Bombus

B. griseocollis male mate-searching.

Cullumanobombus ecology and behaviour   HABITAT: High alpine grassland, mountain-meadow, open grassland, and semi-desert.   FOOD-PLANTS: Short to medium tongue-length bumblebees visiting shallow to medium flowers.   NESTING BEHAVIOUR: Nests underground or sometimes on the surface. Pocket-makers only early in colony development.   MATE-SEARCHING BEHAVIOUR: Males of a few species with eyes not enlarged relative to females may patrol circuits of scent marks. But males of many species have enlarged compound eyes and hover or perch before racing after potential mates. B. griseocollis males perch and race, but appear to avoid contact with other males and so are not truly territorial (cf. Williams, 1991).

Subgenus CULLUMANOBOMBUS Vogt
Bombus (Cullumanobombus) Vogt, 1911:57, type-species Apis cullumana Kirby (= Bombus cullumanus (Kirby)) by subsequent designation of Frison, 1927:66
Bremus (Separatobombus) Frison, 1927:64, type-species Bombus separatus Cresson (= Bombus griseocollis (DeGeer)) by original designation
Bremus (Rufocinctobombus) Frison, 1927:78, type-species Bombus rufocinctus Cresson by monotypy
Volucellobombus Skorikov, [1923]:123,149, type-species Bombus volucelloides Gribodo (?= B. melaleucus Handlirsch) by monotypy
Fervidobombus (Rubicundobombus) Skorikov, [1923]:154, type-species Bombus rubicundus Smith by subsequent designation of Sandhouse, 1943:597
Alpigenobombus (Fraternobombus) Skorikov, [1923]:156, type-species Apathus fraternus Smith (= Bombus fraternus (Smith)) by subsequent designation of Frison, 1927:63
Alpigenobombus (Funebribombus) Skorikov, [1923]:157, type-species Bombus funebris Smith by monotypy
Alpigenobombus (Robustobombus) Skorikov, [1923]:157, type-species Bombus robustus Smith by subsequent designation of Sandhouse, 1943:597
Alpigenobombus (Coccineobombus) Skorikov, [1923]:157, type-species Bombus coccineus Friese by subsequent designation of Sandhouse, 1943:539
Cullumanibombus Skorikov, 1938a:145, unjustified emendation
Bombus (Crotchiibombus) Franklin, 1954:51, type-species Bombus crotchii Cresson by original designation
Bombus (Brachycephalibombus) Williams, 1985b:247, type-species Bombus brachycephalus Handlirsch by original designation
Bombus (Dasybombus) Labougle & Ayala, 1985:49, type-species Bombus macgregori Labougle & Ayala by original designation

TAXONOMIC STATUS: For a discussion of why several former subgenera have been synonymised within this subgenus see Williams et al. (2008 [pdf]) .

Part of the bumblebee phylogenetic tree including available Cullumanobombus species from an analysis of DNA sequence data for five genes (Cameron et al. 2007 [pdf]). Values above branches are Bayesian posterior probabilities, values below branches are parsimony bootstrap values. Alternative resolution from parsimony analysis is shown with dotted lines.

rufocinctus-group of species

Bombus (Cu.) rufocinctus Cresson
rufo-cinctus [rufocinctus] Cresson, 1863:106
11 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic, E Nearctic, S Nearctic Regions.

cullumanus-group of species

Bombus (Cu.) semenoviellus Skorikov
semenoviellus Skorikov, 1910b:410
1 name

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Palaearctic Region. This species is reported as spreading westwards in Europe (Smissen & Rasmont, 1999; Pridal & Tkalcu, 2003).

Bombus (Cu.) unicus Morawitz
unicus Morawitz, 1883:235
controversus Skorikov, 1910b:411
2 names

DISTRIBUTION: Palaearctic Region.

