View source for Bumblebee

{{short description|Genus of insect}}
{{other uses}}
{{redirect|Bombus|other uses|Bombus (disambiguation)}}
{{good article}}
{{pp-semi-indef}}
{{Use dmy dates|date=August 2020}}
{{Automatic taxobox
|taxon          =Bombus
|image          =Bombus lapidarius - Melilotus officinalis - Tallinn.jpg
|image_caption  =Red-tailed bumblebee (''[[Bombus lapidarius]]'')
|fossil_range   ={{fossil_range|Eocene|Present}}
|authority=[[Pierre André Latreille|Latreille]], 1802
|diversity      =>&nbsp;250 species and subspecies
|diversity_link =List of bumblebee species
|range_map=Bombus distribution.jpg
|range_map_caption={{ubl|Natural distribution shown in red.|Introductions to New Zealand, spread to Tasmania not shown}}
}}

A '''bumblebee''' (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the [[genus]] '''''Bombus''''', part of [[Apidae]], one of the [[bee]] families. This genus is the only [[Extant taxon|extant]] group in the tribe [[Bombini]], though a few extinct related genera (e.g., ''[[Calyptapis]]'') are known from [[fossil]]s. They are found primarily in the [[Northern Hemisphere]], although they are also found in South America, where a few lowland tropical species have been identified. European bumblebees have also been introduced to New Zealand and [[Tasmania]]. Female bumblebees can sting repeatedly, but generally ignore humans and other animals.

Most bumblebees are [[eusociality|eusocial]] insects that form [[colony (biology)|colonies]] with a single queen. The colonies are smaller than those of [[honey bee]]s, growing to as few as 50 individuals in a nest. [[Psithyrus|Cuckoo bumblebees]] are [[brood parasite|brood parasitic]] and do not make nests or form colonies; their queens aggressively invade the nests of other bumblebee species, kill the resident queens and then lay their own eggs, which are cared for by the resident workers. Cuckoo bumblebees were previously classified as a separate genus, but are now usually treated as members of ''Bombus''.

Bumblebees have round bodies covered in soft hair (long branched [[seta]]e) called 'pile', making them appear and feel fuzzy. They have [[aposematism|aposematic (warning) coloration]], often consisting of contrasting bands of colour, and different species of bumblebee in a region often resemble each other in mutually protective [[Müllerian mimicry]]. Harmless insects such as [[Hoverfly|hoverflies]] often derive protection from resembling bumblebees, in [[Batesian mimicry]], and may be confused with them. Nest-making bumblebees can be distinguished from similarly large, fuzzy cuckoo bumblebees by the form of the female hind leg. In nesting bumblebees, it is modified to form a [[pollen basket]], a bare shiny area surrounded by a fringe of hairs used to transport [[pollen]], whereas in cuckoo bumblebees, the hind leg is hairy all around, and they never carry pollen.

Like their relatives the honeybees, bumblebees feed on [[nectar]], using their long hairy tongues to lap up the liquid; the [[proboscis]] is folded under the head during flight. Bumblebees gather nectar to add to the stores in the nest, and pollen to feed their young. They forage using colour and spatial relationships to identify flowers to feed from. Some bumblebees [[nectar robbing|steal nectar]], making a hole near the base of a flower to access the nectar while avoiding pollen transfer. Bumblebees are important agricultural [[pollinator]]s, so [[Pollinator decline|their decline]] in Europe, North America, and Asia is a cause for concern. The decline has been caused by [[habitat destruction|habitat loss]], the [[mechanisation]] of agriculture, and [[pesticide]]s.

== Etymology ==

[[File:Mrs tittlemouse.jpg|thumb|upright|[[Beatrix Potter]]'s 1910 story ''[[The Tale of Mrs. Tittlemouse]]'' features a "bumble bee" called Babbity Bumble.<ref name="Jones 2010"/>]]

The English name '''bumblebee''' combines ''bumble'', meaning to buzz or hum, with ''bee'', both words imitative of the insect's sound.<ref name="OED"/> The [[Genus|generic name]] '''''Bombus''''', introduced by [[Pierre André Latreille]] in 1802, derives from the Latin ''bombus'' ("buzzing" or "booming"), itself from Ancient Greek ''βόμβος'' (''bómbos'').<ref>{{cite book |last=Latreille |first=Pierre André |author-link=Pierre André Latreille |year=1802 |title=Histoire naturelle, générale et particulière des crustacés et des insectes |location=Paris |publisher=Dufart |url=https://www.biodiversitylibrary.org/bibliography/15764}}</ref>

Charles Darwin referred to bumblebees as "humble-bees" in his 1859 book ''[[On the Origin of Species]]'', emphasising their importance in pollinating clovers and other wildflowers.<ref>{{cite book |last=Darwin |first=Charles |year=1859 |chapter=3. Struggle for Existence |title=[[On the Origin of Species by Means of Natural Selection]] |location=London |publisher=[[John Murray (publishing house)|John Murray]] |chapter-url=https://www.gutenberg.org/cache/epub/1228/pg1228.txt}}</ref> The term ''humblebee'' remained in use through the nineteenth century, but was gradually replaced by ''bumblebee'' in both scientific and common language during the twentieth century.<ref name="OED">{{cite dictionary |title=Humble-bee, n. Meanings, etymology and more &#124; Oxford English Dictionary |entry=humblebee |dictionary=[[Oxford English Dictionary]] |chapter-url=https://www.oed.com/dictionary/humble-bee_n |access-date=22 October 2025}}</ref><ref name="Jones 2010">{{cite news |last=Jones |first=Richard |date=1 August 2010 |title=How the humblebee became the bumblebee |newspaper=[[The Guardian]] |location=London |url=https://www.theguardian.com/environment/2010/aug/01/humblebee-bumblebee-darwin}}</ref>

== Evolution ==

=== Phylogeny ===

The tribe '''Bombini''' (bumblebees) is one of four lineages of corbiculate bees in the [[Apidae]]. It is distinguished by having pollen baskets (corbiculae) on their hind legs. The other three are the [[Apini]] (honeybees), [[Euglossini]] (orchid bees), and [[Meliponini]] (stingless bees). Together they form a [[monophyletic]] group.<ref name="Cardinal-2011">{{cite journal |last1=Cardinal |first1=Sophie |last2=Danforth |first2=Bryan N. |date=June 2011 |title=The Antiquity and Evolutionary History of Social Behavior in Bees |journal=[[PLOS One]] |volume=6 |issue=6 |article-number=e21086 |doi=10.1371/journal.pone.0021086 |doi-access=free |pmc=3113908 |pmid=21695157 |bibcode=2011PLoSO...621086C }}</ref>

Early analyses of morphology and behaviour suggested that complex [[eusociality]] evolved twice within the corbiculate bees, once in the ancestor of the Apini and once in the Meliponini. Molecular and morphological data indicate that the primitively eusocial Bombini are, despite appearances, closely related to the Meliponini, while the Apini and Euglossini form a separate branch. Cardinal and Danforth (2011) described this dual-origin model as consistent with earlier evidence from social and anatomical traits.<ref name="Cardinal-2011"/>

{{clade|style=font-size:100%;line-height:100%
|label1=[[Corbiculata]]
|1={{clade
   |1={{clade
      |label1=''eusocial''
      |1=[[Apini]] (honeybees)
      |2=[[Euglossini]] (orchid bees)
      }}
   |2={{clade
      |1='''[[Bombini]]''' (bumblebees)
      |label2=''eusocial''
      |2=[[Meliponini]] (stingless bees)
      }}
   }}
}}

More recent phylogenomic studies based on the mRNA expression profile from more than 3,600 genes support instead a single origin of eusociality within the corbiculate bees. Romiguier ''et al.'' (2015) found that the Bombini, Meliponini, and Apini form a single clade, with Euglossini as their sister group, implying that advanced social organisation arose once in the common ancestor of these three tribes.<ref>{{cite journal |last1=Romiguier |first1=J. |last2=Cameron |first2=S.A. |last3=Woodard |first3=S.H. |last4=Fischman |first4=B.J. |last5=Keller |first5=L. |last6=Praz |first6=C.J. |year=2015 |title=Phylogenomics controlling for base compositional bias reveals a single origin of eusociality in corbiculate bees |journal=[[Molecular Biology and Evolution]] |volume=33 |issue=3 |pages=670–678 |doi=10.1093/molbev/msv258 |pmid=26576851 |doi-access=free}}</ref>

Revisiting the "corbiculate controversy",<ref name="Porto 2021"/> on the mismatch between morphological and molecular analyses in 2021, Diego Sasso Porto and Eduardo A. B. Almeida find that morphological analysis still suggests that Bombini are sister to a clade containing Apini and Meliponini, as shown in the phylogenetic tree. They propose "a more conciliatory"<ref name="Porto 2021"/> scenario involving "a diversification followed by several extinctions"<ref name="Porto 2021"/> so that Meliponini and Bombini shared "few [[apomorphic]] changes",<ref name="Porto 2021"/> while the similarities between Meliponini and Apini could be [[convergent evolution]] caused by "similar biology or similar eusocial behaviors".<ref name="Porto 2021">{{cite journal |last1=Porto |first1=Diego Sasso |last2=Almeida |first2=Eduardo A. B. |title=Corbiculate Bees (Hymenoptera: Apidae): Exploring the Limits of Morphological Data to Solve a Hard Phylogenetic Problem |journal=[[Insect Systematics and Diversity]] |volume=5 |issue=3 |date=1 May 2021 |article-number=2 |doi=10.1093/isd/ixab008 |doi-access=free}}</ref>

{{clade
|label1=[[Corbiculata]]
|1={{clade
   |1=[[Euglossini]] (orchid bees)
   |2={{clade
      |1=[[Bombini]] (bumblebees)
      |label2=''eusocial''
      |2={{clade
         |1=[[Apini]] (honeybees)
         |2=[[Meliponini]] (stingless bees)
         }}
      }}
   }}
}}

The earliest divergence estimates suggest that the Bombini originated between 25 and 40 million years ago, whereas the Bombini–Meliponini clade dates to roughly 80–95 million years ago, around the time the corbiculate group as a whole diversified.<ref name="Cardinal-2011"/>

=== Fossil record ===

[[File:Dehon et al 2019 Zookeys Fig2-D Bombus (Cullumanobombus) pristinus.jpg|thumb|upright|''[[Bombus pristinus]]'' described in 1867]]

[[File:Dehon et al 2019 Zookeys Fig1-C Calyptapis florissantensis.jpg|thumb|upright|''[[Calyptapis florissantensis]]'', Eocene [[Florissant Formation]] ]]

Fossil evidence of Bombini is limited. By 2019, about 14 potential fossil species had been described.<ref name="Dehon-2019">{{cite journal |last1=Dehon |first1=M. |last2=Engel |first2=M.S. |last3=Gérard |first3=M. |last4=Aytekin |first4=A.M. |last5=Ghisbain |first5=G. |last6=Williams |first6=P.H. |last7=Rasmont |first7=P. |last8=Michez |first8=D. |year=2019 |title=Morphometric analysis of fossil bumble bees (Hymenoptera, Apidae, Bombini) reveals their taxonomic affinities |journal=ZooKeys |issue=891 |pages=71–118 |pmid=31802973 |doi=10.3897/zookeys.891.36027 |pmc=6882928 |bibcode=2019ZooK..891...71D |doi-access=free}}</ref> The oldest known relatives include ''[[Calyptapis florissantensis]]'' from the Late Eocene [[Florissant Formation]] (United States) and ''[[Oligobombus cuspidatus]]'' from the [[Bembridge Marls]] (Isle of Wight).<ref>{{cite journal |last1=Antropov |first1=A.V. |year=2014 |title=The wasps, bees and ants (Insecta: Vespida=Hymenoptera) from the Insect Limestone (Late Eocene) of the Isle of Wight |journal=Earth and Environmental Science Transactions of the Royal Society of Edinburgh |volume=104 |issue=3–4 |pages=335–446 |doi=10.1017/S1755691014000103}}</ref>

Several Oligocene and Miocene species have been assigned to modern subgenera, including ''Bombus ([[Mendacibombus]]) beskonakensis'' and ''B. ([[Paraelectrobombus]]) patriciae'' from Turkey, ''[[Bombus randeckensis|B. randeckensis]]'' from Germany, ''[[Bombus cerdanyensis|B. cerdanyensis]]'' from Spain, and ''[[Bombus trophonius|B. trophonius]]'' from the Czech Republic.<ref name="Wappler-2012">{{cite journal |last1=Wappler |first1=T. |last2=De Meulemeester |first2=T. |last3=Aytekin |first3=A.M. |last4=Michez |first4=D. |last5=Engel |first5=M.S. |year=2012 |title=Geometric morphometric analysis of a new Miocene bumble bee from the Randeck Maar of southwestern Germany (Hymenoptera: Apidae) |journal=Systematic Entomology |volume=37 |issue=4 |pages=784–792 |doi=10.1111/j.1365-3113.2012.00642.x |bibcode=2012SysEn..37..784W }}</ref><ref name="Prokop-2017">{{cite journal |last1=Prokop |first1=J. |last2=Dehon |first2=M. |last3=Michez |first3=D. |last4=Engel |first4=M.S. |year=2017 |title=An Early Miocene bumble bee from northern Bohemia (Hymenoptera, Apidae) |journal=ZooKeys |issue=710 |pages=43–63 |doi=10.3897/zookeys.710.14714 |pmid=29118643 |pmc=5674177 |bibcode=2017ZooK..710...43P |doi-access=free}}</ref><ref name="Dehon-2014">{{cite journal |last1=Dehon |first1=M. |last2=Michez |first2=D. |last3=Nel |first3=A. |last4=Engel |first4=M.S. |last5=De Meulemeester |first5=T. |year=2014 |title=Wing shape of four new bee fossils (Hymenoptera: Anthophila) provides insights to bee evolution |journal=PLOS ONE |volume=9 |issue=10 |article-number=e108865 |doi=10.1371/journal.pone.0108865 |pmid=25354170 |pmc=4212905 |bibcode=2014PLoSO...9j8865D |doi-access=free}}</ref>

