Skip to main content
Cherry blossom by Bex Cartwright

Pollinators in sweet cherry orchards

A cherry blossom tree bloom

by Zeus Mateos Fierro

The full bloom of cherry blossoms is a beautiful and yet ephemeral event that lasts about three weeks (typically from mid-April to early May). Numerous blossoms are available to pollinators, but resources are scarce for them in orchards after the blossom period. Cherry orchards have evolved in the last decades from the traditional open orchards with large trees to modern protected orchards with a smaller but greater number of trees.

However, pollinators are still needed to pollinate cherry blossoms and underpin yields, particularly since most of the varieties are self-incompatible and cross-pollination is required. Consequently, growers are highly reliant on managed pollinators. For the last three years, I have been researching pollination and pest regulation in commercial sweet cherry orchards in the West Midlands for my PhD at the University of Worcester. I have investigated the enhancement of wild pollinating insects, including bees, hoverflies, and butterflies through wildflowers.

Newly created wildflower habitats, with native perennial plant species, were established in the alleyways between rows of cherry trees to increase sustainable and resilient pollination. This is the first time that such an approach has been investigated under protective cropping, and could involve important benefits for the sweet cherry industry. A key aim of my project was to investigate what pollinators visited cherry blossoms and how effective they were delivering pollination services. I also investigated what pollinating insects used the wildflowers after the blossom period until late September. The study was funded by the University of Worcester, Waitrose & Partners, and Berry Gardens, in partnership with the University of Reading and NIAB EMR.

As with many fruit crops, cherries are typically pollinated by the western honeybee (Apis mellifera), but increasingly buff-tailed bumblebees (Bombus terrestris) have been used. Honeybee hives are hired and bumblebee nest boxes are bought, so that there are enough pollinators to support production. However, wild pollinators might be more efficient at pollinating cherry blossoms compared to managed pollinators. During our transect surveys in cherry orchards across the three-year study, we recorded a total of 19,738 pollinating insects, of which14,724 were recorded during the blossom period and 5,014 after. Managed pollinators were the most abundant with 6,502 honeybees, and 5,296 buff-tailed bumblebees recorded. Hoverflies were the most abundant wild pollinator guild, which accounted for 4,760 individuals, followed by 1,879 bumblebees, 1069 solitary bees, and 232 butterflies.

In total, 104 different pollinator species were recorded! This included one species of honeybee, ten bumblebee species, 33 species of solitary bee, 48 species of hoverfly, and 12 butterfly species. These figures show how reliant growers are on managed pollinators. However, despite the greater abundance of these, wild bumblebees (queens during the cherry blossom period) and solitary bees were more effective pollinating cherry blossoms, since they frequently contacted cherry stigmas and flew often between rows, enhancing cross-pollination.

Throughout my study, I found that wildflower strips increased the abundance and richness of pollinating insects, and therefore pollinator diversity, compared to unsown conventional alleyways. This led to an increase in fruit set. Although it takes time for benefits for growers to materialize, our approach has created a range of possibilities for growers to produce sweet cherries more sustainably. For example, wildflower habitats also provide resources to other beneficial insects (e.g. natural enemies), which can deliver pest regulation services throughout the growing season. The inclusion of wildflowers in the orchards also means the orchards can support pollinators throughout the year and not just during the cherry blossom period. The wildflower habitats are also an important tool for conservation, given that many pollinator species continue to decline.

Bombus kluanensis by Harry Taylor, NHM digital imaging unit

Bumblebees of the World Blog Series… #12 Bombus kluanensis

Holotype queen of Bombus kluanensis

by Paul Williams, researcher at the Natural History Museum, London, and Darryl Cox, Senior Science & Policy Officer.

Our Bumblebees of the World journey ends in the Arctic Circle with one of the newest described bumblebee species to science, Bombus kluanensis, named after the Kluane Lake in the Yukon region of Canada.

Latin name: Bombus kluanensis

Common name/s: Kluane bumblebee

Colour pattern: Queens, workers and males broadly similar: mainly yellow, with a black band across the thorax at the wings, abdomen is yellow haired at the top, followed by a black tail or occasionally a black tail with an orange tip.