Bombus (Cu.) cullumanus (Kirby)
Cullumana (Kirby, 1802:359 [Apis]) examined
serrisquama Morawitz, 1888:224
Silantjewi Morawitz, 1891:132
apollineus Skorikov, 1910b:412
23 names

TAXONOMIC STATUS: Some of these nominal taxa (serrisquama, apollineus) have been treated as separate species. However, aside from differences in colour pattern, they are closely similar in morphology (Panfilov, 1951). Rasmont (1988) has drawn attention to the co-occurrence of the white-banded B. apollineus with the yellow-banded B. serrisquama in northern Iran, apparently without intermediate individuals. But by analogy, it is possible that this colour difference could be the effect of just two alleles at a single locus for pigment (cf. B. melanopygus, see also the comments on B. keriensis). Evidence from COI barcodes is consistent with them being parts of a single species that varies in colour pattern.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Palaearctic Region.

IUCN CONSERVATION STATUS: Preliminary assessment as VULNERABLE (Williams & Osborne, 2009) by criterion A2 (IUCN, 2001, 2008) that it has undergone a a substantial decline in area of occurrence and numbers of records in >50% of the range since 1950. The last record of this species in Britain is 'c. 1941' (BMNH collection) (see declines in British bumble bees).

NOTES on this species in Britain.

brachycephalus-group of species

Bombus (Cu.) brachycephalus Handlirsch
brachycephalus Handlirsch, 1888:244
neotropicus (Frison, 1928:151 [Bremus]) examined
krusemani Asperen de Boer, 1990:1
3 names

TAXONOMIC STATUS: The description of B. krusemani shows that this nominal taxon, known from a single location, diverges slightly in colour pattern from the otherwise widespread, common and variable Central American species, B. brachycephalus. The information available at present for B. krusemani is consistent with the known range of variation within B. brachycephalus (e.g. Labougle, 1990). Until more evidence to the contrary is available from critical studies of patterns of variation, I shall treat them as parts of a single variable species.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: S Nearctic, N Neotropical Regions.

Bombus (Cu.) haueri Handlirsch
Haueri Handlirsch, 1888:234
1 name

MORPHOLOGY: Franklin (1913) and Labougle (1990) believed that this species is closely related to B. crotchii (although Labougle had not examined any males). Surprisingly, Milliron (1973b) placed B. haueri in his 'Dentatus-group', without explanation (B. dentatus is a junior synonym of the Indo-Chinese B. breviceps of the subgenus Alpigenobombus). Possibly Milliron, at least, may have been influenced by Skorikov (1922a), who placed B. haueri in the subgenus Alpigenobombus (as Alpigenobombus (Alpigenobombus) haueri, which he also listed next to Ag. (Ag.) crotchii). However, both sexes of species of the subgenus Alpigenobombus, as it has been accepted recently (Richards, 1968; Williams, 1991 [pdf]), are easily distinguished from any New World bumble bees because they have more teeth on the mandibles.

I have examined the morphology of both sexes and, on the basis of cladistic analysis, have grouped B. haueri with B. brachycephalus (Williams, 1985b [pdf], 1995 [pdf]) and with B. rubicundus (Williams, 1995 [pdf]). Further evidence is awaited.

DISTRIBUTION: S Nearctic Region.

rubicundus-group of species

Bombus (Cu.) rubicundus Smith
[Napensis Spinola in Osculati, 1850:201, published without description]
rubicundus Smith, 1854:400, examined
3 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) handlirschi Friese
handlirschi Friese, 1903:255, examined
1 name

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) coccineus Friese
coccineus Friese, 1903:254, examined
1 name

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) baeri Vachal
Baeri Vachal, 1904:10
1 name

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region, E Neotropical border.

griseocollis-group of species

Bombus (Cu.) crotchii Cresson
Crotchii Cresson, 1878:184
4 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic Region.

Bombus (Cu.) griseocollis (DeGeer)
grifeo-collis [griseocollis] (DeGeer, 1773:576 [Apis])
separatus Cresson, 1863:165
4 names

NOMENCLATURE: The orthography of DeGeer (1773) employs a long 's' (similar to 'f' or 'f'), a common practice of the period. This convention has since changed and recent authors have consistently used 's'.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic, E Nearctic Regions.