These fossils indicate that the major subgenera of ''[[Bombus]]'' were already differentiated by the Miocene and that diversification of the tribe was well underway by the Oligocene.<ref name="Dehon-2019" />

== Taxonomy ==

{{further|List of bumblebee species}}

The genus ''Bombus'', the only one extant genus in the tribe Bombini, comprises over 250 species;<ref>{{cite journal |last=Williams |first=Paul H. |year=1998 |title=An annotated checklist of bumble bees with an analysis of patterns of description |journal=Bulletin of the Natural History Museum, Entomology Series |volume=67 |pages=79–152 |url=http://www.nhm.ac.uk/research-curation/projects/bombus/subgenericlist.html |access-date=30 May 2012}}</ref> for an overview of the differences between bumblebees and other bees and wasps, see [[characteristics of common wasps and bees]]. The genus has been divided variously into up to 49 subgenera, a degree of complexity criticised by Williams (2008).<ref name="Williams-2008">{{cite journal |last1=Williams |first1=Paul |last2=Cameron |first2=Sydney A. |last3=Hines |first3=Heather M. |last4=Cederberg |first4=Bjorn |last5=Rasmont |first5=Pierre |year=2008 |title=A simplified subgeneric classification of the bumblebees (genus ''Bombus'') |journal=Apidologie |doi=10.1051/apido:2007052 |s2cid=3489618 |volume=39 |pages=46–74 |url=https://hal.science/hal-00891940 }}</ref><ref>{{cite journal |last1=Cameron |first1=S. A. |last2=Hines |first2=H. M. |last3=Williams |first3=P. H. |title=A comprehensive phylogeny of the bumble bees (Bombus) |journal=Biological Journal of the Linnean Society |volume=91 |issue=1 |date=2007 |doi=10.1111/j.1095-8312.2007.00784.x |doi-access=free |pages=161–188 |url=http://www.bio-nica.info/biblioteca/Cameron2007BumbleBees.pdf |access-date=14 October 2025}}</ref> The cuckoo bumblebees ''Psithyrus'' have sometimes been treated as a separate genus but are now considered to be part of ''Bombus''.<ref name="Williams-2008"/>

{{clade|style=font-size:85%;line-height:85%
|label1= '''''Bombus''' (genus)''
|1={{clade
    |1={{clade
      |1=''[[Mendacibombus]]'', 12 species
      |2=''[[Bombias]]'', 3 species
      |3={{clade
           |1=''[[Kallobombus]]'', 1 species
           |label2=long-faced
           |2={{clade
                |1=''[[Orientalibombus]]'', 3 species
                |2=''[[Subterraneobombus]]'', 10 species
                |3={{clade
                      |1=''[[Megabombus]]'', 22 species
                      |2={{clade
                         |1=''[[Thoracobombus]]'', 50 species
                         |label2=social|sublabel2=parasites
                         |2=''[[Psithyrus]]'', 30 species
                         }}
                   }}
              }}
           |label3=short-faced
           |3={{clade
               |1={{clade
                  |1=''[[Pyrobombus]]'', 50 species
                  |2={{clade
                     |1=''[[Alpinobombus]]'', 5 species
                     |2=[[Bombus (subgenus)|''Bombus'']], 5 species
                     }}
                  }}
               |2={{clade
                  |1=''[[Alpigenobombus]]'', 7 species
                  |2=''[[Melanobombus]]'', 17 species
                  |3={{clade
                     |1=''[[Sibiricobombus]]'', 7 species
                     |2=''[[Cullumanobombus]]'', 23 species
                     }}
                  }}
              }}
         }}
       }}
   }}
}}
:::<small>Subgenera of the genus ''Bombus''</small>

== Description ==

{{further|Characteristics of common wasps and bees}}

Bumblebees vary in appearance, but are characteristically plump and densely furry. They are larger, broader and stouter-bodied than honeybees, and the tip of the abdomen is more rounded. Many species have broad bands of colour, whose patterns help to distinguish different species. Whereas honeybees have short tongues and therefore mainly pollinate open flowers, some bumblebee species have long tongues and collect nectar from flowers that are closed into a tube.<ref>{{cite web |title=The differences between bumblebees and honeybees |publisher=[[Bumblebee Conservation Trust]] |url=http://bumblebeeconservation.org/about-bees/faqs/honeybees-vs-bumblebees/ |access-date=23 February 2015 |archive-url=https://web.archive.org/web/20150228004017/http://bumblebeeconservation.org/about-bees/faqs/honeybees-vs-bumblebees |archive-date=28 February 2015}}</ref> Bumblebees have fewer stripes (or none), and usually have part of the body covered in black fur, while honeybees have many stripes including several grey stripes on the abdomen.<ref>{{cite web |last=Wild |first=Alex |date=2011-10-11 |title=How to tell the difference between honey bees and bumble bees |work=MYRMECOS |url=http://www.myrmecos.net/2011/10/11/how-to-tell-the-difference-between-honey-bees-and-bumble-bees/ |access-date=23 February 2015 |archive-date=23 February 2015 |archive-url=https://web.archive.org/web/20150223133228/http://www.myrmecos.net/2011/10/11/how-to-tell-the-difference-between-honey-bees-and-bumble-bees/ }}</ref> Sizes are very variable even within species; the largest British species, ''B. terrestris'', has queens up to {{cvt|22|mm|1}} long, males up to {{cvt|16|mm|1}} long, and workers between {{cvt|11|and(-)|17|mm|1}} long.<ref>{{cite web |title=Bumblebee species |publisher=Bumblebee.org |url=http://www.bumblebee.org/key.htm |access-date=23 February 2015}}</ref> The largest bumblebee species in the world is ''[[Bombus dahlbomii|B. dahlbomii]]'' of Chile, up to about {{cvt|40|mm|1}} long, and described as "flying mice" and "a monstrous fluffy ginger beast".<ref>{{cite news |last=Johnston |first=Ian |date=6 July 2014 |title=Bye bye big bee: In South America, the world's largest bumblebee is at risk from imported rivals |newspaper=[[The Independent]] |url=https://www.independent.co.uk/environment/nature/bye-bye-big-bee-in-south-america-the-worlds-largest-bumblebee-is-at-risk-from-imported-rivals-9587240.html}}</ref>

== Distribution and habitat ==

=== Abundance and diversity === 

Bumblebees are most abundant across [[Temperate climate|temperate]] and [[Montane ecosystem|montane ecosystems]] of the Northern Hemisphere, with the greatest species richness found in Eurasia and North America.<ref>{{cite web |title=Map at: Bumblebees of the world |publisher=[[Natural History Museum, London|Natural History Museum]] |url=http://www.nhm.ac.uk/research-curation/projects/bombus/introduction.html |access-date=9 July 2007}}</ref> Bumblebees have a largely [[cosmopolitan distribution]] but are absent from Australia (apart from Tasmania, where they have been introduced<ref name="Larkins-2012">{{cite news |last1=Larkins |first1=Damien |date=18 September 2012 |title=Blight of the bumble bee spreads in Tasmania |url=https://www.abc.net.au/local/stories/2012/09/18/3592865.htm |access-date=20 November 2023 |work=[[ABC Radio Hobart]] |publisher=[[Australian Broadcasting Corporation]]}}</ref>) and occur in Africa only north of the Sahara.<ref name="BugGuide.Net">{{cite web |title=Genus ''Bombus'' – Bumble Bees |url=http://bugguide.net/node/view/3077 |access-date=12 February 2015 |website=BugGuide.Net}}</ref> More than a hundred years ago they were also introduced to New Zealand, where they play an important role as efficient pollinators.<ref>{{cite journal |last1=Gurr |first1=L. |date=1 January 1974 |title=The Role of Bumblebees as Pollinators of Red Clover and Lucerne in New Zealand: A Review and Prospect |url=https://www.nzgajournal.org.nz/index.php/ProNZGA/article/view/1417/1045 |journal=Proceedings of the New Zealand Grassland Association |pages=111–122 |doi=10.33584/jnzg.1974.36.1417}}</ref>

At the northern limits of their range, species such as ''Bombus polaris'', ''B. alpinus'', and the parasitic ''B. hyperboreus'' occupy Arctic tundra ecosystems that extend as far north as [[Greenland]] and Canada's [[Ellesmere Island]]. These populations endure some of the planet's shortest flowering seasons and coldest conditions, marking the northernmost boundary of [[Eusociality|eusocial]] insect life.<ref>{{cite journal |last1=Milliron |first1=H. E. |last2=Oliver |first2=D. R. |year=1966 |title=Bumblebees from northern Ellesmere Island, with observations on usurpation by ''Megabombus hyperboreus'' (Schönh.) |journal=Canadian Entomologist |doi=10.4039/Ent98207-2 |volume=98 |issue=2 |pages=207–213|s2cid=84324577 }}</ref>

=== Physiological adaptations === 
<!--misplaced section?-->
One reason for bumblebee presence in such cold places is that they can regulate their [[Thermoregulation|body temperature]] through several physiological mechanisms. They use [[Sunlight|solar radiation]] to warm themselves, generate heat internally through "shivering" known as [[heterothermy]], and employ [[countercurrent exchange]] to retain heat.<ref>{{Cite journal |last=Heinrich |first=B. |date=1976-06-01 |title=Heat exchange in relation to blood flow between thorax and abdomen in bumblebees |url=https://journals.biologists.com/jeb/article/64/3/561/22298/Heat-exchange-in-relation-to-blood-flow-between |journal=Journal of Experimental Biology |language=en |volume=64 |issue=3 |pages=561–585 |bibcode=1976JExpB..64..561H |doi=10.1242/jeb.64.3.561 |issn=0022-0949 |pmid=945321}}</ref> Although other bees show similar forms of thermoregulation, these mechanisms are especially well developed and extensively studied in bumblebees.<ref name="Heinrich-19812">{{cite book |last=Heinrich |first=B. |title=Insect Thermoregulation |publisher=Krieger Publishing Company |year=1981 |isbn=978-0-471-05144-2}}</ref> They also adapt to high-elevation environments by increasing their wing stroke amplitude to sustain flight in thin air.<ref>{{cite journal |last1=Dillon |first1=Michael E. |last2=Dudley |first2=Robert |date=February 2014 |title=Surpassing Mt. Everest: extreme flight performance of alpine bumble-bees |journal=Biology Letters |volume=10 |issue=2 |doi=10.1098/rsbl.2013.0922 |pmc=3949368 |pmid=24501268 |article-number=20130922}}</ref>

== Biology ==

[[File:Bumblebee heuchera.jpg|thumb|right|upright|A common carder bumblebee ''[[Bombus pascuorum]]'' extending its tongue towards a ''[[Heuchera]]'' [[inflorescence]]]]

=== Feeding ===

[[File:Yellowfaced lBumblebee foraging.webm|thumb|thumbtime=28|A [[Bombus vosnesenskii|yellow-faced bumblebee]] foraging on [[Eschscholzia californica|California poppy]]]]

The bumblebee tongue (the [[proboscis]]) is a long, hairy structure that extends from a sheath-like modified maxilla. The primary action of the tongue is lapping or repeated dipping of the tongue into liquid.<ref>{{cite journal |doi=10.1007/BF00377639 |pmid=28311376 |last=Harder |first=L.D. |year=1986 |title=Effects of nectar concentration and flower depth on flower handling efficiency of bumble bees |journal=Oecologia |volume=69 |issue=2|pages=309–315 |bibcode=1986Oecol..69..309H |s2cid=30088277 }}</ref> 
The tip of the tongue probably acts as a suction cup and during lapping, nectar may be drawn up the proboscis by [[capillary action]]. When at rest or flying, the proboscis is kept folded under the head. The longer the tongue, the deeper the bumblebee can probe into a flower and bees probably learn from experience which flower source is best-suited to their tongue length.<ref>{{cite book |last=Heinrich |first=Bernd |title=Bumblebee Economics |url=https://archive.org/details/bumblebeeeconomi0000hein|url-access=registration |year=2004 |publisher=[[Harvard University Press]] |isbn=978-0-674-01639-2 |page=[https://archive.org/details/bumblebeeeconomi0000hein/page/152 152]}}</ref> Bees with shorter proboscides, like ''[[Bombus bifarius]]'', have a more difficult time foraging nectar relative to other bumblebees with longer proboscides; to overcome this disadvantage, ''B. bifarius'' workers were observed to lick the back of spurs on the nectar duct, which resulted in a small reward.<ref>{{Cite journal |jstor= 3548471 |title=Effects of nectar robbing on nectar dynamics and bumblebee foraging strategies in ''Linaria vulgaris'' (Scrophulariaceae) |last1=Newman |first1=Daniel A. |year=2005 |journal=Okies |doi =10.1111/j.0030-1299.2005.13884.x |last2=Thomson |first2=James D. |last3=Ranta |first3=Esa |volume=10 |issue=2 |pages=309–320 |bibcode=2005Oikos.110..309N}}</ref>

=== Wax production ===

The exoskeleton of the [[abdomen]] is divided into plates called dorsal [[tergum|tergites]] and ventral [[Sternum (arthropod anatomy)|sternites]]. Wax is secreted from [[gland]]s on the abdomen and extruded between the sternites where it resembles flakes of [[dandruff]]. It is secreted by the queen when she starts a nest and by young workers. It is scraped from the abdomen by the legs, moulded until malleable and used in the construction of honeypots, to cover the eggs, to line empty cocoons for use as storage containers and sometimes to cover the exterior of the nest.<ref name="Bumblebee.org">{{cite web |url=http://www.bumblebee.org/body.htm |title=The bumblebee body |publisher=Bumblebee.org |access-date=12 February 2015}}</ref>

=== Coloration ===

[[File:Bombus.barbutellus.-.lindsey.jpg|thumb|upright|Cuckoo bumblebees, like this ''[[Bombus barbutellus]]'', have similar [[aposematic]] (warning) coloration to nest-making bumblebees, and may also [[mimicry|mimic]] their host species.]]