Favoured flowers: Unknown

Global region: Arctic

Geographic distribution: North America: Canada (Yukon) and U.S. (Alaska)

Conservation status: Not assessed

It is not very often in the 21st century that new bumblebee species are discovered. However thanks to molecular and morphological analysis by the world’s leading bumblebee experts, a brand new species was described to science in 2016. Bombus kluanensis, originally thought to be a variation of Bombus neoboreus was found to be genetically and morphologically distinct. Both species belong to the subgenus group known as Alpinobombus, an interesting group of bumblebees that can occur as far north in the Arctic as there are food plants available. Those that do inhabit the Arctic Circle are adapted to live with especially short cold summers and have larger bodies and longer hair to keep them warm. They might even be better at thermoregulation than other bumblebees, although this has yet to be investigated.

So how did Bombus kluanensis remain undiscovered for so long? In a recent assessment of the Alpinobombus group, Paul Williams and his colleagues note that the first specimens of this bumblebee species were two queens collected from the Klutlan Glacier in the Yukon, Canada, in 1913. It was not until 60 years later that these specimens were assigned the name Bombus strenuus (which would later be known as the Active bumblebee, Bombus neoboreus) in a review of bumblebees from the Western Hemisphere. A more extensive collecting effort was carried out in 1971 and 1972, in which 18 queens and over 200 workers were collected from Kluane, Yukon. These were also assigned the name Bombus stenuus upon review in 1986. They now reside in the Smithsonian collection in Washington DC, where they remained misidentified until 2015, when Paul re-examined them. What prompted Paul to re-examine these specimens was his discovery that two specimens, collected from the Saint Elias Mountains (Yukon) in 2010 by his colleague, Canadian Zoologist, Syd Cannings, were genetically distinct from other Bombus neoboreus. The DNA barcodes of the new species was later matched to other specimens found in the Alaska mountain range in the Denali National Park, Alaska, as well as the historical records from the Kluane region.

Since the discovery, Williams and Cannings have worked to find useful comparable morphological features which can be used to differentiate the Kluane bumblebee from the Active bumblebee. Some of the most useful features are a more extensively longer than broad cheek, more yellow hair with black hairs intermixed along the top two thirds of the thorax (the same area is very pale with few black hairs in Bombus neoboreus), a broad yellow band at the bottom of the thorax, and more black than orange hairs on the abdomen, compared to Bombus neoboreus.

The Kluane bumblebee has not yet had its conservation status assessed, however Syd, who works as Species at Risk Biologist for the Canadian Wildlife Service, explained some of the work that is going on in the region which should benefit the species:

“The government of Canada is interested in increasing the area of their protected areas, and doing this in a rational way that protects biodiversity, so they have given funding to the Wildlife Conservation Society to use the IUCN Key Biodiversity Area (KBA) protocol to delineate KBAs in Canada. The Yukon was selected as a test case for this protocol and we had a 2-day workshop in Whitehorse last month. Part of that protocol looks at endemic species where KBAs could hold more than 10% of the global population of a species (or in the case of a national KBA, more than 10% of the national population). One of the KBAs we looked at was Kluane National Park itself, and Bombus kluanensis was one of the endemic species that we used to justify mapping a KBA using the park boundaries. There are a number of species that are restricted to that region, presumably because of glacial refugia there during the Pleistocene.

Another area that we are interested in is Asi Keyi, a territorial park proposal to the north of Kluane, where we found Bombus kluanensis during a brief visit a few years ago. Yukon Parks is planning to fly into that area this summer, and we hope to hitch a ride in with them to look for endemic plants and insects, including Bombus kluanensis. Although I call this area a ‘proposed’ park, it really is more than that, since the area was identified by the Kluane First Nation in their final land claims settlement as a park. This means it will be a protected area, once all the agreements and plans are in order.”

