Clever Bees Can Identify Different Flowers by Patterns of Scent

June 14, 2018


Certain aromas trigger memories in humans, transporting us back in time. But how well do bees understand scent? And can they translate scent cues into a visual imprint? New research led by scientists from the University of Bristol and Queen Mary University of London demonstrates that bumble bees have keen sniffers, letting them tell flowers apart by patterns of scent.

Flowers have lots of different patterns on their surfaces that help to guide bees and other pollinators towards the flower's nectar, speeding up pollination. These patterns include visual signals like lines pointing to the center of the flower, or color differences. Flowers are also known to have different patterns of scent across their surface, and so a visiting bee might find that the centre of the flower smells differently to the edge of the petals.

Bumble bees can tell flowers apart simply by how scent is arranged on their surface according to new research published in the Proceedings of the Royal Society B. Lead author Dr. Dave Lawson, from the University of Bristol's School of Biological Sciences, said: "If you look at a flower with a microscope, you can often see that the cells that produce the flower's scent are arranged in patterns.

"By creating artificial flowers that have identical scents arranged in different patterns, we are able to show that this patterning might be a signal to a bee. For a flower, it's not just smelling nice that's important, but also where you put the scent in the first place."

The study also shows that once bees had learnt how a pattern of scent was arranged on a flower, they then preferred to visit unscented flowers that had a similar arrangement of visual spots on their surface.

Dr. Lawson added: "This is the equivalent of a human putting her hand in a bag to feel the shape of a novel object which she can't see, and then picking out a picture of that object. Being able to mentally switch between different senses is something we take for granted, but it's exciting that a small animal like a bee is also able to do something this abstract."

Professor Lars Chittka, from Queen Mary's School of Biological and Chemical Sciences, said: "We already knew that bees were clever, but we were really surprised by the fact that bees could learn invisible patterns on flowers - patterns that were just made of scent.

"The scent glands on our flowers were either arranged in a circle or a cross, and bees had to figure out these patterns by using their feelers. But the most exciting finding was that, if these patterns are suddenly made visible by the experimenter, bees can instantly recognize the image that formerly was just an ephemeral pattern of volatiles in the air."

Senior author, Dr. Sean Rands, also from Bristol, added: "Flowers often advertise to their pollinators in lots of different ways at once, using a mixture of color, shape, texture, and enticing smells.

"If bees can learn patterns using one sense (smell) and then transfer this to a different sense (vision), it makes sense that flowers advertise in lots of ways at the same time, as learning one signal will mean that the bee is primed to respond positively to different signals that they have never encountered.

"Advertising agencies would be very excited if the same thing happened in humans."

Around 75 percent of all food grown globally relies on flowers being pollinated by animals such as bees. The work published today is part of ongoing research at the University of Bristol that explores the many different ways in which plants communicate with their pollinators, using different innovative techniques to explore how bees perceive the flowers that they visit.

Service Proposes Protections for Rusty Patched Bumble Bee Under Endangered Species Act

U.S. Fish and Wilslife Service - News Release   September 21, 2016

Rusty patched bumble bee. Photo courtesy of Dan Mullen/Creative Commons.The U.S. Fish and Wildlife Service will propose the rusty patched bumble bee as endangered under the Endangered Species Act, citing a steep decline in the species’ numbers throughout its range. The rusty patched bumble bee, once widespread, is now found in scattered, small populations in 12 states and one Canadian province.

Twenty years ago, the rusty patched bumble bee was an abundant native pollinator found across a broad geographic range that included 28 states and the District of Columbia, from Connecticut to South Dakota and north into two provinces in Canada. The rusty patched bumble bee is now found only in Illinois, Indiana, Maine, Maryland, Massachusetts, Minnesota, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, Wisconsin – and Ontario, Canada. Abundance and distribution of rusty patched bumble bee populations have declined by an estimated 91 percent since the mid to late 1990s.

Threats to the rusty patched bumble bee include disease (for example, from infected commercial honeybee colonies), exposure to pesticides, habitat loss, the effects of climate change, the effects of extremely small populations, and a combination of these factors.

Bumble bees such as the rusty patched are important pollinators of plants and wildflowers that provide food and habitat for other wildlife. They are also the chief pollinator of many economically important crops. Bumble bees are able to fly in cooler temperatures and lower light levels than many other bees, such as honey bees, making them excellent pollinators for crops like tomatoes, peppers and cranberries. Even where crops can be self-pollinated, the plant produces more and bigger fruits when pollinated by bumble bees.

The ESA helps focus resources, attention and collaborations on behalf of imperiled species and inspires proactive conservation efforts. The Service has been actively working with partners to prevent the extinction of pollinators by locating, protecting and restoring existing habitat.  Long-term strategies for the rusty patched bumble bee may also include captive rearing and research.

There are also timely actions that citizens, communities and landowners can take to conserve and restore rusty patched bumble bees. For populations located in urban areas, citizens can plant native flowers that bloom throughout the growing season and leave flowers on the stem as long as possible, especially in fall. This provides bees with needed resources for making it through the winter and for producing new colonies in the spring. For populations on or near agricultural lands, landowners can refrain from haying in early fall and follow best management practices for pesticide use.

The Service’s proposal to list the rusty patched bumble bee is published in the September 22, 2016, Federal Register. Comments on the proposal are accepted through November 21, 2016. Following the close of the comment period, the Service will evaluate any new information and make a determination on whether to list the species.

