Bombus

B. terricola queen resting.

Bombus in the strict sense ecology and behaviour   HABITAT: Forest-edge, mountain meadow, and grassland.   FOOD-PLANTS: Short tongue-length bumblebees visiting shallow flowers. They frequently bite holes in corollas and rob deeper flowers. They also provide 'buzz' pollination for tomatoes etc. B. terrestris is especially widely propagated and introduced for the pollination of glasshouse crops.   NESTING BEHAVIOUR: Nests underground. Non-pocket makers. Colonies may be large.   MATE-SEARCHING BEHAVIOUR: Males patrol circuits of scent marks.

Subgenus BOMBUS in the strict sense
[Bremus [Jurine], 1801:164, type-species Apis terrestris Linnaeus = Bombus terrestris (Linnaeus) by subsequent designation of Morice & Durrant, 1915:429, suppressed by ICZN, 1939]
[Bremus Panzer, [1801-1804]:pl.19-21, type-species Apis agrorum Fabricius = Bombus pascuorum (Scopoli) by subsequent designation of Sandhouse, 1943:532, suppressed by ICZN, 1954]
Bombus Latreille, 1802:437, type-species Apis terrestris Linnaeus [cited as Apis terrestris F.] = Bombus terrestris (Linnaeus) by monotypy
Bombus Latreille, 1802:385, type-species Apis terrestris Linnaeus = Bombus terrestris (Linnaeus) by monotypy, redescribed
Bombus (Leucobombus) Dalla Torre, 1880:40, type-species Apis terrestris Linnaeus (= Bombus terrestris (Linnaeus)) by subsequent designation of Sandhouse, 1943:564
Bombus (Terrestribombus) Vogt, 1911:55, type-species Apis terrestris Linnaeus (= Bombus terrestris (Linnaeus)) by subsequent designation of Frison, 1927:67
[Bombellus Zoological Record, 1931:248 ?published without description]

Part of the bumblebee phylogenetic tree including available Bombus s. str. 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. For an alternative Bayesian tree from a larger sample of COI barcodes, see Williams et al. (2012 [pdf]).

Bombus (Bo.) sporadicus Nylander
sporadicus Nylander, 1848:233
czerskianus Vogt, 1911:56, examined
malaisei Bischoff, 1930:4
23 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Palaearctic Region.

Bombus (Bo.) ignitus Smith
ignitus Smith, 1869:207, examined
terminalis Smith, 1873:206, examined, not of Smith in Horne, 1870:193 (= B. festivus Smith)
japonicus Dalla Torre, 1890:139, replacement name for terminalis Smith, 1873:206
15 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Oriental, Japanese Regions.

Bombus (Bo.) terrestris (Linnaeus)
terreftris [terrestris] (Linnaeus, 1758:578 [Apis])
Audax (Harris, 1776:130 [Apis]) not of Harris, 1776:137 (= Anthophora sp.)
xanthopus Kriechbaumer, 1870:157
Dalmatinus Dalla Torre, 1882:26
canariensis Pérez, 1895:191
terrestriformis Vogt, 1911:56, examined
lusitanicus Krüger, 1956:78, examined
africanus Vogt in Krüger, 1956:91, examined
maderensis Erlandsson, 1979:191
112 names

TAXONOMIC STATUS: B. terrestris, B. maderensis, B. canariensis and B. xanthopus have been regarded both as conspecific and as separate species.

Erlandsson (1979) argued that the dark individuals from the Canary Islands, previously placed within B. terrestris by for example Krüger (1954, 1956), are a separate species, B. canariensis. Erlandsson also argued that individuals from the island of Madeira, previously placed within B. terrestris by Bischoff (1937), are a separate species, B. maderensis. In both cases the morphological characters used to support these distinctions are not strongly divergent from the broad variation within B. terrestris in the broad sense. Rasmont (1984) also regarded these three taxa as separate species, but Pekkarinen & Kaarnama (1994) treated them as conspecific.