Interestingly, the story does not end there. Further analysis of specimens collected from Alaska between 2015 and 2017 revealed a second group, ‘unnamed2’, which are genetically distinct from kluanensis, as though they might be a separate species. However, further research into these and other genes shows that these ‘unnamed2’ individuals each have two divergent forms of the COI barcode gene (the section of DNA commonly analysed to uniquely identify a species), a phenomenon that has not yet been widely reported in other bumblebees. For now, because B. kluanensis and ‘unnamed2’ do not show any geographic segregation, they are considered members of the same species, pending further investigation.

Links to further information

Williams, Paul & Berezin, Mikhail & Cannings, Syd & Björn, Cederberg & Ødegaard, Frode & Rasmussen, Claus & Richardson, Leif & Rykken, Jessica & Sheffield, Cory & Thanoosing, Chawatat & Byvaltsev, Alexandr. (2019). (Monograph) The arctic and alpine bumblebees of the subgenus Alpinobombus revised from integrative assessment of species’ gene coalescents and morphology (Hymenoptera, Apidae, Bombus). Zootaxa. 4625. 1-68. 10.11646/zootaxa.4625.1.1.

Natural History Museum species account

Natural History Museum Bombus – Bumblebees of the world homepage

IUCN Bumblebee Specialist Group

Acknowledgements

Many thanks to Syd Cannings for his helpful information.

European Honeybee (Apis mellifera) by Gary Schultz

Our position on managed honeybees

A close up of a honeybee on a pink flower

9 March 2020

The Trust has published a new position statement on managed honeybees. The statement has been prompted by concerns that, under certain circumstances, managed honeybees can have detrimental impacts on wild pollinator species, including bumblebees.

Our Senior Science & Policy Officer, Darryl Cox, provides the background on why we’ve decided to publish the statement.

Q1. What prompted the Trust to produce the position statement?

There is an increasing body of research which shows that, in some situations, beekeeping can have negative consequences for bumblebees (and potentially other pollinators) by increasing competition for food and by passing on diseases. These negative consequences are most marked in areas where there are fewer flowers or higher densities of honeybee hives, and could potentially be serious where vulnerable populations of wild bees are present. This statement aims to mobilise that research into action and highlights important steps that can be taken by beekeepers, conservationists, and anyone else with an interest in helping bumblebees, to lessen any potential negative impacts of managed honeybees.

Q2. Is all beekeeping bad for wild bees?

No. The message is not that beekeeping is bad, and it’s definitely not something we want to avoid or prevent. Our aim with this statement is to help inform people of best practice and encourage responsible beekeeping and well-thought-out hive placement. Keeping honeybees is important economically for honey and wax production, and for pollination of some crops and wild plants, as well as being firmly embedded in our culture. Several of the Trust’s staff and supporters are beekeepers, and are also some of the biggest advocates for wild bee conservation. The important bit is finding the middle ground that balances wild bee conservation and beekeeping, and making sure that rare wild bees aren’t inadvertently harmed.

Q3. What are the main recommendations?

The main recommendation is to take a precautionary approach to how we do beekeeping so that we do not accidentally end up causing problems for our wild pollinator communities. Five specific recommendations are made in the statement which outline how the precautionary principle can be applied in practice.

The position statement is available here. 

Bombus gerstaeckeri by Denis Michez

Bumblebees of the World Blog Series… #9 Bombus gerstaeckeri

A bumblebee, Bombus gerstaeckeri, on a purple flower

by Denis Michez, Researcher at Université de Mons, Belgium.

September’s blog features a vulnerable European bumblebee species, Bombus gerstaeckeri, and comes from Denis Michez, a researcher at Université de Mons, Belgium, who studies global bee diversity and conservation.