{{further|aposematism|mimicry}}

The black-and-yellow coloration of bumblebees acts as an aposematic (warning) signal to predators, indicating that the insects can inflict a painful sting.<ref>Poulton, E. B. (1890). ''The Colours of Animals: Their Meaning and Use Especially Considered in the Case of Insects''. London: Kegan Paul, Trench, Trübner & Co. pp. 100–104.</ref> This visual warning serves as an anti-predator adaptation that discourages birds and other vertebrates, representing a common example of aposematism among members of the Hymenoptera.<ref>Williams, P. (2007). "The distribution of bumblebee colour patterns worldwide". ''Biological Journal of the Linnean Society''. 92 (1): 97–118. doi:10.1111/j.1095-8312.2007.00878.x.</ref> Depending on the species and [[polymorphism (biology)|morph]], the warning colours range from entirely black, to bright yellow, red, orange, white, and pink.<ref name="Williams-2007">{{cite journal |last=Williams |first=Paul H. |year=2007 |title=The distribution of bumblebee colour patterns world-wide: possible significance for thermoregulation, crypsis, and warning mimicry |journal=Biological Journal of the Linnean Society |volume=92 |issue=1 |pages=97–118 |doi=10.1111/j.1095-8312.2007.00878.x |doi-access=free }}</ref> [[Diptera]]n flies in the families [[Syrphidae]] (hoverflies), [[Asilidae]] (robber flies), [[Horse-fly|Tabanidae]] (horseflies), [[Oestridae]] (bot or warble flies) and [[Bombyliidae]] (bee flies, such as ''[[Bombylius major]]'') all include [[Batesian mimics]] of bumblebees, resembling them closely enough to deceive at least some predators.<ref name="Thorp-1983">{{cite book |last1=Thorp |first1=Robbin W. |url=https://books.google.com/books?id=v1eJ3fWwshIC&pg=PA9 |title=Bumble Bees and Cuckoo Bumble Bees of California (Hymenoptera, Apidae) |last2=Horning |first2=Donald S. |last3=Dunning |first3=Lorry L. |publisher=[[University of California Press]] |year=1983 |isbn=978-0-520-09645-5 |page=9}}</ref>

Many species of ''Bombus'', including the ''Psithyrus'' group of cuckoo bumblebees, have evolved a form of [[Müllerian mimicry|Müllerian]] mimicry. This is a system in which different bumblebee species within the same region share similar warning color patterns, so that a predator only has to learn once to avoid any of them. In California, for example, several largely black species like ''B. californicus'', ''B. caliginosus'', ''B. vandykei'', ''B. vosnesenskii'', ''B. insularis'', and ''B. fernaldae'', form one such mimicry group. Another group in the same region includes species banded in black and yellow. In both cases, the shared coloration gives all members of the group a selective advantage.<ref name="Williams2007">{{cite journal |last=Williams |first=Paul |title=The distribution of bumblebee colour patterns worldwide: possible significance for thermoregulation, crypsis, and warning mimicry |journal=Biological Journal of the Linnean Society |volume=92 |issue=1 |date=2007 |doi=10.1111/j.1095-8312.2007.00878.x |doi-access=free |pages=97–118}}</ref>

Parasitic, or cuckoo, bumblebees also tend to resemble their hosts more closely than would be expected by chance, especially in regions such as Europe where parasite and host species have evolved together. This resemblance is likely another case of Müllerian mimicry, rather than a strategy to deceive the host through [[aggressive mimicry]].<ref>Fisher, R. M. & Sampson, J. (1992). "Mimetic coevolution between cuckoo bumblebees and their hosts". ''Evolution''. 46 (3): 775–783.</ref><!--check source/find newer source: this is odd as the specific resemblance directly implies aggressive mimicry-->

=== Temperature control ===

[[File:Bumblebees in rain.webm|thumb|right|thumbtime=38|Bumblebees can be active in cooler and less favorable weather than most other flying insects. Here it is cool and raining. (with audio)]]

Bumblebees are active under conditions during which honeybees and other smaller bees stay at home, and can readily absorb heat from even weak sunshine.<ref name="Macdonald-2003">{{harvnb|Macdonald|2003|p=6}}</ref> The thick pile created by long [[seta]]e (bristles) acts as insulation to keep bumblebees warm in cold weather; species from cold climates have longer setae (and thus thicker insulation) than those from the tropics.<ref>{{cite journal |last1=Peat |first1=J. |author2=Darvill, B. |author3=Ellis, J. |author4=Goulson, Dave |author4-link=Dave Goulson |title=Effects of climate on intra- and interspecific size variation in bumble-bees |journal=Functional Ecology |year=2005 |volume=19 |issue=1 |pages=145–151 |url=https://www.sussex.ac.uk/webteam/gateway/file.php?name=peat-et-al-funct-ecol-2005.pdf&site=411 |doi=10.1111/j.0269-8463.2005.00946.x|doi-access=free |bibcode=2005FuEco..19..145P }}</ref> The temperature of the flight muscles, which occupy much of the thorax, needs to be at least {{convert|30|°C}} before flight can take place. The muscle temperature can be raised by shivering. It takes about five minutes for the muscles to reach this temperature at an air temperature of {{convert|13|°C}}.<ref>{{cite web |url=http://www.bumblebee.org/bodyWing.htm |title=Bumblebee wings |publisher=Bumblebee.org |access-date=14 February 2015}}</ref>

==== Chill-coma temperature ====

The chill-coma temperature in relation to flying insects is the temperature at which flight muscles cannot be activated. Compared to honey bees and carpenter bees, bumblebees have the lowest chill-coma temperature. Of the bumblebees ''[[Two-spotted bumble bee|Bombus bimaculatus]]'' has the lowest at {{convert|7|°C}}. However, bumblebees have been seen to fly in colder ambient temperatures. This discrepancy is likely because the chill-coma temperature was determined by tests done in a laboratory setting. However, bumblebees live in insulated shelters and can shiver to warm up before venturing into the cold.<ref>{{cite journal |title=Comparative Study of Chill-Coma Temperatures and Muscle Potentials in Insect Flight Muscles |url=http://jeb.biologists.org/content/150/1/221 |journal=[[Journal of Experimental Biology]] |date=May 1990 |pages=221–231 |volume=150 |issue=1 |first1=Franz |last1=Goller |first2=Harald |last2=Esch |doi=10.1242/jeb.150.1.221 |doi-access=free |bibcode=1990JExpB.150..221G }}</ref>

=== Communication and social learning ===

Bumblebees do not have ears, and it is not known whether or how well they can hear. However, they are sensitive to vibrations transmitted through substrates such as wood or other materials.<ref name="BeeCulture2016">{{cite web |last=Collison |first=Clarence |title=A closer look: sound generation and hearing |website=Bee Culture |date=22 February 2016 |url=https://beeculture.com/a-closer-look-sound-generation-and-hearing/ |access-date=20 October 2025}}</ref>

Unlike the well-known "dance" communication of honeybees, bumblebees do not perform a spatial waggle or round dance to indicate the location of food sources. Instead, when a forager returns from a successful trip to the nest, it often moves rapidly and excitedly around the nest for several minutes before departing again to forage.<ref name="XercesBumbleBees">{{cite web |title=About Bumble Bees |publisher=[[Xerces Society]] |url=https://xerces.org/bumble-bees/about |access-date=20 October 2025}}</ref>

Bumblebees have also been observed to engage in social learning. In experiments with Bombus terrestris, workers were trained to solve a novel task (string-pulling) to obtain a reward, and naïve individuals that observed trained demonstrators were significantly more successful than those that did not.<ref name="Alem 2016">{{cite journal |last1=Alem |first1=Sylvain |last2=Perry |first2=Clint J. |last3=Zhu |first3=Xingfu |last4=Loukola |first4=Olli J. |last5=Ingraham |first5=Thomas |last6=Søvik |first6=Eirik |last7=Chittka |first7=Lars |title=Associative Mechanisms Allow for Social Learning and Cultural Transmission of String Pulling in an Insect |journal=[[PLOS Biology]] |volume=14 |issue=10 |date=4 October 2016 |pmid=27701411 |pmc=5049772 |doi=10.1371/journal.pbio.1002564 |doi-access=free |article-number=e1002564}}</ref> Furthermore, subsequent work showed that novel problem-solving behaviours can spread through bumblebee colonies via social learning under open-diffusion conditions.<ref name="Bridges2023">{{cite journal |last1=Bridges |first1=Alice D. |last2=MaBouDi |first2=HaDi |last3=Procenko |first3=Olga |last4=Lockwood |first4=Charlotte |last5=Mohammed |first5=Yaseen |last6=Kowalewska |first6=Amelia |last7=Romero González |first7=José Eric |last8=Woodgate |first8=Joseph L. |last9=Chittka |first9=Lars |title=Bumblebees acquire alternative puzzle-box solutions via social learning |journal=[[PLOS Biology]] |volume=21 |issue=3 |date=2023 |pmid=36881588 |pmc=9990933 |doi=10.1371/journal.pbio.3002019 |doi-access=free |article-number=e3002019}}</ref>

=== Reproduction and nesting ===

[[File:Bumblebee nest.jpg|thumb|Nest of red-tailed bumblebee. ''[[Bombus lapidarius]]'', showing [[wax]] pots full of honey]]

{{further|haplodiploidy|worker policing}}

Nest size depends on species of bumblebee. Most form [[colony (biology)|colonies]] of between 50 and 400 individuals,<ref name="Bumblebee Conservation Trust-2"/> but colonies have been documented as small as ~20 individuals and as large as 1700.<ref>{{cite journal |last1=Cueva del Castillo |first1=R. |last2=Sanabria-Urbán |first2=S. |last3=Serrano-Meneses |first3=M. A. |year=2015|title=Trade-offs in the evolution of bumblebee colony and body size: a comparative analysis |journal=Ecology and Evolution |volume=5 |issue=18 |pages=3914–3926 |pmid=26445652 |pmc=4588658 |doi=10.1002/ece3.1659 |bibcode=2015EcoEv...5.3914C}}</ref> These nests are small compared to honeybee hives, which hold about 50,000 bees. Many species nest underground, choosing old [[rodent]] burrows or sheltered places, and avoiding places that receive direct sunlight that could result in overheating. Other species make nests above ground, whether in thick grass or in holes in trees. A bumblebee nest is not organised into hexagonal combs like that of a honeybee; the cells are instead clustered together untidily. The workers remove dead bees or larvae from the nest and deposit them outside the nest entrance, helping to prevent disease. Nests in temperate regions last only for a single season and do not survive the winter.<ref name="Bumblebee Conservation Trust-2">{{cite web |title=Bumblebee nests |url=http://bumblebeeconservation.org/about-bees/habitats/bumblebee-nests/ |publisher=[[Bumblebee Conservation Trust]] |access-date=13 February 2015 |archive-url=https://web.archive.org/web/20170922230805/https://bumblebeeconservation.org/about-bees/habitats/bumblebee-nests/ |archive-date=22 September 2017}}</ref>

In the early spring, the queen comes out of [[diapause]] and finds a suitable place to create her colony. Then she builds wax cells in which to lay her eggs which were fertilised the previous year. The eggs that hatch develop into female workers, and in time, the queen populates the colony, with workers feeding the young and performing other duties similar to honeybee workers. In [[Temperate climate|temperate zone]]s, young queens ([[gyne]]s) leave the nest in the autumn and [[mating|mate]], often more than once, with males ([[drone (bee)|drone]]s) that are forcibly driven out of the colony.<ref name="Goulson-2013a"/> The drones and workers die as the weather turns colder; the young queens feed intensively to build up stores of fat for the winter. They survive in a resting state (diapause), generally below ground, until the weather warms up in the spring with the [[early bumblebee]] being the species that is among the first to emerge.<ref name="Goulson-2013a"/><ref>{{Cite journal |last1=Lye |first1=Gillian C. |last2=Osborne |first2=Juliet L. |last3=Park |first3=Kirsty J. |last4=Goulson |first4=Dave |author4-link=Dave Goulson |title=Using citizen science to monitor ''Bombus'' populations in the UK: nesting ecology and relative abundance in the urban environment |journal=Journal of Insect Conservation |date=November 2011 |pages=697–707 |volume=16 |issue=5 |doi=10.1007/s10841-011-9450-3 |s2cid=3956485}}</ref><ref name="Bumblebee Conservation Trust">{{cite web |title=The Bumblebee Lifecycle |url=http://bumblebeeconservation.org/about-bees/lifecycle/ |publisher=Bumblebee Conservation Trust |access-date=11 February 2015}}</ref> Many species of bumblebee follow this general trend within the year. ''[[Bombus pensylvanicus]]'' is a species that follows this type of colony cycle.<ref name="University of Wisconsin La Crosse-2013">{{cite web |title=Bombus pensylvanicus |url=http://bioweb.uwlax.edu/bio210/s2013/netwal_meli/reproduction.htm |publisher=University of Wisconsin La Crosse |year=2013}}</ref> For this species the cycle begins in February, reproduction starts in July or August, and ends in the winter months. The queen remains in hibernation until spring of the following year in order to optimize conditions to search for a nest.<ref name="Di Trani de la Hoz-2006">{{cite journal |first=Juan |last=Di Trani de la Hoz |title= Phenology of ''Bombus pennsylvanicus sonorus'' Say (Hymenoptera: Apidae) in Central Mexico |journal= Neotropical Entomology |volume=35 |issue=5 |pages= 588–95 |year=2006 |doi=10.1590/S1519-566X2006000500004 |doi-broken-date=11 July 2025 |pmid=17144129 |url=http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1519-566X2006000500004 }}</ref>

<!--[[File:Bumble bee nest hole.JPG|thumb|left|upright|A queen buff-tailed bumblebee, ''[[Bombus terrestris]]'', digging a nest hole]]-->
[[File:Nest of the Common Humble-Bee Plate 15 Jardine.jpg|thumb|left|upright=1.2|Bumblebee life-cycle showing adults and [[larvae]] in nest of ''B. terrestris''. Engraved in 1840 by [[William Home Lizars]] after drawing probably by [[James Hope Stewart]].<ref>'Nest of the Common Humble-Bee (''B. terrestris'')', Plate 15 from ''[[Sir William Jardine, 7th Baronet#The Naturalist's Library|The Naturalist's Library]]'', Vol. VI. ''Entomology'', by [[Sir William Jardine, 7th Baronet|Sir William Jardine]]. Edinburgh: W. H. Lizars, 1840</ref>]]

In fertilised queens, the ovaries only become active when the queen starts to lay. An egg passes along the [[oviduct]] to the vagina where there is a chamber called the [[spermatheca]], in which the sperm from the mating is stored. Depending on need, she may allow her egg to be fertilised. Unfertilised eggs become [[haploid]] males; fertilised eggs grow into [[diploid]] females and queens.<ref name="Biobees Bumblebee Pollination">{{cite web |title=Biology |url=http://www.biobees.co.nz/biology.html |publisher=Biobees Bumblebee Pollination |access-date=13 February 2015 |archive-date=13 February 2015 |archive-url=https://web.archive.org/web/20150213181511/http://www.biobees.co.nz/biology.html }}</ref> The [[hormone]]s that stimulate the development of the ovaries are suppressed in female worker bees, while the queen remains dominant.<ref name="Goulson-2013a"/>

To develop, the [[larva]]e must be fed both nectar for [[carbohydrate]]s and pollen for [[protein]]. Bumblebees feed nectar to the larvae by chewing a small hole in the brood cell into which they regurgitate nectar. Larvae are fed pollen in one of two ways, depending on the bumblebee species. Pocket-making bumblebees create pockets of pollen at the base of the brood-cell clump from which the larvae feed themselves. Pollen-storing bumblebees keep pollen in separate wax pots and feed it to the larvae.<ref name="Evans-2007">{{cite book |title=Befriending Bumble Bees |last1=Evans |first1=Elaine |last2=Burns |first2=Ian |last3=Spivak |first3=Marla |year=2007 |publisher=[[University of Minnesota Press]] |location=St. Paul}}</ref>

[[File:Apoidea.jpg|thumb|An above-ground nest, hidden in grass and moss, of the common carder bee, ''[[Bombus pascuorum]]''. The wax canopy or involucrum has been removed to show winged [[worker (bee)|workers]] and [[pupae]] in irregularly placed wax cells.]]