Estoup et al. (1996) concluded that although mainland populations do not vary significantly among themselves in mitochondrial genes, all island populations studied (from six Mediterranean islands with near-typical B. terrestris in addition to the taxon canariensis) show significant differences from the mainland populations. Rasmont et al. (2008) included several of these as subspecies of B. terrestris. More recent (Bertsch, 2010) and broader (Williams et al., 2012 [pdf]) studies of COI barcodes support the interpretation that they are parts of the broader species B. terrestris.

A study of the taxon xanthopus on Corsica in comparison with B. terrestris in neighbouring Europe by Lecocq et al. (2014) concluded that xanthopus is an endemic Corsican species (although tellingly their COI bGMYC results are consistent with xanthopus being conspecific with terrestris s. l.). However when samples from throughout the known global distribution of B. terrestris were analysed for COI coalescents (using GMYC), including samples from Madeira, the Canary Islands, North Africa, Europe, Russia, Iran, Central Asia, and from as far east as the indigenous eastern limit of the species in Mongolia, then the Corsican 'xanthopus' samples were found to be part of B. terrestris, closely related to other subgroups within that species (Williams et al., 2012 [pdf]).

NOMENCLATURE: The orthography of Linnaeus (1758) 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'.

Day (1979) described how none of the admissable syntypes of A. terrestris Linnaeus is in agreement with the current usage of the name.

To reaffirm the traditional usage of this particularly widely used name, a case was made to ICZN by Løken et al. (1994). This sought an Opinion from ICZN (ICZN, 1996) that set aside, by use of its Plenary Power (ICZN, 1985: Articles 78b, 79), the lectotype designation for A. terrestris by Day from application of the Code (ICZN, 1985), and then designated a neotype (ICZN, 1996: 64) to conserve the traditional usage of the name for even the narrowest concept of the taxon (ICZN, 1985: Article 75).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Palaearctic Region.

INTRODUCTIONS: This species has been introduced into New Zealand (e.g. Gurr, 1957, 1995; Macfarlane & Gurr, 1995) (see the comments on B. hortorum, B. ruderatus, and B. subterraneus), Tasmania (Cardale, 1993; Stout & Goulson, 2000), Brazil (Thorp, 2003), Chile (Torretta et al., 2006), Mexico (Stout & Goulson, 2000; Winter et al., 2006), and Japan (Washitani, 1998; Inoue et al., 2008). It appears that it was also introduced into mainland Australia (New South Wales) without persisting (W. Froggatt in Franklin, 1913). Recently it has spread from Chile to Argentina (Torretta et al., 2006).

NOTES on this species in Britain.

Bombus (Bo.) tunicatus Smith
tunicatus Smith, 1852a:43, examined
vallestris Smith, 1878:8
gilgitensis Cockerell, 1905:223, examined
?manaliensis Kumar & Lall, 2004:236
12 names

TAXONOMIC STATUS: COI barcodes support the interpretation that the taxon gilgitensis is a dark form of the species B. tunicatus (Williams et al., 2012 [pdf]).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Oriental Region.

Bombus (Bo.) affinis Cresson
affinis Cresson, 1863:103
3 names

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: E Nearctic Region. This species has shown a precipitous collapse in its former range and abundance since 1995 (Thorp, 2003; Thorp & Shepherd, 2005; Colla & Packer, 2008).

IUCN CONSERVATION STATUS: Preliminary assessment as CRITICALLY ENDANGERED (Williams & Osborne, 2009) by criterion A2 (IUCN, 2001, 2008) that it is inferred to have undergone a >80% population reduction since 1995, that the causes may not be reversible and may not yet have ceased, based on few records of individuals in the last four years (the species is still being recorded in every year, but in very small numbers: S. Colla, in litt.).

Bombus (Bo.) franklini (Frison)
franklini (Frison, 1921:147 [Bremus]) examined
1 name

TAXONOMIC STATUS: This species has been treated as conspecific with B. occidentalis by Milliron (1971), but has since been shown to be very distinct in morphology by Plowright & Stephen (1980) and Williams (1991 [pdf]), in enzyme mobilities by Scholl, Thorp & Obrecht (1992), and in COI barcodes (Williams et al., 2012 [pdf]).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic Region. B. franklini has one of the narrowest distributions of any bumble bee species world-wide. All recent specimens have been collected within a 60 mile (97 km) radius of Grants Pass, Oregon (Thorp, 1970, 2003, 2005; Thorp et al., 1983). This species has shown dramatic declines in its former range and abundance since 1995 (Thorp, 2003, 2005; Thorp & Shepherd, 2005; IUCN, 2008).