Latin name: Bombus gerstaeckeri

Common name/s: None

Colour pattern: Males and females ginger haired thorax that extends on to the top of the abdomen, the rest of which is black with a blonde/white tail (similar to Tree bumblebees, Bombus hypnorum)

Favoured flowers: Aconitums (eg. Monkshoods)

Global region: Palaearctic

Geographic distribution: Europe: Andorra, Austria, France, Germany, Italy, Romania, Russia, Slovenia, Spain, Switzerland, Ukraine

Conservation status: Vulnerable (at European level)

Of all the bumblebees described globally, only three species are described as oligolectic (specialists), which means they have a strong preference for a particular food source. Two species: Bombus consobrinus and B. gerstaeckeri are specialists on plants from the genus Aconitum (Ranunculaceae), which includes Monkshoods, and also B. brodmannicus delmasi, one of the two subspecies belonging to the species B. brodmannicus, shows some degree of oligolectism on the genus Cerinthe (Boraginaceae).

Given their morphological similarity and their food specialisation on Aconitum, it has long been thought that B. consobrinus and B. gerstaeckeri should be two sister species or even two subspecies of the same species. However, the publication of the bumblebee evolutionary history demonstrated that these two species are not sisters. Fascinatingly, the evolutionary event of food specialization on Aconitum plants therefore took place twice, independently. The actual sister species of B. consobrinus and B. gerstaeckeri are B. koreanus  and B. supremus, respectively, two species with Asian distributions, which do not show the same specialisation.

Specialisation on plants with such deep flowers requires an extremely long proboscis (tongue).

Whereas B. consobrinus has a completely palearctic distribution from Norway to Japan, B. gerstaeckeri has a West-Palearctic distribution (Fig. 2) and mainly occurs in fragmented populations across mountainous regions. It is found in the Pyrenees, the Alps, the Carpathians and it is also present in the Caucasus. In the Ukrainian Pyrenees and Carpathians, populations are isolated and made up of a small number of individuals. Four observations in the Romanian Carpathians have also been recorded. When populations exist in isolation like this (Fig. 2), we sometimes find they become genetically distinct from each other over time, but in this case separate populations have remained broadly similar. They were however, more distinct than another more common species, the Garden bumblebee (B. hortorum), which is found across the same areas.

In the Alps and the Pyrenees, B. gerstaeckeri mainly visits the following Aconitum species: Anthora (A. anthora), Monkshood (A. napellus) and Wolf’s bane (A. lycoctonum). Several other food plants are occasionally visited by this species, such as Epilobium angustifolium or Delphinium dubium, probably for the nectar. It is not entirely clear why this specialisation has taken place, however it seems as though B. gerstaeckeri  is reliant on pollen from Aconitum plants for larval development, which could be down to the nutritional content of the pollen, but there is also the possibility that toxins within the plants affect this species’ pollen foraging choice.

Links to further information:

IUCN Redlist page

Natural History Museum species account

Natural History Museum Bombus – Bumblebees of the world homepage

IUCN Bumblebee Specialist Group

 

References

Cameron SA, Hines HM, Williams PH, 2007. A comprehensive phylogeny of the bumble bees (Bombus). Biological Journal of the Linnean Society 91: 161-188.

Dellicour S., Michez D., Mardulyn P. 2015. Comparative phylogeography of five bumblebees: impact of range fragmentation, range size and diet specialisation. Biological Journal of the Linnean Society 116: 926-939.

Delmas R, 1962. Notes zoogéographiques et systématiques sur les Bombidae. I. – Le Bombus brodmannicus Vogt des Alpes françaises. Annales de l’Abeille 5(3): 175-179.

Delmas R, 1976. Contribution à l’étude de la faune française des Bombidae (Hymenoptera, Apoidea, Bombidae). Annales de la Société Entomologique de France (n.s.) 12: 247-290.

Konovalova I, 2007. The first record of the rare oligolectic bumblebee Bombus gerstaeckeri

Morawitz (Hymenoptera: Apidae: Bombini) from Ukraine. Annales de la Société Entomologique de France (n.s.) 43(4): 441-443.

Løken A, 1961. Bombus consobrinus Dahlbom, an oligolectic bumblebee (Hymenoptera, Apidae). Proceeding of the XIth Int. Congr. Ent. 1960 1: 598-603.

Løken A, 1973. Studies on Scandinavian Bumblebees (Hymenoptera, Apidae). Norsk Entomologisk Tidsskrift 20: 1-218.