After the emergence of the first or second group of offspring, workers take over the task of foraging and the queen spends most of her time laying eggs and caring for larvae. The colony grows progressively larger and eventually begins to produce males and new queens.<ref name="Goulson-2013a">{{harvnb|Goulson|2013|pages=16–24}}</ref>
Bumblebee workers can lay unfertilised haploid eggs (with only a single set of [[chromosome]]s) that develop into viable male bumblebees. Only fertilised queens can lay diploid eggs (one set of chromosomes from a drone, one from the queen) that mature into workers and new queens.<ref>{{harvnb|Goulson|2013|pages=108–114}}</ref>

In a young colony, the queen minimises reproductive competition from workers by suppressing their egg-laying through physical aggression and [[pheromone]]s.<ref name="Van Honk-1980">{{cite journal |last1=Van Honk |first1=C. G. J. |last2=Velthuis |first2=H. H. W. |last3=Röseler |first3=P.-F. |last4=Malotaux |first4=M. E. |year=1980 |title=The mandibular glands of ''Bombus terrestris'' queens as a source of queen pheromones |journal=Entomologia Experimentalis et Applicata |volume=28 |issue=2 |pages=191–198 |doi=10.1111/j.1570-7458.1980.tb03004.x|bibcode=1980EEApp..28..191H |s2cid=84780948 }}</ref> [[Worker policing]] leads to nearly all eggs laid by workers being eaten.<ref name="Zanette-2012"/> Thus, the queen is usually the mother of all of the first males laid. Workers eventually begin to lay male eggs later in the season when the queen's ability to suppress their reproduction diminishes.<ref name="Fletcher-1985">{{cite journal |author1=Fletcher, D. J. C. |author2=Fletcher, Ross K. |year=1985 |title=Regulation of reproduction in eusocial Hymenoptera |journal=Annual Review of Entomology |volume=30 |pages=319–343 |doi=10.1146/annurev.en.30.010185.001535}}</ref> Because of the reproductive [[competition (biology)|competition]] between workers and the queen, bumblebees are considered "primitively eusocial".<ref name="Cardinal-2011"/><ref name="Zanette-2012">{{cite journal |last1=Zanette |first1=L. R. |last2=Miller |first2=S. D. |last3=Faria |first3=C. M.|last4=Almond |first4=E. J. |last5=Huggins |first5=T. J.|last6=Jordan |first6=W. C. |last7=Bourke |first7=A. F. |title=Reproductive conflict in bumblebees and the evolution of worker policing |journal=Evolution |date=December 2012 |volume=66 |issue=12 |pages=3765–3777 |doi=10.1111/j.1558-5646.2012.01709.x |pmid=23206135 |bibcode=2012Evolu..66.3765Z |s2cid=36787898 |url=http://www.repositorio.ufc.br/handle/riufc/64010 }}</ref>

Although a large majority of bumblebees follow such monogynous colony cycles that only involve one queen, some select ''Bombus'' species (such as ''[[Bombus pauloensis]]'') will spend part of their life cycle in a polygynous phase (have multiple queens in one nest during these periods of polygyny).<ref name="Cameron-1998">{{cite journal |last1=Cameron |first1=S .D. |title=Mediators of dominance and reproductive success among queens in the cyclically polygynous neotropical bumble bee ''Bombus atratus'' Franklin |journal=[[Insectes Sociaux]] |year=1998 |volume=45|issue=2 |pages=135–149 |url=http://www.life.illinois.edu/scameron/pdfs/Mediators%20of%20dominance%20and%20reproductive%20success.pdf |doi=10.1007/s000400050075 |s2cid=11849676}}</ref>

===Foraging behaviour===

{{further|Bumblebee communication|nectar robbing}}

[[File:Bombus soroeensis - Jasione montana - Tallinn.jpg|thumb|left|A bumblebee loaded with [[pollen]] in its [[pollen basket]]s]]

[[File:061 Wild Bumblebee in flight pollinating with Crocus Parc naturel régional Jura vaudois Photo by Giles Laurent.jpg|alt=A bumblebee loaded with pollen flying to a flower|thumb|A bumblebee loaded with [[pollen]] flying to a [[Crocus]] ]]

[[File:BumblebeeBlossus 63.webm|thumb|[[Bombus vosnesenskii|Yellow-faced bumblebee]] [[foraging]] [[Ceanothus|California lilac]]. Repeated a second time at one-fourth speed.]]

Bumblebees generally visit flowers that exhibit the bee [[pollination syndrome]] and these patches of flowers may be up to 1–2&nbsp;km from their colony.<ref name="Walther-Hellwig-2000">{{cite journal |author1=Walther-Hellwig, K. |author2=Frankl, R. |year=2000 |title=Foraging distances of ''Bombus muscorum'', ''Bombus lapidarius'', and ''Bombus terrestris'' (Hymenoptera, Apidae) |journal=Journal of Insect Behavior |volume=13 |issue=2 |pages=239–246 |doi=10.1023/A:1007740315207|bibcode=2000JIBeh..13..239W |s2cid=29303814 }}</ref> They tend to visit the same patches of flowers every day, as long as they continue to find nectar and pollen there,<ref name="Dramstad-2003">{{cite journal |author1=Dramstad, W. E. |author2=Fry, G. L. A. |author3=Schaffer, M. J. |year=2003 |title=Bumblebee foraging—is closer really better? |journal=Agriculture, Ecosystems and Environment |volume=95 |issue=1 |pages=349–357 |doi=10.1016/S0167-8809(02)00043-9|bibcode=2003AgEE...95..349D }}</ref> a habit known as pollinator or [[flower constancy]]. While foraging, bumblebees can reach ground speeds of up to {{convert|15|m/s|km/h|abbr=on}}.<ref>{{cite journal |author1=Osborne, J. L. |author2=Clark, S. J. |author3=Morris, R. J. |author4=Williams, I. H. |author5=Riley, J. R. |author6=Smith, A. D. |author7=Reynolds, D. R. |author8=Edwards, A. S. |year=1999 |title=A landscape-scale study of bumble bee foraging range and constancy, using harmonic radar |journal=Journal of Applied Ecology |volume=36 |issue=4 |pages=519–533 |doi=10.1046/j.1365-2664.1999.00428.x|doi-access=free |bibcode=1999JApEc..36..519O }}</ref>

Bumblebees use a combination of colour and spatial relationships to learn which flowers to forage from.<ref>{{cite journal |author1=Blackawton, P. S. |author2= Airzee, S. |author3= Allen, A. |author4=Baker, S. |author5= Berrow, A. |author6= Blair, C. |author7= Churchill, M. |author8= Coles R. F.-J. |author9=Cumming, L. |others=Fraquelli, C. Hackford, A. Hinton Mellor, M. Hutchcroft, B. Ireland, J.; Jewsbury, D.; Littlejohns, A.; Littlejohns, G. M.; Lotto, M.; McKeown, J.; O'Toole, A.; Richards, H.; Robbins-Davey, L.; Roblyn, S.; Rodwell-Lynn, H.; Schenck, D.; Springer, J.; Wishy, A.; Rodwell-Lynn, T.; Strudwick, D.; Lotto, R. B. |display-authors=6 |year=2010 |title=Blackawton bees |journal=Biology Letters |volume=7 |issue=2 |pages=168–72 |pmid=21177694 |pmc=3061190 |doi=10.1098/rsbl.2010.1056 |last10=Fraquelli |first10=L. |last11=Hackford |first11=C. |last12=Hinton Mellor |first12=A. |last13=Hutchcroft |first13=M. |last14=Ireland |first14=B. |last15=Jewsbury |first15=D. |last16=Littlejohns |first16=A. |last17=Littlejohns |first17=G. M. |last18=Lotto |first18=M. |last19=McKeown |first19=J. |last20=O'Toole |first20=A. |last21=Richards |first21=H. |last22=Robbins-Davey |first22=L. |last23=Roblyn |first23=S. |last24=Rodwell-Lynn |first24=H. |last25=Schenck |first25=D. |last26=Springer |first26=J. |last27=Wishy |first27=A. |last28=Rodwell-Lynn |first28=T. |last29=Strudwick |first29=D. |last30=Lotto |first30=R. B.}}</ref> They can also [[electroreception|detect]] both the presence and the pattern of electric fields on flowers, which occur due to [[atmospheric electricity]], and take a while to leak away into the ground. They use this information to find out if a flower has been recently visited by another bee.<ref>{{cite journal |title=Detection and Learning of Floral Electric Fields by Bumblebees |year=2013 |last1=Clarke |first1=D. |last2=Whitney |first2=H.|last3=Sutton |first3=G. |last4=Robert |first4=D. |journal=Science |doi=10.1126/science.1230883 |volume=340 |issue=6128 |pages=66–9 |pmid=23429701|bibcode=2013Sci...340...66C |s2cid=23742599|doi-access=free }}
* {{cite journal |author=Matt Kaplan |date=21 February 2013 |title=Bumblebees sense electric fields in flowers |journal=Nature |doi=10.1038/nature.2013.12480 |doi-access=free}}</ref> Bumblebees can detect the temperature of flowers,<ref>{{cite journal |title=The interaction of temperature and sucrose concentration on foraging preferences in bumblebees |year=2008 |last1=Whitney |first1=H. |last2=Dyer |first2=A.|last3=Rands |first3=S.A. |last4=Glover |first4=B.J. |journal=Naturwissenschaften |doi=10.1007/s00114-008-0393-9 |pmid=18523748 |volume=95 |issue=9 |pages=845–850 |bibcode=2008NW.....95..845W |s2cid=939116 }}</ref> as well as which parts of the flower are hotter or cooler<ref>{{cite journal |title=The diversity of floral temperature patterns, and their use by pollinators|year=2017 |last1=Harrap |first1=M.J.M. |last2=Rands |first2=S.A. |last3=Hempel de Ibarra |first3=N. |last4=Whitney |first4=H.M. |journal=[[eLife]] |doi=10.7554/eLife.31262 |pmid=29254518 |pmc=5736352 |volume=6 |article-number=e31262 |doi-access=free }}</ref> and use this information to recognise flowers. After arriving at a flower, they extract nectar using their long tongues ("[[Tongue|glossa]]e") and store it in their [[crop (anatomy)|crop]]s. Many species of bumblebees also exhibit "nectar robbing": instead of inserting the mouthparts into the flower in the normal way, these bees bite directly through the base of the [[Petal#Corolla|corolla]] to extract nectar, avoiding pollen transfer.<ref name="Maloof-2001">{{cite journal |last=Maloof |first=J. E. |s2cid=33897983 |year=2001 |title=The effects of a bumble bee nectar robber on plant reproductive success and pollinator behavior |journal=[[American Journal of Botany]] |volume=88 |issue=11 |pages=1960–1965 |doi= 10.2307/3558423 |jstor=3558423 |pmid=21669629 }}</ref>

{{multiple image
 |direction=vertical
 |width=220
 |footer=A bumblebee "[[nectar robbing]]" a flower
 |image1=Bumble bee biting.JPG
 |alt1=
 |caption1=Biting open the stem of a flower...
 |image2=Bumble bee feeding.JPG
 |alt2=
 |caption2=...and using its tongue to drink the nectar.
 }}

Pollen is removed from flowers deliberately or incidentally by bumblebees. Incidental removal occurs when bumblebees come in contact with the [[stamen|anthers]] of a flower while collecting nectar. When it enters a flower, the bumblebee's body hairs receive a dusting of pollen from the anthers. In queens and workers this is then groomed into the [[Pollen basket|corbiculae]] (pollen baskets) on the hind legs where it can be seen as bulging masses that may contain as many as a million pollen grains. Male bumblebees do not have corbiculae and do not purposively collect pollen.<ref>{{cite web |url=http://www.bumblebee.org/bodyLegs.htm |title=Bumblebee legs |publisher=Bumblebee.org |access-date=18 February 2015}}</ref> Bumblebees are also capable of [[buzz pollination]], in which they dislodge pollen from the anthers by creating a [[resonance|resonant vibration]] with their flight muscles.<ref>{{cite web |title=Buzz Pollination |last=Leonard |first=Anne |url=http://www.anneleonard.com/buzz-pollination |access-date=11 February 2015}}</ref>