Bombus (Cu.) morrisoni Cresson
Morrisoni Cresson, 1878:183
6 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic Region, E Nearctic border.

Bombus (Cu.) macgregori Labougle & Ayala
macgregori Labougle & Ayala, 1985:50, examined
menchuae Asperen de Boer, 1995:47, examined
rasmonti Asperen de Boer, 2007:236, examined
3 names

TAXONOMIC STATUS: B. menchuae was described from a single location and, on the basis of the worker and male I have examined so far, appears to diverge from B. macgregori only in colour pattern. Until more evidence to the contrary is available from critical studies of patterns of variation, I shall treat them as parts of a single variable species.

B. rasmonti was described from three queens from Guatemala (plus one additional older queen) and contrasted with B. melaleucus, 'B. volucelloides' and B. vogti. However, the character states used to differentiate B. rasmonti from these taxa, in particular the larger punctures on the clypeus, the slightly paler wings, and the colour-pattern states such as the entirely black thoracic dorsum, are all shared by a worker tentatively identified as B. macgregori in the BMNH collection. This BMNH worker differs from the original descriptions of both B. macgregori and B. rasmonti in having many white hairs intermixed on the face around the antennal bases and on the vertex. In contrast, the hair of the vertex is described as brownish black for the queens of B. rasmonti (workers remain unknown) and there were apparently only a few of these white hairs for the paratype queens of B. macgregori (the original description notes no differences in the colour of the hairs of the head between castes). Until more evidence to the contrary is available from critical studies of patterns of variation, I shall treat them as parts of a single variable species.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: S Nearctic Region.

Bombus (Cu.) rohweri (Frison)
rohweri (Frison, 1925a:144 [Bremus]) examined
1 name

TAXONOMIC STATUS: B. funebris and B. rohweri have been regarded both as conspecific (Milliron, 1962) and as separate species (Frison, 1925a; Asperen de Boer, 1993a; G. Chavarría, pers. com.). They have been distinguished with reference to subtle morphological characters as well as to the consistently and strongly differing colour patterns. Both Asperen de Boer (1993a) and G. Chavarría (pers. com.) found that they co-occur at some localities without intermediate colour patterns. Further evidence is awaited.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) funebris Smith
funebris Smith, 1854:400, examined
2 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region, S Neotropical border.

robustus-group of species

Bombus (Cu.) fraternus (Smith)
fraternus (Smith, 1854:385 [Apathus]) examined
2 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: E Nearctic Region, W Nearctic border.

Bombus (Cu.) melaleucus Handlirsch
melaleucus Handlirsch, 1888:228, examined
volucelloides Gribodo, 1892:119
melanoleucus Schulz, 1906:267, unjustified emendation
5 names

TAXONOMIC STATUS: Several of these nominal taxa have been treated as separate species.

B. volucelloides is closely similar to B. melaleucus, but has been considered to be a separate species (e.g. Milliron, 1973b; Asperen de Boer, 2007). B. vogti is also similar to B. volucelloides, and these two taxa have been considered both as conspecific (e.g. Franklin, 1913; Labougle, 1990) and as separate species (e.g. Milliron, 1973b; Asperen de Boer, 2007).

There is very little material available of the males in this group from South America, but the males of B. vogti are distinctly different in the morphology of the genitalia. B. nigrothoracicus seems more likely to be conspecific with B. vogti than with B. ecuadorius (see the comments on B. ecuadorius).

Thus B. melaleucus is interpreted here in a broad sense, to include much variation that is not yet well understood. While awaiting more evidence from critical studies of patterns of variation, I treat them initially as parts of a single variable species.

NOMENCLATURE: For this species, the oldest available name of which I am aware is B. melaleucus, which becomes the valid name. The name B. volucelloides has been in most common use for just part of this species. However, it seems premature to conserve B. volucelloides by suppressing B. melaleucus until the taxa are better understood, because the name B. melaleucus might yet be required for a separate species.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: N Neotropical, W Neotropical Regions.