Mahé G, 2008. Bourdons rares du Parc Naturel Régional du Queyras (Hautes-Alpes, France). OSMIA 2: 21-25.

Moczar M, 1953. Magyarország és a környezö területek dongóméheinek. (Bombus Latr.) rendszere és ökológiája, Magyar Nemzeti Múzeum. Termézettudományi Múzeum évkönyve (Annales Historico-naturales. Musei Nationalis Hungarici). Annales Historico-naturales Musei Nationalis Hungarici 4: 131-159.

Pittioni B, 1937. Bestäubung und Nektarraub beim Gelben Eisenhut (Aconitum vulparia Rchb). Aus der Heimat, Stuttgart 50: 209-213.

Ponchau O, Iserbyt S, Verhaeghe JC, Rasmont P, 2006. Is the caste-ratio of the oligolectic bumblebee Bombus gerstaeckeri Morawitz (Hymenoptera: Apidae) biased to queens? Annales de la Société Entomologique de France 42(2): 207-214.

Tkalců B, 1973. Taxonomie von Pyrobombus brodmannicus (VOGT) (Hymenoptera, Apoidea, Bombinae). Acta entomologica Bohemoslovaca 70 (4): 259-268.

 

Male Bombus brodmannicus by Pierre Rasmont

Bumblebees of the World Blog Series… #10 Bombus brodmannicus

A close up of a male bumblebee, Bombus brodmannicus

by Denis Michez, Researcher at Université de Mons, Belgium and contributor to the IUCN RedList assessment for several European bumblebee species.

This month Bumblebees of the World features Bombus brodmannicus, a poorly understood and endangered bumblebee species found in two fragmented populations separated by more than 2,500km!

Latin name: Bombus brodmannicus

Common name/s: None

Colour pattern: Queens, workers and males have two pale whitish-grey bands on thorax, a broad whitish band at top of abdomen and red tail.

Favoured flowers: Eastern population visits a variety of flowers including clovers. Western sub-species specialises on Cerinthe, although will also visit other plants for nectar, particularly the males.

Global region: Palaearctic

Geographic distribution: Europe, France, Italy, Asia Turkey, Armenia

Conservation status: Endangered (at European level)

In the east B. brodmannicus can be found in north east Turkey and Armenia across the Caucasian mountains, where it can be quite locally abundant. In the West, the subspecies B. brodmannicus delmasi is restricted to high altitudes in the southern French Alps and a small number of nearby locations in Italy. The species is found on southern slopes of the southwestern Alps in subalpine and alpine zones supporting large patches of Cerinthe, its main food plant. The species is active very early in the morning and at sunset.

Last month we talked about how only three species of all bumblebees worldwide are considered as specialists on a particular food plant. Interestingly, the eastern population of B. brodmannicus, located in the Caucasian mountains is a generalist, while the remote subspecies found in certain valleys of the Western Alps (map above), B. brodmannicus delmasi is considered a specialist. This specialism was deduced from field observations reporting a marked preference of the subspecies for Cerinthe minor L. and Cerinthe glabra . Despite the species reliance on pollen from Cerinthe, it is also known to visit other plants such as Calamintha, Cerinthe , Epilobium, Scabiosa, Echium, Nepeta, Knautia and Stachys for nectar. This behavior is particularly relevant for males whose life-cycle is partly offset from the flowering Cerinthe.

The restricted distribution and food specialisation led to an assessment as Endangered in the IUCN Red List of European Bees. Because of its highly specialised foraging requirements and its already localised distribution in a small area of the Alps, the western population seems extremely vulnerable to warming from climate change. On the other hand, the eastern population is rather widespread in the Caucasian region with no apparent food specialisation. It is therefore much less vulnerable to climate change.

Links to further information

IUCN Redlist page

Atlas of European Bumblebees

Natural History Museum species account

Natural History Museum Bombus – Bumblebees of the world homepage

IUCN Bumblebee Specialist Group

References

Dellicour, S., De Jonghe, R., Roelants, D. and Michez, D. 2012. Oligolectisme de Bombus brodmannicus delmasi Tkalců (Hymenoptera, Apidae): observations et analyses. Osmia 5: 8-11.