In at least some species, once a bumblebee has visited a flower, it leaves a scent mark on it. This scent mark deters bumblebees from visiting that flower until the scent degrades.<ref name="Goulson-1998">{{cite journal |last1=Goulson |first1=Dave |author1-link=Dave Goulson |author2=Hawson, Sadie A. |author3=Stout, Jane C. |s2cid=2969977 |year=1998 |title=Foraging bumblebees avoid flowers already visited by conspecifics or by other bumblebee species |journal=Animal Behaviour |volume=55 |issue=1 |pages=199–206 |doi=10.1006/anbe.1997.0570 |pmid=9480686 |bibcode=1998AnBeh..55..199G }}</ref> This scent mark is a general chemical bouquet that bumblebees leave behind in different locations (e.g. nest, neutral, and food sites),<ref name="Saleh-2007">{{cite journal |last1=Saleh |first1=Nehal |first2=Alan G. |last2=Scott |first3=Gareth P. |last3=Bryning |first4=Lars |last4=Chittka |name-list-style=amp|year=2007 |title=Bumblebees use incidental footprints to generate adaptive behaviour at flowers and nest |journal=Arthropod-Plant Interactions |volume=1 |issue=2 |pages=119–127 |doi=10.1007/s11829-007-9011-6|s2cid=40995470 }}</ref> and they learn to use this bouquet to identify both rewarding and unrewarding flowers,<ref>{{cite journal |author1=Saleh, Nehal |author2=Chittka, Lars |year=2006 |title=The importance of experience in the interpretation of conspecific chemical signals |journal=[[Behavioral Ecology and Sociobiology]] |volume=61 |issue=2 |pages=215–220 |doi=10.1007/s00265-006-0252-7|bibcode=2006BEcoS..61..215S |s2cid=2052108 }}</ref> and may be able to identify who else has visited a flower.<ref name="Pearce-2017">{{cite journal |author1=Pearce, Richard F. |author2=Giuggioli, Luca |author3=Rands, Sean A. |year=2017 |title=Bumblebees can discriminate between scent-marks deposited by conspecifics |journal=Scientific Reports |volume=7 |article-number=43872 |doi=10.1038/srep43872 |pmid=28266572 |pmc=5339730|bibcode=2017NatSR...743872P }}</ref> Bumblebees rely on this chemical bouquet more when the flower has a high handling time, that is, where it takes a longer time for the bee to find the nectar once inside the flower.<ref>{{cite journal |last1=Saleh |first1=Nehal |first2=Kazuharu |last2=Ohashi |first3=James D. |last3=Thomson |first4=Lars |last4=Chittka  |name-list-style=amp|year=2006 |title=Facultative use of repellent scent mark in foraging bumblebees: complex versus simple flowers |journal=[[Animal Behaviour (journal)|Animal Behaviour]] |volume=71 |issue=4 |pages=847–854 |doi=10.1016/j.anbehav.2005.06.014|bibcode=2006AnBeh..71..847S |s2cid=53167932 }}</ref>

Once they have collected nectar and pollen, female workers return to the nest and deposit the harvest into brood cells, or into [[wax]] cells for storage. Unlike honeybees, bumblebees only store a few days' worth of food, so are much more vulnerable to food shortages.<ref>{{cite web |url=http://www.nhm.ac.uk/nature-online/life/plants-fungi/postcode-plants/article.html |title=Living larders for bumblebees |publisher=Natural History Museum |access-date=20 June 2010 |last1=Comba |first1=Livio |author2=Sarah Corbet }}</ref> Male bumblebees collect only nectar and do so to feed themselves. They may visit quite different flowers from the workers because of their different nutritional needs.<ref>{{harvnb|Macdonald|2003|p=7}}</ref>

===Asynchronous flight muscles===

Bees beat their wings about 200 times a second. Their thorax muscles do not contract on each nerve firing, but rather vibrate like a plucked rubber band. This is efficient, since it lets the system consisting of muscle and wing operate at its resonant frequency, leading to low energy consumption. Further, it is necessary, since insect motor nerves generally cannot fire 200 times per second.<ref name="Scherer">{{cite web |last1=Scherer |first1=C.W. |title=Fastest Wing Beat |url=http://entnemdept.ifas.ufl.edu/walker/ufbir/chapters/chapter_09.shtml |website=Book of Insect Records |publisher=[[University of Florida]] |access-date=29 October 2015}}</ref> These types of muscles are called [[asynchronous muscles]]<ref>{{cite web |url=http://www.amentsoc.org/insects/glossary/terms/asynchronous-muscle |title=Definition of Asynchronous muscle in the Entomologists' glossary |access-date=19 April 2013 |publisher=Department of Entomology, [[North Carolina State University]]}}</ref> and are found in the [[insect wing]] systems in families such as Hymenoptera, Diptera, [[Coleoptera]], and [[Hemiptera]].<ref name="Scherer"/> Bumblebees must warm up their bodies considerably to get airborne at low ambient temperatures. Bumblebees can reach an internal thoracic temperature of 30&nbsp;°C (86&nbsp;°F) using this method.<ref name="Heinrich-1981">{{cite book |last=Heinrich |first=B. |title=Insect Thermoregulation |publisher=Krieger Publishing Company |year=1981 |isbn=978-0-471-05144-2}}</ref><ref name="Schmidt-Nielsen-1997">{{cite book |last=Schmidt-Nielsen |first=Knut |author-link=Knut Schmidt-Nielsen |title=Animal Physiology: Adaptation and Environment |url=https://books.google.com/books?id=Af7IwQWJoCMC&pg=PA290 |date=10 April 1997 |publisher=[[Cambridge University Press]] |isbn=978-0-521-57098-5 |pages=290–291}}</ref>

===Cuckoo bumblebees===

{{main|Psithyrus}}

[[File:Bumblebee January 2008-4.jpg|thumb|upright=0.9|The cuckoo bumblebee ''B. vestalis'', a parasite of ''B. terrestris'']]

Bumblebees of the subgenus ''[[Psithyrus]]'' (known as 'cuckoo bumblebees', and formerly considered a separate genus) are [[brood parasite]]s,<ref name="Erler-2010">{{cite journal |last1=Erler |first1=S. |last2=Lattorff |first2=H. M. G.|title=The degree of parasitism of the bumblebee (''Bombus terrestris'') by cuckoo bumblebees (''Bombus (Psithyrus) vestalis'') |journal=Insectes Sociaux |year=2010 |volume=57 |issue=4 |pages=371–377 |doi=10.1007/s00040-010-0093-2 |s2cid=853556 |url=<!--https://www.researchgate.net/profile/H_Michael_Lattorff/publication/225032044_The_degree_of_parasitism_of_the_bumblebee_(Bombus_terrestris)_by_cuckoo_bumblebees_(Bombus_(Psithyrus)_vestalis)/links/0fcfd4fbcbfcb5aed6000000.pdf-->}}</ref> sometimes called [[kleptoparasitism|kleptoparasites]],<ref name="Slater-2005">{{cite book |author1=Peter J.B. Slater |author2=Jay S. Rosenblatt |author3=Charles T. Snowdon |author4=Timothy J. Roper |author5=H. Jane Brockmann |author-link5=H. Jane Brockmann |author6=Marc Naguib |title=Advances in the Study of Behavior |url=https://books.google.com/books?id=WQl2s_xwfagC&pg=PA365 |date=30 January 2005 |publisher=[[Academic Press]] |isbn=978-0-08-049015-1 |page=365}}</ref> in the colonies of other bumblebees, and have lost the ability to collect pollen. Before finding and invading a host colony, a ''Psithyrus'' female, such as that of the ''Psithyrus'' species of ''[[Bombus sylvestris|B. sylvestris]]'',<ref>Pierre Rasmont. "''Bombus (Psithyrus) sylvestris'' (Lepeletier, 1832)". Université de Mons. Retrieved 6 January 2013.</ref> feeds directly from flowers. Once she has infiltrated a host colony, the ''Psithyrus'' female kills or subdues the queen of that colony, and uses pheromones and physical attacks to force the workers of that colony to feed her and her young.<ref name="Zimma-2003">{{cite journal |last1=Zimma |first1=B. O. |first2=M. |last2=Ayasse |first3=J. |last3=Tengo |first4=F. |last4=Ibarra |first5=C. |last5=Schulz |first6=W. |last6=Francke  |name-list-style=amp |year=2003 |title=Do social parasitic bumblebees use chemical weapons? (Hymenoptera, Apidae) |journal=[[Journal of Comparative Physiology A]] |volume=189 |issue=10 |pages=769–775 |doi=10.1007/s00359-003-0451-x |pmid=12955437|s2cid=24441556 }}</ref> Usually, cuckoo bumblebees can be described as queen-intolerant [[inquiline]]s, since the host queen is often killed to enable the parasite to produce more offspring,<ref name="Erler-2010"/> though some species, such as ''[[Bombus bohemicus|B. bohemicus]]'', actually enjoy increased success when they leave the host queen alive.<ref name="Fisher-1988">{{cite journal|last=Fisher|first=R.M.|title=Observations on the Behaviors of Three European Cuckoo Bumble Bee Species (Psithyrus)|journal=Insectes Sociaux|date=December 1988|volume=35|issue=4|pages=341–354|doi=10.1007/BF02225810|s2cid=24071728}}</ref>

The female ''Psithyrus'' has a number of morphological adaptations for combat, such as larger mandibles, a tough cuticle and a larger venom sac that increase her chances of taking over a nest.<ref name="Fisher-1992">{{cite journal |author1=Fisher, R. M. |author2=Sampson, B. J. |year=1992 |title=Morphological specializations of the bumble bee social parasite ''Psithyrus ashtoni'' (Cresson) (Hymenoptera, Apidae) |journal=Canadian Entomologist |volume=124 |issue=1 |pages=69–77 |doi=10.4039/Ent12469-1|s2cid=83598728 }}</ref> Upon emerging from their cocoons, the ''Psithyrus'' males and females disperse and mate. The males do not survive the winter but, like nonparasitic bumblebee queens, ''Psithyrus'' females find suitable locations to spend the winter and enter diapause after mating. They usually emerge from [[hibernation]] later than their host species. Each species of cuckoo bumblebee has a specific host species, which it may physically resemble.<ref>{{harvnb|Macdonald|2003|p=12}}</ref> In the case of the parasitism of ''B. terrestris'' by ''[[Vestal cuckoo bumblebee|B. (Psithyrus) vestalis]]'', genetic analysis of individuals captured in the wild showed that about 42% of the host species' nests at a single location{{efn|The study location was the Botanical Garden Halle (Saale) in Germany, described as a flower-rich region with high and stable abundance of both host and cuckoo species. 24 ''B. terrestris'' workers and 24 drones were captured on foraging flights. 24 male ''B. vestalis'' were similarly captured. DNA analysis was used to estimate how many colonies these individuals came from.<ref name="Erler-2010"/>}} had "[lost] their fight against their parasite".<ref name="Erler-2010"/>

===Sting===

Queen and worker bumblebees can [[bee sting|sting]]. Unlike in honeybees, a bumblebee's [[stinger]] lacks barbs, so the bee can sting repeatedly without leaving the stinger in the wound and thereby injuring itself.<ref>{{cite web |url=http://www.straightdope.com/mailbag/mbeesting.htm |title=Do bumblebees sting? Once or many times? |access-date=9 July 2007 |website=Straight Dope |archive-url=https://web.archive.org/web/20071230082748/http://www.straightdope.com/mailbag/mbeesting.htm |archive-date=30 December 2007}}</ref><ref>{{cite web |url=http://beespotter.mste.illinois.edu/topics/stings/ |title=Bee Stings, BeeSpotter, University of Illinois |publisher=Beespotter.mste.illinois.edu |access-date=25 May 2012}}</ref> Bumblebee species are not normally aggressive, but may sting in defence of their nest, or if harmed. Female cuckoo bumblebees aggressively attack host colony members, and sting the host queen, but ignore other animals unless disturbed.<ref>{{harvnb|Goulson|2013|pages=118–121}}</ref>

==Predators, parasites, and pathogens==

[[File:Catastrophe for the bumblebees - geograph.org.uk - 899562.jpg|thumb|left|Bumblebee nest dug up and destroyed by a predator, probably a [[badger]] ]]

Bumblebees, despite their ability to sting, are eaten by certain predators. Nests may be dug up by [[badger]]s and eaten whole, including any adults present.<ref>{{harvnb|Goulson|2013|page=132}}</ref> Adults are preyed upon by robber flies and [[Beewolf|beewolves]] in North America.<ref>{{harvnb|Goulson|2013|page=126}}</ref> In Europe, birds including [[bee-eater]]s and [[shrike]]s capture adult bumblebees on the wing; smaller birds such as [[great tit]]s also occasionally learn to take bumblebees, while [[camouflage]]d [[crab spider]]s catch them as they visit flowers.<ref>{{harvnb|Goulson|2013|pages=126–129}}</ref>

[[File:Lanius.excubitor5.-.lindsey.jpg|thumb|upright=0.6|Bumblebee stored as food by a [[great grey shrike]] ]]

The [[great grey shrike]] is able to detect flying bumblebees up to {{cvt|100|m}} away; once captured, the sting is removed by repeatedly squeezing the insect with the mandibles and wiping the abdomen on a branch.<ref>{{cite book |last1=Cramp |first1=Stanley |title=Handbook of the Birds of Europe, the Middle East and North Africa. Volume VII: Flycatchers to Shrikes |date=1993 |publisher=RSPB / Oxford University Press |location=Oxford |isbn=978-0-198-57510-8 |page=505|display-authors=etal}}</ref> The [[European honey buzzard]] follows flying bees back to their nest, digs out the nest with its feet, and eats larvae, pupae and adults as it finds them.<ref>{{cite web|title=Honey Buzzard: Feeding|url=http://www.rspb.org.uk/discoverandenjoynature/discoverandlearn/birdguide/name/h/honeybuzzard/feeding.aspx|publisher=Royal Society for the Protection of Birds|access-date=19 February 2015}}</ref>