IUCN CONSERVATION STATUS: Preliminary assessment as CRITICALLY ENDANGERED (Williams & Osborne, 2009) by criterion A2 (IUCN, 2001, 2008) that it is inferred to have undergone a >80% population reduction since 1995, that the causes may not be reversible and may not yet have ceased, based on few records of individuals in the last four years. There are suggestions that it may be extinct (Buchmann et al., 2008). The last known record is from 2006 (R. Thorp, in litt.).

Bombus (Bo.) longipennis Friese
longipennis Friese, 1918:83, examined
minshanicola Bischoff, 1936:2, examined
reinigi Tkalcu, 1974b:322, examined
3 names

TAXONOMIC STATUS: Tkalcu (1974) recognised the taxon minshanicola as part of the species B. longipennis from morphology. Bertsch (2010) confirmed that the taxon minshanicola is part of a species separate from B. lucorum from COI barcodes. A broader study of COI barcodes (Williams et al., 2012 [pdf]) confirmed further that the taxon minshanicola is part of B. longipennis, as may be the taxon reinigi. It remains possible that the taxon reinigi might be considered a separate species, depending on which species concept is applied.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Oriental Region.

Bombus (Bo.) lucorum (Linnaeus)
lucorum (Linnaeus, 1761:425 [Apis]), examined
renardi Radoszkowski, 1884:81
?alaiensis Reinig, 1930:107, examined
?mongolicus Krüger, 1954:276, examined
121 names

TAXONOMIC STATUS: COI barcodes (Bertsch, 2010; Williams et al., 2012 [pdf]) support the interpretation that this is a broadly distributed species. However, it remains difficult to distinguish from several related species (especially B. magnus, B. cryptarum, B. longipennis, B. jacobsoni) on the basis of morphology alone (Rasmont et al., 1986; Carolan et al., 2012 [pdf]).

A study of the taxon renardi on Corsica in comparison with B. lucorum in neighbouring Europe by Lecocq et al. (2014) concluded that renardi is an endemic Corsican species (although tellingly their COI bGMYC results show renardi to be conspecific with lucorum s. l.).

NOMENCLATURE: When Day (1979) came to fix the application of A. terrestris Linnaeus (see the comments on B. terrestris), he had no reason to believe that Linnaeus had not described this taxon from the syntype specimen that was subsequently described as the lectotype (= A. cryptarum Fabricius, see Rasmont, 1988:52). This action brought B. lucorum (Linnaeus) into subjective junior synonymy with B. terrestris (Linnaeus).

To reaffirm the traditional usage of B. terrestris and B. lucorum, a case was made to ICZN by Løken et al. (1994). This sought an Opinion from ICZN (ICZN, 1996) that set aside, by use of its Plenary Power (ICZN, 1985: Articles 78b, 79), the lectotype designation for A. terrestris by Day from application of the Code (ICZN, 1985), and then designated a neotype (ICZN, 1996: 64) to conserve the traditional usage of B. terrestris and B. lucorum (ICZN, 1985: Article 75).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Palaearctic, Oriental Regions.

INTRODUCTIONS: This species occurs in Iceland, where it has probably been introduced (Prys-Jones et al., 1981) (see the comments on B. hortorum).

NOTES on this species in Britain.

Bombus (Bo.) jacobsoni Skorikov
jacobsoni Skorikov, 1912:610, examined
2 names

TAXONOMIC STATUS: Bertsch et al. (2010a) concluded that the taxon jacobsoni is part of the species B. cryptarum, although they used a single 'degraded' COI sequence from an old specimen collected in 1929. In contrast, Williams et al. (2012 [pdf]) used sequences from two recent specimens and concluded that B. jacobsoni is a rare, narrowly distributed (its known range is just 260 km across within Jammu and Kashmir, India), but separate species.