Delmas, R. 1976. Contribution à l’étude de la faune française des Bombidae (Hymenoptera, Apoidea, Bombidae). Annales de la société entomologique de France (N.S.) 12: 247-290.

Franzén, M. and Molander, M. 2012. How threatened are alpine environments? a cross taxonomic study. Biodiversity Conservation 21: 517-526.

Franzén, M. and Ockinger, E. 2011. Climate-driven changes in pollinator assemblages during the last 60 years in an Arctic mountain region in Northern Scandinavia. Journal of insect conservation 16: 227-238.

Goulson, D., Lye, G.C. and Darvil, B. 2008. Decline and conservation of bumble bees. Annual Review of Entomology 53: 11.1–11.18.

Iserbyt, S. and Rasmont, P. 2012. The effect of climatic variation on abundance and diversity of bumblebees: a ten years survey in a mountain hotspot. Annales de la Société entomologique de France (N.S.) 48(3-4): 261-273.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015.1. Available at: www.iucnredlist.org. (Accessed: 28 May 2015).

Rasmont, P. and Iserbyt, I. 2010-2012. Atlas of the European Bees: genus Bombus. STEP Project. Atlas Hymenoptera. Mons Available at: http://www.zoologie.umh.ac.be//hymenoptera/page.asp?ID=169.

Rasmont, P. and Iserbyt, S. 2012. The Bumblebees Scarcity Syndrome: Are heat waves leading to local extinctions of bumblebees (Hymenoptera: Apidae: Bombus)? Annales de la Société entomologique de France (N.S.) 48(3-4): 275-280.

Tkalcu, B. 1973. Taxonomie von Pyrobombus brodmannicus (Vogt) (Hymenoptera, Apoidea, Bombinae). Acta entomologica bohemoslovaca 70(4): 259-268.

Williams, P.H., Colla, S.R. and Xie, Z. 2009. Bumblebee vulnerability: common correlates of winners and losers across three continents. Conservation Biology 23: 931-940.

Bombus veteranus by John Smit

Bumblebees of the World Blog Series… #11 Bombus veteranus

A bumblebee, Bombus veteranus, feeding on a flower with a large pollen basket

by John Smit, researcher at European Invertebrate Survey – the Netherlands / Naturalis Biodiversity Center, the Netherlands.

This month guest author, John Smit, discusses the conservation of the Sand-coloured carder bee (Bombus veteranus) in the Netherlands, a species which has experienced widespread declines across the country.

Latin name: Bombus veteranus

Common name/s: Sand-coloured Carder bee

Colour pattern: Very constant, all yellowish grey (sandy coloured) with a black thoracic band and thin bands of black hairs on abdominal segments 3-5 in queens and workers and 3-7 in males. Freshly emerged specimen can have bright yellow hairs on the second abdominal segment, especially queens.

Favoured flowers: Red clover, white clover, common comfrey and, to a lesser extent, common bird’s-foot trefoil and water mint. Males can frequently be found on Asteraceae like creeping thistle and goldenrod, but also on sea holly (Apiaceae).

Global region: Entire Palearctic, from western France to the Siberian pacific coast, not present in the Mediterranean part of Europe, nor in England

Geographic distribution: Europe: Austria, Belarus, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Latvia, Lithuania, Luxembourg, the Netherlands, Poland, Romania, Slovak Republic, Sweden, Switzerland, Ukraine. Asia: Russia up to the Pacific coast, including Altai and Sayan mountains and northern Mongolia.

Conservation status: Least Concern

Bombus vetranus is mainly found in the plains of northern Europe, in the southern parts it is confined to slightly higher elevations, with the French Central Massif as the southernmost record. It has disappeared over much of its distribution over the last 100 years, leaving it patchily distributed at present. This is well documented in the Netherlands, where it occurred throughout the country up until the 1970’s, followed by a steep decline. At present it is known from only two areas, along a river and a former estuary.