Bumblebees are parasitised by tracheal mites, ''[[Locustacarus buchneri]]''; [[protozoa]]ns including ''[[Crithidia]] bombi'' and ''[[Apicystis bombi]]''; and [[microsporidia]]ns including ''[[Nosema bombi]]'' and ''[[Nosema ceranae]]''. The tree bumblebee ''[[Bombus hypnorum|B. hypnorum]]'' has spread into the United Kingdom despite hosting high levels of a [[nematode]] that normally interferes with queen bees' attempts to establish colonies.<ref>"[http://bumblebeeconservation.org/news/parasites-fail-to-halt-european-bumblebee-invasion-of-the-uk Parasites fail to halt European bumblebee invasion of the UK] {{Webarchive|url=https://web.archive.org/web/20160310133729/http://bumblebeeconservation.org/news/parasites-fail-to-halt-european-bumblebee-invasion-of-the-uk |date=10 March 2016 }}", Bumblebee Conservation Trust (retrieved 6 February 2015)</ref> [[Deformed wing virus]] has been found to affect 11% of bumblebees in Great Britain.<ref>"[http://bumblebeeconservation.org/news/new-study-shows-how-bumblebees-can-be-infected-by-honeybee-diseases New study shows how bumblebees can be infected by honeybee diseases] {{Webarchive|url=https://web.archive.org/web/20160304040846/http://bumblebeeconservation.org/news/new-study-shows-how-bumblebees-can-be-infected-by-honeybee-diseases |date=4 March 2016 }}", Bumblebee Conservation Trust (retrieved 6 February 2015)</ref>

Female bee moths (''[[Aphomia sociella]]'') prefer to lay their eggs in bumblebee nests. The ''A. sociella'' larvae will then feed on the eggs, larvae, and pupae left unprotected by the bumblebees, sometimes destroying large parts of the nest.<ref>{{Cite journal |last=Gambino |first=Parker |year=1995 |title=''Dolichovespula'' (Hymenoptera: Vespidae), Hosts of ''Aphomia sociella'' (L.) (Lepidoptera: Pyralidae) |journal=[[Journal of the New York Entomological Society]] |volume=103 |issue=2 |pages=165–169 |jstor=25010152}}</ref>

==Relationship to humans==

[[File:2005. Марка России stamp hi12612325014b2ce1752cdd2.jpg|thumb|upright|Bumblebees and human culture: ''Bombus anachoreta'' on a Russian postage stamp, 2005]]

===Agricultural use===

{{further|List of crop plants pollinated by bees}}

Bumblebees are important [[pollinator]]s of both crops and [[wildflower]]s.<ref>{{cite web |title=Modelling bee pollination: enter the 'flight arena' |url=http://www.foodsecurity.ac.uk/research/current/modelling-bee-pollination.html |website=Global Food Security |publisher=Biotechnology and Biological Sciences Research Council |access-date=11 February 2015 |archive-date=28 May 2017 |archive-url=https://web.archive.org/web/20170528140636/http://www.foodsecurity.ac.uk/research/current/modelling-bee-pollination.html }}</ref> Because bumblebees do not overwinter the entire colony, they do not stockpile honey, and therefore are not useful as honey producers. Bumblebees are increasingly cultured for agricultural use as pollinators, among other reasons because they can pollinate plants such as tomato in [[greenhouse]]s by buzz pollination whereas other pollinators cannot.<ref>{{cite web |url=http://www.nrdc.org/OnEarth/06sum/bees3.asp |title=NRDC: OnEarth Magazine, Summer 2006 – The Vanishing |access-date=9 July 2007}}</ref> Commercial production began in 1987, when Roland De Jonghe founded the Biobest company; in 1988 they produced enough nests to pollinate 40 hectares of tomatoes. The industry grew quickly, starting with other companies in the Netherlands. Bumblebee nests, mainly of buff-tailed bumblebees, are produced in at least 30 factories around the world; over a million nests are grown annually in Europe; Turkey is a major producer.<ref>{{harvnb|Goulson|2013|pages=169–170}}</ref>

Bumblebees are [[Northern Hemisphere]] animals. When [[red clover]] was introduced as a crop to New Zealand in the nineteenth century, it was found to have no local pollinators, and clover seed had accordingly to be imported each year. Four species of bumblebee from the United Kingdom were therefore imported as pollinators. In 1885 and 1886, the Canterbury Acclimatization Society brought in 442 queens, of which 93 survived and quickly multiplied. As planned, red clover was soon being produced from locally-grown seed.<ref name="Macdonald-2003"/> Bumblebees are also reared commercially to pollinate tomatoes grown in [[greenhouse]]s.<ref name="Biobees Bumblebee Pollination"/> The New Zealand population of [[buff-tailed bumblebee]]s began colonising [[Tasmania]], {{convert|1500|mi}} away, after being introduced there in 1992 under unclear circumstances.<ref>{{harvnb|Goulson|2013|pages=69–70}}</ref>

Some concerns exist about the impact of the international trade in mass-produced bumblebee colonies. Evidence from Japan<ref>{{cite journal |doi=10.1007/s10841-007-9071-z |title=Displacement of Japanese native bumblebees by the recently introduced ''Bombus terrestris'' (L.) (Hymenoptera: Apidae) |year=2007 |last1=Inoue |first1=Maki N. |last2=Yokoyama |first2=Jun |last3=Washitani |first3=Izumi |journal=Journal of Insect Conservation |volume=12 |issue=2 |pages=135–146|s2cid=33992235 }}</ref> and South America<ref>{{cite journal|doi=10.1007/s11829-013-9264-1 |title=Assessing the impact of the invasive buff-tailed bumblebee (''Bombus terrestris'') on the pollination of the native Chilean herb ''Mimulus luteus'' |year=2013 |last1=Esterio |first1=Gabriel |last2=Cares-Suárez |first2=Roxana |last3=González-Browne|first3=Catalina |last4=Salinas |first4=Patricia |last5=Carvallo|first5=Gastón |last6=Medel |first6=Rodrigo |journal=Arthropod-Plant Interactions|volume=7 |issue=4 |pages=467–474|bibcode=2013APInt...7..467E |hdl=10533/128436 |s2cid=2212551 |hdl-access=free }}</ref> indicates bumblebees can escape and naturalise in new environments, causing damage to native pollinators. Greater use of native pollinators, such as ''[[Bombus ignitus]]'' in China and Japan, has occurred as a result.<ref>{{Cite journal|title=Genetic Structure of Asian Populations of ''Bombus ignitus'' (Hymenoptera: Apidae)|journal=Journal of Heredity|date=January 2004|pmid=14757729|pages=46–52|volume=95|issue=1|doi=10.1093/jhered/esh008|first1=Z.-Y.|last1=Shao|first2=H.-X.|last2=Mao|first3=W.-J.|last3=Fu|first4=M.|last4=Ono|first5=D.-S.|last5=Wang|first6=M.|last6=Bonizzoni|first7=Y.-P.|last7=Zhang|doi-access=free}}</ref> In addition, mounting evidence indicates mass-produced bumblebees may also carry diseases, harmful to wild bumblebees<ref>{{cite journal |doi=10.1016/j.biocon.2005.11.013 |title=Plight of the bumble bee: Pathogen spillover from commercial to wild populations |year=2006 |last1=Colla |first1=Sheila R.|author1-link=Sheila Colla|last2=Otterstatter |first2=Michael C.|last3=Gegear|first3=Robert J. |last4=Thomson |first4=James D. |journal=Biological Conservation |volume=129|issue=4|pages=461–467|bibcode=2006BCons.129..461C }}</ref><ref name="Graystock-2013">{{cite journal|doi=10.1111/1365-2664.12134 |title=The Trojan hives: Pollinator pathogens, imported and distributed in bumblebee colonies |year=2013 |last1=Graystock |first1=Peter|last2=Yates |first2=Kathryn|last3=Evison |first3=Sophie E. F. |last4=Darvill |first4=Ben |last5=Goulson |first5=Dave |last6=Hughes |first6=William O. H. |editor1-last=Osborne |editor1-first=Juliet |journal=Journal of Applied Ecology |volume=50 |issue=5 |pages=1207–1215|bibcode=2013JApEc..50.1207G |s2cid=3937352 }}
* {{cite news |author=Victoria Gill |date=18 July 2013 |title=Imported bumblebees pose 'parasite threat' to native bees |work=BBC News |url=https://www.bbc.co.uk/news/science-environment-23347867}}</ref> and honeybees.<ref name="Graystock-2013" />

In Canada and Sweden, it has been shown that growing a mosaic of different crops encourages bumblebees and provides higher yields than does a monoculture of oilseed rape, despite the fact that the bees were attracted to the crop.<ref name="Goulson-2013b">{{harvnb|Goulson|2013|pages=169–172}}</ref>

===Population decline===

<!--this is very close to a COATRACK, should maybe become a separate article-->

Bumblebee species are declining in Europe, North America, and Asia due to a number of factors, including land-use change that reduces their food plants. In North America, pathogens are possibly having a stronger negative effect especially for the subgenus<!--source says ''sensu stricto'', "in the narrow sense"--> ''Bombus''.<ref>{{Cite journal |year=2009 |journal=Apidologie |volume=40 |issue=3 |pages=367–387 |url=http://www.nhm.ac.uk/research-curation/research/projects/bombus/Williams&Osborne09_review.pdf|doi=10.1051/apido/2009025 |title=Bumblebee vulnerability and conservation world-wide |first1=Paul H. |last1=Williams |first2=Juliet L. |last2=Osborne|s2cid=37080850 |id={{HAL|hal-00891048}}}}</ref> A major impact on bumblebees was caused by the mechanisation of agriculture, accelerated by the urgent need to increase food production during the Second World War. Small farms depended on horses to pull implements and carts. The horses were fed on clover and hay, both of which were permanently grown on a typical farm. Little artificial fertiliser was used. Farms thus provided flowering clover and flower-rich meadows, favouring bumblebees. Mechanisation removed the need for horses and most of the clover; artificial fertilisers encouraged the growth of taller grasses, outcompeting the meadow flowers. Most of the flowers, and the bumblebees that fed on them, disappeared from Britain by the early 1980s. The last native British short-haired bumblebee was captured near [[Dungeness (headland)|Dungeness]] in 1988.<ref>{{harvnb|Goulson|2013|pages=4–6}}</ref> This significant increase in pesticide and fertilizer use associated with the industrialization of agriculture has had adverse effects on the genus ''Bombus''. The bees are directly exposed to the chemicals in two ways: by consuming nectar that has been directly treated with pesticide, or through physical contact with treated plants and flowers. The species ''[[Bombus hortorum]]'' in particular has been found to be affected by the pesticides; their brood development has been reduced and their memory has been negatively affected. Additionally, pesticide use negatively affects colony development and size.<ref>{{Cite journal |url=https://hal.archives-ouvertes.fr/hal-00891048/file/hal-00891048.pdf |title=A newly recorded neogregarine (Protozoa, Apicomplexa), parasite in honey bees (''Apis mellifera'') and bumble bees (''Bombus'' spp.) |last1=Lipa |first1=J.J. |year=1992 |journal=Adipologie |last2=Triggiani |first2=O. |issue=6 |volume=23 |pages=533–536 |s2cid=56129905 }}</ref>

Bumblebees are in danger in many developed countries due to [[habitat destruction]] and collateral [[pesticide]] damage. The [[European Food Safety Authority]] ruled that three [[neonicotinoid]] pesticides ([[clothianidin]], [[imidacloprid]], and [[thiamethoxam]]) presented [[Imidacloprid effects on bee population|a high risk for bees]].<ref>{{Cite news |title=Pesticides: un risque enfin admis pour les abeilles |url=http://www.lemonde.fr/planete/article/2013/01/16/pesticides-un-risque-enfin-admis-pour-les-abeilles_1817630_3244.html |newspaper=Le Monde |date=16 January 2013|first=Stéphane |last= Foucart |lang=fr}}</ref> While most work on neonicotinoid toxicity has looked at honeybees, a study on ''B. terrestris'' showed that "field-realistic" levels of imidacloprid significantly reduced growth rate and cut production of new queens by 85%, implying a "considerable negative effect" on wild bumblebee populations throughout the developed world.<ref name="Whitehorn-2012">{{cite journal |last1=Whitehorn |first1=Penelope R.|last2=O'Connor |first2=Stephanie |last3=Wackers |first3=Felix L. |last4=Goulson |first4=Dave |title=Neonicotinoid pesticide reduces bumble bee colony growth and queen production |journal=Science |date=20 April 2012 |volume=336 |issue=6079 |pages=351–352 |doi=10.1126/science.1215025 |bibcode=2012Sci...336..351W |pmid=22461500|s2cid=2738787|doi-access=free }}</ref> Another study on ''B. terrestris'' had results suggesting that use of neonicotinoid pesticides can affect how well bumblebees are able to forage and pollinate. Foragers from bee colonies that had been affected by the pesticide took longer to learn to manipulate flowers and visited flowers with less nutritious pollen.<ref>{{Cite journal |last=Stanley |first=Dara |date=14 March 2016 |title=Chronic exposure to a neonicotinoid pesticide alters the interactions between bumblebees and wild plants |journal=[[Functional Ecology]] |doi=10.1111/1365-2435.12644 |pmid=27512241 |pmc=4950133 |volume=30 |issue=7 |pages=1132–1139 |bibcode=2016FuEco..30.1132S }}</ref>
In another study, chronic exposure in a laboratory setting to field-realistic levels of the neonicotinoid pesticide thiamethoxam did not affect colony weight gain or the number or mass of sexuals produced.<ref>{{cite journal |last1=Stanley |first1=Dara A. |last2=Raine |first2=Nigel E. |title=Bumblebee colony development following chronic exposure to field-realistic levels of the neonicotinoid pesticide thiamethoxam under laboratory conditions |journal=Scientific Reports |year=2017 |page=8005 |doi=10.1038/s41598-017-08752-x |pmid=28808317|pmc=5556064 |volume=7 |issue=1 |bibcode=2017NatSR...7.8005S}}</ref> Low levels of neonicotinoids can reduce the number of bumblebees in a colony by as much as 55%, and cause dysfunction in the bumblebees' brains. The Bumblebee Conservation Trust considers this evidence of reduced brain function "particularly alarming given that bumblebees rely upon their intelligence to go about their daily tasks."<ref>{{cite web|title=Bumblebee brains affected by neonicotinoids|url=http://bumblebeeconservation.org/news/bumblebee-brains-affected-by-neonicotinoids |publisher=[[Bumblebee Conservation Trust]] |date=3 February 2014 |quote=New research has emerged from the Universities of Dundee and St. Andrews which shows that accepted environmental levels of neonicotinoids impair bumblebee brain functionality and consequently negatively affect the performance of whole colonies. |archive-url=https://web.archive.org/web/20150219162725/http://bumblebeeconservation.org/news/bumblebee-brains-affected-by-neonicotinoids |archive-date=19 February 2015}} Research was published in the Journal of the Federation of American Societies for Experimental Biology by Chris Connolly and others.</ref>