DISTRIBUTION: Oriental Region.

Bombus (Bo.) hypocrita Pérez
hypocrita Pérez, 1905:30, examined
sapporoensis Cockerell, 1911:641, examined
15 names

TAXONOMIC STATUS: Tkalcu (1962) mapped the orange-tailed taxon ganjsuensis from North China as part of the species B. hypocrita, but COI barcodes (Williams et al., 2012 [pdf]) support the taxon ganjsuensis as part of the otherwise white-tailed species B. patagiatus (see notes on B. patagiatus).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Japanese, Palaearctic Regions. This species has shown dramatic declines in its former range and abundance in Japan since the introduction there of B. terrestris (Matsumura et al., 2004; Inoue et al., 2008).

Bombus (Bo.) occidentalis Greene
occidentalis Greene, 1858:12, type lost
proximus Cockerell, 1863:98
mckayi Ashmead, 1902:125, examined
9 names

TAXONOMIC STATUS: B. terricola and B. occidentalis have been regarded both as conspecific (e.g. Milliron, 1971; Poole, 1996) and as separate species (e.g. Franklin, 1913 [but see p. 239]; Stephen, 1957; Thorp et al., 1983; Scholl et al., 1990).

In the first major taxonomic review, Franklin (1913:239) wrote of B. terricola and B. occidentalis (among other taxon pairs): "the relationships are evidently very close, the differences, while apparently constant, being so small that it must be entirely a matter of personal opinion whether they should be given full species rank or be considered as only subspecies...[p. 240] If some other worker should reduce [the species to subspecies], the writer could present no very substantial reasons why they should not be so classified." Since then, Franklin's understandable but essentially arbitrary decision has tended to become increasingly set in stone as it has been repeated, despite little in the way of systematic or continent-wide studies to bring further documented evidence to the discussion. Increasing availability of specimens from across North America made justifying recognising B. terricola and B. occidentalis as two separate species on the grounds of differences in colour pattern alone difficult. Franklin (1913:276) distinguished the two by a completely yellow tergum II in B. terricola compared to some black on tergum II in B. occidentalis.

Available specimens appear to show a cline in colour variation between the eastern B. terricola colour pattern and the western B. occidentalis colour pattern. Many specimens from the north west of North America show a reduction in the extent of the yellow bands on gastral terga II and III, with an expansion of the pale pubescence on tergum IV, which might be intermediate or recombinant individuals between the two extreme patterns (worker patterns 3-5 from the left of the colour-pattern diagrams here).

COI barcodes (Bertsch et al., 2010b; Williams et al., 2012 [pdf]) support the interpretation that B. occidentalis is a species separate from B. terricola. There is also evidence for a disjunct northern population, for which the oldest available name is mckayi (Williams et al., 2012 [pdf]).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic Region. This species has shown dramatic declines in range and abundance particularly in the south west of its former range since 1995 (Thorp, 2003; Thorp & Shepherd, 2005).

IUCN CONSERVATION STATUS: Preliminary assessment as ENDANGERED (Williams & Osborne, 2009) by criterion A2 (IUCN, 2001, 2008) that it is inferred to have undergone a >50% population reduction since 1995, that the causes may not be reversible and may not yet have ceased, based on few records of individuals in the last four years, at least in the northern parts of its range.

Bombus (Bo.) terricola Kirby
Terricola Kirby, 1837:273
1 name

TAXONOMIC STATUS: See the comments on B. occidentalis.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: E and W Nearctic Regions. This species has shown dramatic declines in range and abundance particularly in the south of its former range since 1995 (Colla & Packer, 2008).

IUCN CONSERVATION STATUS: Preliminary assessment as ENDANGERED (Williams & Osborne, 2009) by criterion A2 (IUCN, 2001, 2008) that it is inferred to have undergone a >50% population reduction since 1995, that the causes may not be reversible and may not yet have ceased, based on few records of individuals in the last four years, at least in the south-eastern and south-western quarters of its range.