Evidently, it needs large, open and flower rich areas. The extensive agricultural areas in the Netherlands provided a suitable habitat for this species until agricultural intensification was introduced followed by the use of fertiliser. The borders between the smaller fields and meadows, often consisting of hedgerows, made way for barbed wire and the clover-fields used as a natural fertiliser all but disappeared. There seems to be a strong link between the disuse of red clover as a natural fertiliser and the sharp decline in some of the bumblebee species in the Netherlands. In fact, recent pollen-analyses on Bombus veteranus revealed a strong preference for both red and white clover, as well as common comfrey. Comparison of the pollen load of museum specimens with those of recent specimens revealed a shift in quantity from 64% of both red and white clover together in museum specimens to just 27% in 2017. Conversely common comfrey increased from 24% to 61%, though there are noted differences between the three recent localities surveyed, ranging from 46% at Tiengemeten to 71% at the Biesbosch.

Bombus veteranus is a late appearing species, with queens emerging from hibernation in the end of April or beginning of May and the first workers typically appearing around June, at least in the Netherlands. This is a disadvantage regarding nesting places, compared to the much more common earlier emerging species. It is reported in the literature that nesting typically occurs on the surface, amongst tall grasses or mosses, but can also be underground. The one nest recently found in the Netherlands was situated underground (video below). It consisted of a clump of cells the size of a man’s fist, with no more than 200 to 250 cells. Inside the nest two larvae of the hover fly Volucella bombylans were found, which live as scavengers at the bottom of the nest.

A species action-plan was drawn up for the Netherlands, with measures at the population level. The main goals are to reconnect the two remaining distribution areas and to provide the means for Bombus veteranus to return to the agricultural areas in the Netherlands, where this species can be used as an indicator, or an umbrella species for a more sustainable agricultural system.

Resting bumblebee by Annie Ives

Should you take a bumblebee home?

A bumblebee resting on the ground.

 by Jack Reid, Outreach and Volunteering Officer at Bumblebee Conservation Trust

So, you kidnapped a bumblebee…

Each year, the Trust receives dozens of e-mails and phone calls from well-intentioned beenappers who have been out and about and found a tired-looking lone bumblebee that they’ve rescued and taken home with them to care for. In case you’ve been considering the practicalities of taking a bumblebee home, we have written up this useful guide to caring for your new friend, without taking it home!

Should I take a bumblebee home?

No! Bumblebees have their own homes.

At all times throughout the year, bumblebees have important jobs to be doing – whether it’s queens who are searching for a nest site or gathering pollen for their first clutch of workers; workers who are out, working hard to gather enough pollen and nectar to support their queens and siblings; or males who, despite their work ethic, are vital to ensuring there is a next generation of bumblebees.

For this reason, it’s very important to leave the bumblebees to what they’re supposed to be doing – they can’t support their nests if they can’t get back to them!

What should I feed bumblebees?

Bees need flowers!

Bumblebees are exceptional at identifying the nutrients and foods they need when they are foraging on flowering plants out in the wild. Our knowledge of bumblebee feeding habits is constantly evolving – but nobody knows what they need better than the bumblebees themselves. So we recommend that, rather than taking a tired-looking bumblebee home, you first consider whether they are in danger where they are, or if they’re simply resting!

For more information on if and when to move bumblebees, and when and what to feed them, please click here.

When should I release them?

The best time to leave your bumblebee alone was before you picked them up. The second best time is now!

Bumblebees navigate using landmarks, like buildings, or rocks, or trees. If they can’t find locations that they recognise, they may struggle to find their way back home to their nest when you release them.

If possible, bumblebees should be released near to where you found them. If not, placing them outside on or near to flowering plants is the next best option.

So what do I do if I find a tired bumblebee?

This is a great question – for information on what to do if you find a tired bumblebee, and when to feed, and/or possibly relocate them, please click here.