Of 19 species of native nestmaking bumblebees and six species of cuckoo bumblebees formerly widespread in Britain,<ref>{{Cite book |chapter-url=http://drkaae.com/content/chapter-18-bees-wasps-and-ants |first=Richard |last=Kaae |chapter=Bees, Wasps and Ants |date=nd |title=Insect & Civilization Part 2 |access-date=23 December 2013 |archive-url=https://web.archive.org/web/20131224121927/http://drkaae.com/content/chapter-18-bees-wasps-and-ants |archive-date=24 December 2013}}</ref> three have been extirpated,<ref>{{cite web |url=https://www.sciencedaily.com/releases/2006/07/060728162546.htm |title=Scientists map the flight of the bumblebee |website=Science Daily |date=28 July 2006 |author=University of Newcastle-upon-Tyne |author-link=Newcastle University}}</ref><ref>{{cite journal |last=Harman |first=Alan |title=Bumblebee Shortage |journal=Bee Culture |volume=59 |date=July 2003}}</ref> eight are in [[pollinator decline|serious decline]], and only six remain widespread.<ref>{{cite journal |url=http://www.nhm.ac.uk/research-curation/projects/bombus/decline.html |last=Williams |first=Paul H. |year=1986 |title=Environmental change and the distributions of British bumble bees (''Bombus'' Latr.) |journal=Bee World |volume=67 |issue=2 |pages=50–61 |doi=10.1080/0005772x.1986.11098871}}</ref> Similar declines have been reported in Ireland, with four species designated [[Endangered species|endangered]], and another two considered [[Vulnerable species|vulnerable]] to extinction.<ref>{{cite web |last1=Fitzpatrick |first1=U. |first2=T. E. |last2=Murray |first3=A. |last3=Byrne |first4=R. J. |last4=Paxton  |first5=M. J. F. |last5=Brown |year=2006 |url=http://www.npws.ie/en/media/NPWS/Publications/Redlists/Media,4860,en.pdf |title=Regional red list of Irish Bees |publisher=Report to National Parks and Wildlife Service (Ireland) and Environment and Heritage Service (N. Ireland)}}{{dead link|date=June 2014}}</ref> A decline in bumblebee numbers could cause large-scale changes to the countryside, resulting from inadequate pollination of certain plants.<ref name="Geographical-2008">{{cite journal |year=2008 |title=World's first bumblebee sanctuary creates a buzz |journal=Geographical |volume=80 |issue=10 |page=8 |url=http://findarticles.com/p/articles/mi_hb3120/is_10_80/ai_n30892916/}}</ref>

Some bumblebees native to North America are also vanishing, such as ''[[Bombus balteatus]]'',<ref>{{Cite journal |last1=Miller-Struttmann |first1=Nicole E. |last2=Geib |first2=Jennifer C. |last3=Franklin |first3=James D. |last4=Kevan |first4=Peter G. |last5=Holdo |first5=Ricardo M.|last6=Ebert-May |first6=Diane |last7=Lynn |first7=Austin M. |last8=Kettenbach |first8=Jessica A. |last9=Hedrick |first9=Elizabeth |display-authors=6 |date=2015-09-25 |title=Functional mismatch in a bumble bee pollination mutualism under climate change |journal=Science |volume=349 |issue=6255 |pages=1541–1544|doi=10.1126/science.aab0868|pmid=26404836 |bibcode=2015Sci...349.1541M |s2cid=46616411 |doi-access=free}}</ref> ''[[Bombus terricola]]'',<ref>{{cite journal |last1=Wong |first1=Lisa |last2=Cameron |first2=Sydney |last3=Favret |first3=Colin |last4=Jennifer |first4=Grixti |title=Decline of bumble bees (''Bombus'') in the North American Midwest |journal=Biological Conservation |year=2009 |volume=142 |issue=1 |pages=75–84 |doi=10.1016/j.biocon.2008.09.027|bibcode=2009BCons.142...75G }}</ref> ''[[Bombus affinis]]'',<ref name="Flesher-2017">{{cite news|last1=Flesher|first1=Lohn|title=Rusty Patched Bumblebee Declared Endangered|url=https://abcnews.go.com/US/wireStory/apnewsbreak-rusty-patched-bumblebee-declared-endangered-44677209 |agency=APNews |work=[[ABC News (United States)|ABC News]] |date=10 January 2017}}</ref><ref>{{cite web |title=Fact Sheet Rusty Patched Bumble Bee (''Bombus affinis'')|url=https://www.fws.gov/midwest/endangered/insects/rpbb/factsheetrpbb.html |website=Endangered Species |publisher=[[United States Fish and Wildlife Service]] |access-date=10 January 2017}}</ref> and ''[[Bombus occidentalis]]''; one, ''[[Bombus franklini]]'', may be extinct.<ref>{{cite web |url=http://www.xerces.org/bumblebees/ |title=Bumble Bee Conservation |publisher=The Xerces Society for Invertebrate Conservation |access-date=20 June 2010}}</ref> In South America, ''Bombus bellicosus'' was [[Local extinction|extirpate]]d in the northern limit of its distribution range, probably due to intense land use and climate change effects.<ref>{{cite journal |last1=Martins |first1=Aline C. |last2=Melo |first2=Gabriel A. R. |title=Has the bumblebee ''Bombus bellicosus'' gone extinct in the northern portion of its distribution range in Brazil? |journal=Journal of Insect Conservation |year=2009 |volume=14 |issue=2 |pages=207–210 |doi=10.1007/s10841-009-9237-y |s2cid=31976881 }}</ref>

===Conservation efforts===

[[File:Vallhumla Hane06178.jpg|thumb|left|upright=0.9|Drone short-haired bumblebee, ''[[Bombus subterraneus]]''. The species was successfully reintroduced to England from Sweden.]]

In 2006, the bumblebee researcher [[Dave Goulson]] founded a registered charity, the [[Bumblebee Conservation Trust]], to prevent the extinction "of any of the UK's bumblebees."<ref>{{cite web |url=http://bumblebeeconservation.org/about-us/ |title=About us |publisher=Bumblebee Conservation Trust |access-date=10 May 2014 |archive-date=19 May 2014 |archive-url=https://web.archive.org/web/20140519033435/http://bumblebeeconservation.org/about-us/ }}</ref><ref name="Barkham-2013">{{cite news |last1=Barkham |first1=Patrick |title=A Sting in the Tale by Dave Goulson – review |url=https://www.theguardian.com/books/2013/may/18/sting-tale-dave-goulson-review |access-date=26 June 2014|work=The Guardian |issue=18 May 2013}}</ref> In 2009 and 2010, the Trust attempted to reintroduce the short-haired bumblebee, ''[[Bombus subterraneus]]'', which had become extinct in Britain, from the British-derived populations surviving in New Zealand from their introduction there a century earlier.<ref>{{harvnb|Goulson|2013|pages=1–14, 227–241}}</ref> From 2011, the Trust, in partnership with [[Natural England]], Hymettus and the [[Royal Society for the Protection of Birds|RSPB]], has reintroduced short-haired bumblebee queens from [[Skåne]] in southern Sweden to restored flower-rich meadows at Dungeness in Kent. The queens were checked for [[mites]] and [[American foulbrood]] disease. Agri-environment schemes spread across the neighbouring area of [[Romney Marsh]] have been set up to provide over 800 hectares of additional flower-rich habitat for the bees. By the summer of 2013, workers of the species were found near the release zone, proving that nests had been established. The restored habitat has produced a revival in at least five "Schedule 41 priority" species: the ruderal bumblebee, ''[[Bombus ruderatus]]''; the red-shanked carder bee, ''[[Bombus ruderarius]]''; the shrill carder bee, ''[[Bombus sylvarum]]''; the brown-banded carder bee, ''[[Bombus humilis]]'' and the moss carder bee, ''[[Bombus muscorum]]''.<ref>{{cite web|title=The Short-haired bumblebee reintroduction |url=http://bumblebeeconservation.org/about-us/case-study/short-haired-bumblebee-reintroduction/ |publisher=Bumblebee Conservation Trust |access-date=19 February 2015 |archive-url=https://web.archive.org/web/20150216002921/http://bumblebeeconservation.org/about-us/case-study/short-haired-bumblebee-reintroduction/ |archive-date=16 February 2015 }}</ref>

The world's first bumblebee sanctuary was established at Vane Farm in the [[Loch Leven (Kinross)|Loch Leven National Nature Reserve]] in Scotland in 2008.<ref name="Geographical-2008"/> In 2011, London's [[Natural History Museum, London|Natural History Museum]] led the establishment of an [[International Union for Conservation of Nature]] Bumblebee Specialist Group, chaired by Dr. Paul H. Williams,<ref name="Natural History Museum">{{Cite web |url=http://www.nhm.ac.uk/research-curation/life-sciences/terrestrial-invertebrates/research/hymenoptera-research/bumble-bee-research/bumblebee-specialist-group/index.html |archive-url=https://web.archive.org/web/20140104105733/http://www.nhm.ac.uk/research-curation/life-sciences/terrestrial-invertebrates/research/hymenoptera-research/bumble-bee-research/bumblebee-specialist-group/index.html |archive-date=2014-01-04 |title=Bumblebee Specialist Group |access-date=23 December 2013 |website=Natural History Museum |location=London}}</ref> to assess the threat status of bumblebee species worldwide using [[Red List]] criteria.<ref>{{Cite web |url=http://cmsdata.iucn.org/downloads/bumblebee_sg_proofed.pdf |title=2011 Update |publisher=IUCN |access-date=7 October 2012 |archive-url=https://web.archive.org/web/20121203034020/http://cmsdata.iucn.org/downloads/bumblebee_sg_proofed.pdf |archive-date=3 December 2012 }}</ref>

Bumblebee conservation is in its infancy in many parts of the world, but with the realization of the important part they play in pollination of crops, efforts are being made to manage farmland better. Enhancing the wild bee population can be done by the planting of wildflower strips, and in New Zealand, bee nesting boxes have achieved some success, perhaps because there are few burrowing mammals to provide potential nesting sites in that country.<ref name="Goulson-2013b"/>

===Misconception about flight===

{{anchor|Flight}}

[[File:AD2009Aug08 Bombus pratorum.jpg|thumb|right|A widely believed falsehood holds that scientists proved bumblebees to be incapable of flight.<ref>{{cite web |url=http://www.sciencenews.org/view/generic/id/5400/title/Math_Trek__Flight_of_the_Bumblebee|title=Flight of the Bumblebee |author=Ivars Peterson |date=11 September 2004 |work=[[Science News]]}} "the venerable line about scientists having proved that a bumblebee can't fly appears regularly in magazine and newspaper stories. It's also the kind of item that can come up in a cocktail party conversation when the subject turns to science or technology. [...] Often, the statement is made in a distinctly disparaging tone aimed at putting down those know-it-all scientists and engineers who are so smart yet can't manage to understand something that's apparent to everyone else. [...] the story has had remarkable staying power, and the myth persists that science says a bumblebee can't fly. Indeed, this myth has taken on a new life of its own as a piece of "[[urban legend|urban folklore]]" on the Internet."</ref>|alt=A bumblebee landing on a purple flower]]

{{further|Insect flight}}

According to 20th-century [[folklore]], the laws of [[aerodynamics]] prove the bumblebee should be incapable of [[flight]], as it does not have the capacity (in terms of wing size or beats per second) to achieve flight with the degree of [[wing loading]] necessary.<ref name="The secrets of bee flight"/>

{{blockquote|'Supposedly someone did a back of the envelope calculation, taking the weight of a bumblebee and its wing area into account, and worked out that if it only flies at a couple of metres per second, the wings wouldn't produce enough lift to hold the bee up,' explains Charlie Ellington, Professor of Animal Mechanics at Cambridge University.<ref name="The secrets of bee flight">{{cite web |url=http://www.physics.org/featuredetail.asp?id=32 |title=The secrets of bee flight |access-date=12 February 2015 |archive-url=https://web.archive.org/web/20150107175747/http://www.physics.org/featuredetail.asp?id=32 |archive-date=7 January 2015}}</ref>}}

The origin of this claim has been difficult to pin down with any certainty. [[John H. McMasters]] recounted an anecdote about an unnamed Swiss aerodynamicist at a dinner party who performed some rough calculations and concluded, presumably in jest, that according to the equations, bumblebees cannot fly.<ref>{{cite journal |last=McMasters |first=John H. |title=The flight of the bumblebee and related myths of entomological engineering |journal=American Scientist |volume=77 |issue=2 |date=March–April 1989 |pages=146–169 |bibcode=1989AmSci..77..164M}} cited in {{cite book |author=Jay Ingram |title=The Barmaid's Brain |publisher=[[Aurum Press]] |year=2001 |pages=91–92 |isbn=978-1-85410-633-9}}</ref>

In later years, McMasters backed away from this origin, suggesting there could be multiple sources, and stating that the earliest he had found was a reference in the 1934 book ''{{lang|fr|Le Vol des Insectes}}'' by French entomologist [[Antoine Magnan]] (1881–1938). Magnan had applied the equations of [[drag (physics)|air resistance]] to insects, giving the result that their flight would be impossible, but "One shouldn't be surprised that the results of the calculations don't square with reality".<ref>{{cite book |first=Jay |last=Ingram |title=The Barmaid's Brain |publisher=[[Aurum Press]] |year=2001 |pages=91–92 |isbn=978-1-85410-633-9}}</ref> The following passage appears in the introduction to ''Le Vol des Insectes'':<ref name="Magnan-1934">{{cite book |last=Magnan |first=Antoine |title=Le Vol des Insectes |date=1934 |publisher=Hermann |url=https://books.google.com/books?id=RoXgOgAACAAJ}}</ref>

{{verse translation|lang=fr|Tout d'abord poussé par ce qui se fait en aviation, j'ai appliqué aux insectes les lois de la résistance de l'air, et je suis arrivé avec M. Sainte-Laguë à cette conclusion que leur vol est impossible.|First prompted by what is done in aviation, I applied the laws of air resistance to insects, and I arrived, with Mr. Sainte-Laguë, at this conclusion that their flight is impossible.}}

Magnan refers to his assistant [[André Sainte-Laguë]].<ref>"The bumblebee story can be traced back to a 1934 book by entomologist Antoine Magnan, who refers to a calculation by his assistant André Sainte-Laguë, who was an engineer. The conclusion was presumably based on the fact that the maximum possible lift produced by aircraft wings as small as a bumblebee's wings and traveling as slowly as a bee in flight would be much less than the weight of a bee."{{Cite journal |pmid=11396342 |year=2001 |last1=Dickinson |first1=M. |title=Solving the mystery of insect flight |journal=Scientific American |volume=284 |issue=6 |pages=48–57 |doi=10.1038/scientificamerican0601-48 |bibcode=2001SciAm.284f..48D}}</ref> Some credit physicist [[Ludwig Prandtl]] (1875–1953) of the [[University of Göttingen]] in Germany with popularizing the idea. Others say Swiss gas dynamicist [[Jakob Ackeret]] (1898–1981) did the calculations.<ref>{{cite web |website=Snopes |title=Bumblebees Can't Fly |date=15 March 2013 |url=http://www.snopes.com/science/bumblebees.asp |access-date=9 April 2013}}</ref>

[[File:Bumble Bee in flight.JPG|thumb|Bumblebee in flight. It has its tongue extended and a laden pollen basket.]]