Bombus (Bo.) lantschouensis Vogt
lan-tschóuensis Vogt, 1908:101, examined
vasilievi Skorikov, 1913:172, examined
beickianus Bischoff, 1936:2, examined
pseudosporadicus Bischoff, 1936:2, examined
6 names

TAXONOMIC STATUS: COI barcodes support the interpretation that B. lantschouensis is a separate species (Williams et al., 2012 [pdf]).

DISTRIBUTION: Palaearctic, Oriental Regions.

Bombus (Bo.) minshanensis Bischoff
minshanensis Bischoff, 1936:3, examined
1 name

TAXONOMIC STATUS: COI barcodes support the interpretation that B. minshanensis may be a separate species (Williams et al., 2012 [pdf]), although closely related to B. lantschouensis.

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Oriental Region.

Bombus (Bo.) magnus Vogt
magnus Vogt, 1911:56, examined
flavoscutellaris G & W Trautmann, 1915:96
luteostriatus Krüger, 1954:272, examined
11 names

TAXONOMIC STATUS: B. lucorum and B. magnus have been regarded both as conspecific (Vogt, 1911; Pekkarinen, 1979) and as separate species (Krüger, 1951; Løken, 1973; Tkalcu, 1974; Rasmont, 1984). However, specialists disagreed among themselves on the precise thresholds (along an apparent continuum of morphological variation) for diagnosing them (Williams, 2000 [link]). B. magnus has therefore sometimes been regarded as part of an unresolved complex (Williams et al., 2009) until it becomes possible to recognise and diagnose the species reliably, with the aim of minimising the inevitable but misleading misidentifications.

COI barcodes (Bertsch et al., 2005; Williams et al., 2012 [pdf]) support the interpretation that B. magnus is a species separate from B. lucorum. However, it remains difficult to distinguish from related species reliably on the basis of morphology alone (Rasmont et al., 1986; Carolan et al., 2012 [pdf]).

DISTRIBUTION: Palaearctic Region.

Bombus (Bo.) patagiatus Nylander
patagiatus Nylander, 1848:234, type lost
ganjsuensis Skorikov, 1913:172, examined
brevipilosus Bischoff, 1936:4
22 names

TAXONOMIC STATUS: Tkalcu (1962) mapped the orange-tailed taxon ganjsuensis from North China as part of the species B. hypocrita, but COI barcodes (Williams et al., 2012 [pdf]) support the taxon ganjsuensis as part of the otherwise white-tailed species B. patagiatus (see notes on B. hypocrita).

DISTRIBUTION: Oriental, Palaearctic Regions.

Bombus (Bo.) cryptarum (Fabricius)
cryptarum (Fabricius, 1775:379 [Apis])
albocinctus Smith, 1854:397
modestus Cresson, 1863:99, not of Eversmann, 1852:134 (= B. modestus Eversmann)
moderatus Cresson, 1863:109, replacement name for modestus Cresson, 1863:99
iranicus Krüger, 1954:273
?borochorensis Krüger, 1954:273
?turkestanicus Krüger, 1954:274
?burjaeticus Krüger, 1954:277
florilegus Panfilov, 1956:1334
reinigianus Rasmont, 1984:137
armeniensis Rasmont, 1984:138
52 names

TAXONOMIC STATUS: B. lucorum and B. cryptarum have been regarded both as conspecific (Krüger, 1951; Løken, 1973; Tkalcu, 1974) and as separate species (Rasmont, 1984). What turned out to be B. cryptarum came to people's attention again after an unidentified taxon was found among males of 'B. lucorum' with unexpected labial gland secretions (Kullenberg et al., 1970; Bergstrom et al., 1973). B. cryptarum has sometimes been regarded as part of an unresolved complex (Williams et al., 2009) until it becomes possible to recognise and diagnose the species reliably, with the aim of minimising the inevitable but misleading misidentifications.

COI barcodes (Bertsch et al., 2005; Williams et al., 2012 [pdf]) support the interpretation that B. cryptarum is a species separate from B. lucorum. However, it remains difficult to distinguish from related species reliably on the basis of morphology alone (Rasmont et al., 1986; Carolan et al., 2012 [pdf]).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: Palaearctic, Oriental, Arctic, W Nearctic Regions.