Bombus eximius by Chawatat Thanoosing

Bumblebees of the World Blog Series… #8 Bombus eximius

The Orange-legged bumblebee, Bombus-eximius

By Chawatat Thanoosing, PhD student and Paul Williams, researcher at the Natural History Museum London

This month we’ll explore a deep montane tropical forest in Asia, where Chawatat Thanoosing— a PhD student at Imperial College London and the Natural History Museum—is doing his research on the ecology of tropical bumblebees, to see the remarkable giant bumblebee, Bombus eximius.

Latin name: Bombus eximius

Common name/s: Orange-legged bumblebee

Colour pattern: Whole body mainly black with brightly orange tail and legs in all castes.

Favoured flowers: Mid altitude flowering shrubs and trees, and wild orchids

Global region: Oriental region

Geographic distribution: Asia: India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Vietnam, China, and Taiwan

Conservation status: Not evaluated

The impressive Bombus eximius is a broadly distributed Asian bumblebee, found across the Himalayas, Southern China, Taiwan island and in the mountain ranges of northern Southeast Asia, at mid altitude, from approximately 1000 m above sea level. Unlike common bumblebees in Europe (eg. B. terrestris), which show black and yellow striped patterns on their abdomen, B. eximius is often a predominantly black bumblebee with orange on their tail and legs, although sometimes the populations in Southern China and Taiwan have extensively orange abdomens as well.. This orange-colouring across the legs is in congruence with the original subgeneric group that this species was attributed to, Rufipedibombus, which means red-legged bumblebees, although it is now included as part of Melanobombus, distantly related to the European B. lapidarius.

Queens of B. eximius are some of the largest bumblebees in the world. The body length of the queen is approximately 3 cm long, similar in size to the Patagonian bumblebee, B. dahlbomii, in South America. Strangely, those big bumblebees show almost the opposite colour pattern between them. They have an orange thorax and abdomen with black legs, whereas B. eximius often has a a black body and orange legs. The two species have evolved independently in different lineages and different geographic regions.

The food preference of B. eximius has rarely been studied. In Thailand, this species has been reported visiting and pollinating some native orchids: Dendrobium infundibulum and Cymbidium insigne. Care is needed when identifying these bees because B. eximius is mimicked very closely by B. flavescens, a relative of B. pratorum. When B. eximius lands on an orchid flower, pollinia (a sticky orchid pollen mass) will either attach to its thorax (in D. infundibulum flowers) or abdomen (in C. insigne flowers). The cross-pollination of the orchids occurs when the bumblebee with attached pollinia visits another orchid flower. In addition, at Doi Inthanon mountain, the highest peak in northern Thailand, B. eximius has been observed to visit Hooker’s St. John’s Worts (Hypericum hookerianum), Som Pae (local Thai name for Vaccinium exaristatum), Rubus chevalieri and Saurauia napaulensis for food.

The IUCN conservation status of this bumblebee has not yet been assessed. This species still flies and hides in the shady forests of the mountains. Despite extreme deforestation, land use changes and heavy pesticide use in this region, no one knows whether the population of this bumblebee is decreasing or not. From the obvious changes in the environment, raising awareness and protecting bumblebees in this region are likely to be urgently needed.

Links to further information:

Natural History Museum species account

Natural History Museum Bombus – Bumblebees of the world homepage

Williams, P. H., Ito, M., Matsumura, T., & Kudo, I. (2010) The bumblebees of the Nepal Himalaya (Hymenoptera: Apidae). Insecta Matsumurana. 66, 115­–151

Williams, P. H., Tang, Y., Yao, J., & Cameron, S. (2009) The bumblebees of Sichuan (Hymenoptera: Apidae, Bombini). Systematics and Biodiversity. 7, 101–190

Kjellsson, G., Rasmussen, F. N. & Dupuy, D. (1985) Pollination of Dendrobium infundibulum, Cymbidium insigne (Orchidaceae) and Rhododendron lyi (Ericaceae) by Bombus eximius (Apidae) in Thailand: A Possible Case of Floral Mimicry. Journal of Tropical Ecology. 1, 289–302