The calculations that purported to show that bumblebees cannot fly are based upon a simplified linear treatment of [[oscillating]] [[airfoil|aerofoils]]. The method assumes small amplitude oscillations without flow separation. This ignores the effect of [[Stall (flight)#Dynamic stall|dynamic stall]] (an airflow separation inducing a large [[vortex]] above the wing), which briefly produces several times the lift of the aerofoil in regular flight. More sophisticated aerodynamic analysis shows the bumblebee can fly because its wings encounter dynamic stall in every [[oscillation]] cycle.<ref>{{cite news |title=Bumblebees finally cleared for takeoff |url=https://www.news.cornell.edu/releases/March00/APS_Wang.hrs.html |newspaper=[[Cornell Chronicle]] |date=20 March 2000}}</ref>

The evolutionary biologist [[John Maynard Smith]] pointed out that bumblebees would not be expected to sustain flight, as they would need to generate too much power given their tiny wing area. However, in aerodynamics experiments with other insects, he found that [[viscosity]] at the scale of small insects meant even their small wings can move a very large volume of air relative to their size, and this reduces the power required to sustain flight by an order of magnitude.<ref>{{cite web |url=http://www.vega.org.uk/video/programme/84 |title=Flight in Birds and Aeroplanes – Science Video |last=Maynard Smith |first=John |author-link=John Maynard Smith |access-date=20 June 2010}}</ref>

===In music and literature===

{{listen|filename=Rimsky-Korsakov - flight of the bumblebee.oga|title=Flight of the Bumblebee|description=[[Nikolai Rimsky-Korsakov]]'s 1900 ''[[Flight of the Bumblebee]]'' performed by the US Army Band |format=[[Ogg]]}}

The orchestral interlude ''[[Flight of the Bumblebee]]'' was composed (c. 1900) by [[Nikolai Rimsky-Korsakov]]. It represents the turning of Prince Guidon into a bumblebee so he can fly away to visit his father, Tsar Saltan, in the opera ''[[The Tale of Tsar Saltan (opera)|The Tale of Tsar Saltan]]'',<ref>{{cite book |title=A history of Russian music: from Kamarinskaya to Babi Yar |last=Maes |first=Francis |year=2002 |publisher=[[University of California Press]] |isbn=978-0-520-21815-4 |page=[https://archive.org/details/historyofrussian0000maes/page/191 191] |url=https://archive.org/details/historyofrussian0000maes |url-access=registration |access-date=3 April 2010}}</ref> although the music may reflect the flight of a [[Calliphoridae|bluebottle]] rather than a bumblebee.<ref>{{cite book |title=The science of music |author=Maconie, Robin |year=1997 |publisher=[[Oxford University Press]] |isbn=978-0-19-816648-1 |page=184 |url=https://books.google.com/books?id=i7-xLzn2ZS8C}}</ref> The music inspired [[Walt Disney]] to feature a bumblebee in his 1940 animated musical ''[[Fantasia (1940 film)|Fantasia]]'' and have it sound as if it were flying in all parts of the theater. This early attempt at "[[surround sound]]" was excluded from the film in later showings.<ref>{{cite book |title=Surround sound: up and running |author=Holman, Tomlinson |year=2007 |publisher=Focal Press |isbn=978-0-240-80829-1 |pages=3–4 |url=https://books.google.com/books?id=nnLAD1N_MNIC}}</ref> 

In 1599, during the reign of [[Elizabeth I of England|Queen Elizabeth I]], someone, possibly Tailboys Dymoke, published ''Caltha Poetarum: Or The Bumble Bee'', under the pseudonym "T. Cutwode".<ref>{{cite book |title=Caltha poetarum: or The bumble bee. Composed by T. Cutwode Esquyre. |date=25 July 1599 |url=http://quod.lib.umich.edu/e/eebo/A19732.0001.001?view=toc |publisher=University of Michigan Libraries |access-date=11 February 2015}}</ref> This was one of nine books [[censorship|censored]] under the [[Bishops' Ban of 1599|Bishops' Ban]] issued by the Archbishop of Canterbury [[John Whitgift]] and the Bishop of London [[Richard Bancroft]].<ref>{{cite web |title=Caltha Poetarum |url=http://www.banned-books.info/book-content.php?key=220 |website=Banned Books |access-date=11 February 2015 |url-status=usurped |archive-url=https://web.archive.org/web/20150211180241/http://www.banned-books.info/book-content.php?key=220 |archive-date=11 February 2015}}</ref>

[[Emily Dickinson]] made a bumblebee the subject of her parody of [[Isaac Watts]]'s well-known poem about honeybees, "How Doth the Little Busy Bee" (1715). Where Watts wrote "How skilfully she builds her cell! How neat she spreads the wax!",<ref>{{cite web |last=Watts |first=Isaac |author-link=Isaac Watts |title=How Doth the Little Busy Bee |url=http://www.poets.org/poetsorg/poem/how-doth-little-busy-bee |website=Poets.org|year=1715|access-date=13 February 2015}}</ref> Dickinson's poem, "The Bumble-Bee's Religion" (1881), begins "His little Hearse-like Figure / Unto itself a Dirge / To a delusive Lilac / The vanity divulge / Of Industry and Morals / And every righteous thing / For the divine Perdition / of Idleness and Spring." The letter is said to have enclosed a dead bee.<ref name="Morgan-2010">{{cite book |last=Morgan |first=Victoria N. |title=Emily Dickinson and Hymn Culture: Tradition and Experience |url=https://books.google.com/books?id=8qE1bCYzkd4C&pg=PA183 |year=2010 |publisher=Ashgate |isbn=978-0-7546-6942-5 |pages=183–184}}</ref><ref>{{cite book |last=Dickinson |first=Emily |author-link=Emily Dickinson |title=The Bumble-Bee's Religion, in a letter to Gilbert Dickinson, 1881 |work=The Letters of Emily Dickinson |page=712 |date=1986 |url=https://books.google.com/books?id=Vy7VIpug6Q8C&pg=PA701 |publisher=[[Harvard University Press]] |isbn=978-0-674-52627-3 }}</ref>

In 1847, [[Ralph Waldo Emerson]] published his poem "[[s:The Humble-Bee|The Humble-Bee]]".<ref>{{cite book |last=Emerson |first=Ralph Waldo |author-link=Ralph Waldo Emerson |title=Poems |date=1847 |publisher=James Munroe and Company |location=Cambridge, Massachusetts |url=https://en.wikisource.org/wiki/The_Humble-Bee |chapter=The Humble-Bee}}</ref>

The entomologist [[Otto Plath]] wrote ''Bumblebees and Their Ways'' in 1934.<ref>{{cite web|last1=Steinberg |first1=Peter K. |title=Biography |url=http://www.sylviaplath.info/biography.html |publisher=SylviaPlath.info |access-date=19 February 2015}}</ref> His daughter, the poet [[Sylvia Plath]], wrote a group of poems about bees late in 1962, within four months of her suicide,<ref>{{cite web |title=Sylvia Plath and the Bees |url=https://dublinbees.com/sylvia-plath-and-the-bees/|publisher=The County Dublin Beekeepers' Association |access-date=19 February 2015}}</ref> transforming her father's interest into her poetry.<ref name="Kirk-2004">{{cite book |last=Kirk |first=Connie Ann |title=Sylvia Plath: A Biography |url=https://books.google.com/books?id=NBlJYGHVESwC&pg=PA14 |date=1 January 2004 |publisher=[[Greenwood Publishing Group]] |isbn=978-0-313-33214-2 |page=14}}</ref>

[[File:Moses Harris00.jpg|thumb|upright|Bumblebees of different species illustrated by [[Moses Harris]] in his 1782 ''Exposition of English Insects'']]

The scientist and illustrator [[Moses Harris]] (1731–1785) painted accurate watercolour drawings of bumblebees in his ''An Exposition of English Insects Including the Several Classes of Neuroptera, Hymenoptera, & Diptera, or Bees, Flies, & Libellulae (1776–80)''.<ref>{{Cite book |title=Exposition of English insects |publisher=WorldCat |year=1782 |oclc=15094019 }}</ref>

The surname [[Albus Dumbledore|Dumbledore]] in the [[Harry Potter]] series (1997–2007) is an old name for bumblebee.<ref name="Dumbledor-1913">{{cite encyclopedia |year=1913 |title=Dumbledor |encyclopedia=Merriam–Webster |url=http://machaut.uchicago.edu/cgi-bin/WEBSTER.sh?WORD=dumbledor |archive-url=https://web.archive.org/web/20151017052743/http://machaut.uchicago.edu/cgi-bin/WEBSTER.sh?WORD=dumbledor |archive-date=17 October 2015}}</ref> [[J. K. Rowling]] said the name "seemed to suit the headmaster, because one of his passions is music and I imagined him walking around humming to himself".<ref>{{cite book |last1=Sexton |first1=Colleen A. |title=J. K. Rowling |date=1 October 2007 |publisher=Twenty-First Century Books |isbn=978-0-8225-7949-6 |page=46 |url=https://books.google.com/books?id=gX2lAgAAQBAJ&pg=PA46}}</ref> [[J. R. R. Tolkien]], in his poem ''[[Errantry]]'', used the term Dumbledor for a bumblebee.<ref>{{cite book |editor-last1=Scull |editor-first1=Christina |editor1-link=Christina Scull |editor-last2=Hammond |editor-first2=Wayne G. |editor2-link=Wayne G. Hammond |year=2014 |title=[[The Adventures of Tom Bombadil]] |publisher=[[HarperCollins]] |isbn=978-0-00-755727-1 |page=166}}</ref> Among [[Beatrix Potter]]'s "little books", Babbity Bumble and other members of her nest appear in her 1910 ''[[The Tale of Mrs. Tittlemouse]]''.<!--that's already a citation--><ref name="Jones 2010"/>

==See also==

* ''[[Ophrys bombyliflora]]'' – the bumblebee orchid
* [[Melittology]] (also known as apiology) – the study of bees

==Notes==

{{notelist}}

==References==

{{reflist|30em}}

==Sources==

* [[Dave Goulson|Goulson, Dave]]. ''Bumblebees: Their Behaviour and Ecology'', 2003. [[Oxford University Press]]. {{ISBN|0-19-852607-5}}.
* {{cite book |last=Goulson |first=Dave |author-link=Dave Goulson |title=A Sting in the Tale |publisher=Jonathan Cape |year=2013}}
* {{cite web |last=Macdonald |first=Murdo |url=http://www.snh.org.uk/pdfs/publications/naturallyscottish/bumblebees.pdf |title=Bumblebees |publisher=[[Scottish Natural Heritage]] |year=2003 |archive-url=https://web.archive.org/web/20160303221831/http://www.snh.org.uk/pdfs/publications/naturallyscottish/bumblebees.pdf |archive-date=3 March 2016 }}
* Macdonald, Murdo & Nisbet, G. ''[http://www.hbrg.org.uk/BeeAtlas/DownloadBeeAtlas.html Highland Bumblebees: Distribution, Ecology and Conservation]''.<!--free online after filling in form--> [http://www.hbrg.org.uk HBRG], 2006. {{ISBN|0-9552211-0-2}}. – [http://www.hbrg.org.uk/MainPages/Supplement2.pdf Supplement 2] (2007).
* [[Charles Duncan Michener|Michener, C.D.]] ''The Bees of the World''. [[Johns Hopkins University Press]], 2000.
* Schweitzer, Dale F. et al. ''[https://purl.fdlp.gov/GPO/gpo36661 Conservation and Management of North American Bumble Bees]''. Washington D.C.: [[United States Forest Service|U.S. Forest Service]], 2012.
<!--don't add sources here unless you cite them in the article-->

==External links==
* [http://www.nhm.ac.uk/research-curation/projects/bombus/ Bumblebees of the world – find species by region, species groups, colour pattern], nhm.ac.uk
* [http://www.bumblebeeconservation.org/ Bumblebee Conservation Trust]
* [http://www.iucn.org/about/work/programmes/species/who_we_are/ssc_specialist_groups_and_red_list_authorities_directory/invertebrates/bumblebee_specialist_group/ IUCN's Bumblebee Specialist Group]
* [http://www.discoverlife.org/mp/20q?guide=Bombus ''Bombus'' Identification Guide], [http://www.discoverlife.org/mp/20q?search=Bombus Discover Life: List of Species], [http://www.discoverlife.org/mp/20m?kind=Bombus_ Worldwide Species Map].
* [http://www.caltech.edu/news/deciphering-mystery-bee-flight-1075 Deciphering the Mystery of Bee Flight]

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