?Bombus (Cu.) vogti Friese
vogti Friese, 1903:254
nigrothoracicus Friese, 1904:188, examined
3 names

TAXONOMIC STATUS: B. vogti is closely similar in morphology to B. robustus, but has been considered to be a separate species (e.g. Milliron, 1973b; Asperen de Boer, 2007).

B. vogti and B. robustus are usually separated using colour. Although B. robustus is variable in colour, the name is applied to individuals with extensive yellow bands, whereas the name B. vogti is used for individuals that lack yellow bands and are often almost completely black. There is very little material available of the males, but the males of B. vogti are at most only subtly different in the morphology of the genitalia. While awaiting more evidence from critical studies of patterns of variation, I treat them initially as separate species.

TAXONOMIC STATUS: See comments on B. melaleucus.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) robustus Smith
robustus Smith, 1854:400, examined
1 name

TAXONOMIC STATUS: See comments on B. hortulanus.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) tucumanus Vachal
tucumanus Vachal, 1904:10
5 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region, E Neotropical border.

Bombus (Cu.) hortulanus Smith
hortulanus Friese, 1904:188, examined
[hortulans Frison, 1925a:155, incorrect subsequent spelling]
3 names

TAXONOMIC STATUS: B. robustus and B. hortulanus have been considered both as conspecific (e.g. Franklin, 1913; Frison, 1925a) and as separate species (e.g. Milliron, 1973b; Asperen de Boer, 2007).

B. robustus and B. hortulanus are morphologically similar. Among the specimens I have seen, individuals that have the sides of gastral terga I-II yellow (B. robustus) also have pubescence extending to the middle or almost to the middle of tergum I, and the males have the space between the inner basal process of the gonostylus and the inner apical process narrower than the apical process. Conversely, individuals with the sides of terga I-II black (B. hortulanus) have at least the middle third of tergum I hairless, and the space between the inner processes of the male gonostylus is wider than the breadth of the apical process.

Until more evidence to the contrary is available from critical studies of patterns of variation, I shall treat them as separate species.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.

Bombus (Cu.) ecuadorius Meunier
Ecuadorius Meunier, 1890:66
?butteli Friese, 1903:254, examined
2 names

TAXONOMIC STATUS: B. butteli is closely similar to B. ecuadorius. They have been considered to be separate species (e.g. Franklin, 1913; Milliron, 1973b), although Franklin conceded that B. butteli (which has grey hairs intermixed on the thoracic dorsum) might be 'only a variety or subspecies' of B. ecuadorius (which has the thoracic dorsum entirely black).

B. ecuadorius females are very rare in collections. For example, Milliron (1973b) had seen only five putative specimens (as opposed to 42 specimens of B. butteli). Of these five specimens, four were females, and just one was a male, which is the same specimen as the holotype of B. nigrothoracicus (see the comments on B. melaleucus). This male is labelled 'Bolivia / ?Peru', whereas the rest of Milliron's B. ecuadorius are from Ecuador, with the exception of one queen from 'Peru' (it carries no further locality data). This putative male of B. ecuadorius also differs from the females in having yellow hairs intermixed on the front and the rear of the thorax. This was not mentioned in the original description of this male (under the name B. nigrothoracicus) by Friese (1904), which Franklin (1913) then used as the sole basis for associating the male with B. ecuadorius.

I favour another possible interpretation. This views the male holotype of B. nigrothoracicus instead as a semi-melanic male of B. melaleucus (the males of B. volucelloides [= B. melaleucus] that I have seen have the thoracic dorsum extensively yellow). This might explain the difference in colour pattern and distribution from other B. ecuadorius. However, a consequence of this interpretation would be that the only remaining known difference between B. ecuadorius and B. butteli would be in colour pattern, because the main morphological justification for regarding them as separate species (the broader apical process of the gonostylus of the putative male B. ecuadorius, now B. melaleucus in the broad sense) would have been removed. Further evidence is awaited.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Neotropical Region.