sometimes on T2 pale in the anterior half, always orange hair on T3 as a posterior fringe and throughout T4‒6, except T6 medially with black hair. Hindleg tibia with the corbicular fringes extensively orange. Female morphology: labrum with the basal depression broad, the transverse ridge in the median third narrowed but not interrupted or subsiding, or subsiding only slightly, with only a few scattered punctures, the lateral tubercles with few punctures. Male morphology: genitalia ( Fig. 35 ) with the volsella distally rounded (finger-shaped) and curled back dorsally but not anteriorly; volsella at its broadest near the midpoint of its length, the dorsal surface just distal to this point without a raised curved ridge just inside the inner margin. Gonostylus distally thick, rounded in section, and finger-like; gonostylus with the inner distal corner almost a right angle from both the inner and dorsal aspects. Penis-valve inner shoulder located at Ĺ 0.5× the length of the penis valve from the distal end to the broadest point of the spatha; penis valve proximal to the outer shoulder> 2× as broad as the penis-valve head; penis-valve head dorso-ventrally compressed.

Material examined. 383 queens 1249 workers 142 males (plus 6 with sex/caste undetermined), from Andorra, Austria, France, Germany, Italy, Spain, and Switzerland ( Fig. 67 : AA, AS, ENAM, LC, MNHN, MNHU, NHM, PW, RBIN, RMNH, UMONS, ZIUB, ZSM; specimens in the UMONS database have not had individual MD# labels added), with 7 specimens sequenced (interpretable sequences listed in Figs. 11–13 ).

Habitat and distribution. Flower-rich alpine and subalpine grassland, at elevations 655‒(2111)‒ 3098 m a.s.l.. A species distributed in three principal disjunct centres, in the Alps, the Pyrenees, and the Cantabrian mountains. There is no overlap in distribution with any other Mendacibombus species. Distribution maps are available for France ( Rasmont 1988), Spain ( Ornosa & Torres 2010), and Europe ( Rasmont & Iserbyt 2012; Rasmont et al. 2015).

So far, this is the only species of the subgenus Mendacibombus to have been assessed for Red List threat status using the IUCN criteria (2001). Cederberg et al. (2013) listed it as ‘Near Threatened’ because its known area of occupancy (AOO) is small (2,236 km ²), the species’ distribution is considered severely fragmented, and they believe that the number of individuals has been declining due to climate change, putting the species close to qualifying for the IUCN category ‘Vulnerable’ (Criterion B2). Rasmont et al. (2015) use climate-change models to assess this species as having a high risk of extinction from climate change by 2100.

Food plants. Pittioni (1937a), Aichhorn (1976), Haas (1976), Rasmont (1988), von Hagen & Aichhorn (2003).

Behaviour. Aichhorn (1976), Haas (1976), von Hagen & Aichhorn (2003).

Figures

FIGURE 13. Assigning names to species from an estimate of phylogeny for 130 COI sequences of the subgenus Mendacibombus. Based on a BEAST analysis of the 30 unique haplotypes (Fig. 11), with the remaining sequences interpolated back into the tree with 0 branch lengths from their matching samples (where a sequence matches more than one longer sequence within a species in the Collapse results, it is added after the first matching sequence, with the addition of the two short-sequence yellow unbanded specimens from Pakistan, MD # 4058, 4059). The sequence labels follow the format used in Figs 11, 12. Lineages accepted as species from the GMYC models (Fig. 11) are shown as thick branches, the most recent common ancestors of each species are shown with a black spot, and branches within species are shown as thin branches. Asterisks mark samples used as informal proxies for the type specimens of each of the taxon names (Table 1). The proxy sample for the type specimen for the oldest available name (the valid name) for each species (from Fig. 11) is marked in bold. The interpretations of the species with their valid names are shown in grey to the right.

FIGURES 24 ‒ 35. Morphology of the male genitalia for species of the subgenus Mendacibombus from the dorsal aspect, anterior to the left of the image, posterior to the right: 24, B. superbus, China MD # 339; 25, B. waltoni, China MD # 216; 26, B. convexus, China MD # 215; 27, B. makarjini, Kazakhstan MD # 1240; 28, B. marussinus, Pakistan MD # 408; 29, B. avinoviellus, India MD # 404; 30, B. himalayanus, India MD # 426; 31, B. turkestanicus, China MD # 351; 32, B. defector, Kyrgyzstan MD # 367; 33, B. margreiteri, China MD # 294; 34, B. handlirschianus, Russia MD # 835; 35, B. mendax, Spain MD # 689.

FIGURES 36 ‒ 55. Morphology of parts of the male genitalia from the dorsal aspect of the left side, anterior to the left of the image, posterior to the right, white bars indicating morphological characters referred to in the key to males: 36, B. waltoni; 37, B. mendax; 38, B. superbus; 39, B. convexus; 40, B. waltoni; 41, B. convexus; 42, B. defector; 43, B. mendax; 44, B. mendax; 45, B. turkestanicus; 46, B. avinoviellus; 47, B. mendax; 48, B. mendax; 49, B. makarjini; 50, B. handlirschianus; 51, B. himalayanus; 52, B. turkestanicus; 53, B. himalayanus; 54, B. himalayanus; 55, B. marussinus.

FIGURES 56 ‒ 67. Maps of the global distributions of species of the subgenus Mendacibombus from the material examined, with grey spots for specimen records and black spots for the samples with COI sequences (each species is unknown from regions outside the map boundaries shown); grey crosses for records of all species of Mendacibombus combined. Relief map with hill shading, Cartesian orthonormal projection, grey lines show borders to national administration according to UN maps, north at the top of the map. Image created in ArcGIS using World _ Shaded _ Relief basemap © 2014 Esri.

FIGURES 11 ‒ 12. Recognising species from an estimate of phylogeny for 30 unique COI haplotypes of the subgenus Mendacibombus by BEAST, using GMYC models and the PTP procedure. From the GMYC models (11), the single threshold T is shown by the vertical grey bar so that the intersecting lineages are interpreted as indicating 12 separate species (black spots at coalescent nodes; outgroups not shown). Values below the nodes of the maximum clade-credibility tree are Bayesian posterior probabilities showing branch support (groups with values <0.8 are considered unreliable) from the BEAST analysis with two billion MCMC generations and a 1 % burn-in. The x - scale axis is calibrated in substitutions per nucleotide site. From the PTP procedure (12), the Bayesian PTP solution with highest support also indicates 12 species. Values above the nodes are PTP Bayesian support values that all daughter haplotypes are parts of a single species; values below the nodes are Bayesian posterior probabilities showing branch support. The scale bar is calibrated in substitutions per nucleotide site. Each unique haplotype is represented by one of the longest available sample sequences, labelled with: the sequence length in number of base pairs, a taxon name or name for an unpublished colour pattern (light / dark / yellow / white / pale), and then a code that consists of a specimen identifier (MD #) from the project database and (after the hyphen) a sample identifier from BOLD or from GenBank, followed with its geographic origin.