You may submit comments by one of the following methods:

  • Electronically: Go to the federal eRulemaking Portal at In the Search box, enter FWS–R3–ES–2015–0112, which is the docket number for this rulemaking. Then, in the Search panel on the left side of the screen, under the Document Type heading, click on the Proposed Rules link to locate this document. You may submit a comment by clicking on “Comment Now!”
  •  Submit hard copies by U.S. mail or hand-delivery to: 

    Public Comments Processing 
    Attn: FWS–R3–ES–2015–0112
    U.S. Fish & Wildlife Headquarters, MS: BPHC
    5275 Leesburg Pike
    Falls Church, VA 22041-3803

We will accept and consider comments and information we receive or postmarked on or before November 21, 2016. We must receive comments submitted electronically using the federal eRulemaking Portal by 11:59 p.m. Eastern Time on the closing date.

To see the Service’s proposal to list the rusty patched bumble bee and learn more about the species go to

Primitive Signs of Emotions Spotted in Sugar-Buzzed Bumblebees

science Daily     By Emily Underwood     September 30, 2016

After a treat, insects appeared to have rosier outlooks

BUZZED Bumblebees seem to get a mood boost from sweets, a new study shows.

To human observers, bumblebees sipping nectar from flowers appear cheerful. It turns out that the insects may actually enjoy their work. A new study suggests that bees experience a “happy” buzz after receiving a sugary snack, although it’s probably not the same joy that humans experience chomping on a candy bar.

Scientists can’t ask bees or other animals how they feel. Instead, researchers must look for signs of positive or negative emotions in an animal’s decision making or behavior, says Clint Perry, a neuroethologist at Queen Mary University of London. In one such study, for example, scientists shook bees vigorously in a machine for 60 seconds — hard enough to annoy, but not hard enough to cause injury — and found that stressed bees made more pessimistic decisions while foraging for food.

The new study, published in the Sept. 30 Science, is the first to look for signs of positive bias in bee decision making, Perry says. His team trained 35 bees to navigate a small arena connected to a plastic tunnel. When the tunnel was marked with a blue flower, the bees learned that a tasty vial of sugar water awaited them at its end. When a green flower was present, there was no reward. Once the bees learned the difference, the scientists threw the bees a curveball: Rather than being blue or green, the flower had a confusing blue-green hue.

Faced with the ambiguous blossom, the bees appeared to dither, meandering around for roughly 100 seconds before deciding whether to enter the tunnel. Some didn’t enter at all. But when the scientists gave half the bees a treat — a drop of concentrated sugar water — that group spent just 50 seconds circling the entrance before deciding to check it out. Overall, the two groups flew roughly the same distances at the same speeds, suggesting that the group that had gotten a treat first had not simply experienced a boost in energy from the sugar, but were in a more positive, optimistic state, Perry says.

In a separate experiment, Perry and colleagues simulated a spider attack on the bees by engineering a tiny arm that darted out and immobilized them with a sponge. Sugar-free bees took about 50 seconds longer than treated bees to resume foraging after the harrowing encounter.

The researchers then applied a solution to the bees’ thoraxes that blocked the action of dopamine, one of several chemicals that transmit rewarding signals in the insect brain. With dopamine blocked, the effects of the sugar treat disappeared, further suggesting that a change in mood, and not just increased energy, was responsible for the bees’ behavior.

The results provide the first evidence for positive, emotion-like states in bees, says Ralph Adolphs, a neuroscientist at Caltech. Yet he suspects that the metabolic effects of sugar did influence the bees’ behavior.

Geraldine Wright, a neuroethologist at Newcastle University in England, shares that concern. “The data reported in the paper doesn’t quite convince me that eating sucrose didn’t change how they behaved, even though they say it didn’t affect flight time or speed of flight,” she says. “I would be very cautious in interpreting the responses of bees in this assay as a positive emotional state.”

Bumblebee Skilled at "buzz pollination" May Soon Join the Endangered Species

The Los Angeles Times    By Jessica Roy   September 22, 2016

A rusty patched bumblebee collects pollen from a flower. The U.S. Fish and Wildlife Service has formally recommended the bee species for endangered status. (Rich Hatfield/Xerces Society)A type of bumblebee native to North America may soon be named to the endangered species list. It would be the first bee species to be considered endangered in the United States.

The U.S. Fish and Wildlife Service on Thursday formally proposed that the Bombus affinis, or rusty patched bumblebee, be listed as endangered under the guidelines of the Endangered Species Act.

"As pollinators, rusty patched bumblebees contribute to our food security and the healthy functioning of our ecosystems," the Fish and Wildlife Service said in a statement. The federal agency estimates that native insect species, particularly bees, contribute $3 billion in economic value annually in the United States. Because of a specialized pollen-shedding movement called "buzz pollination," bumblebee species are better at pollinating some crops than honeybees.

The Xerces Society for Invertebrate Conservation filed a formal petition in 2013 seeking to place the rusty patched bumblebee on the endangered list. According to the conservation organization, the species' population has declined 87% in recent years.

Another Xerces Society petition on has garnered more than 128,000 signatures this year alone.

Rusty patched bumblebees contribute to our food security and the healthy functioning of our ecosystems.— U.S. Fish and Wildlife Service

The bees’ decline can be attributed to habitat loss, climate changedisease, farming andpesticides, according to the Fish and Wildlife Service.

The rusty patched bumblebee — so named for a distinctive colored patch on the abdomens of worker bees — is particularly apt at pollinating cranberries, plums, alfalfa, onion seed and apples. Its life cycle begins earlier in spring and extends later into the fall than most other types of bumblebees.

The species used to be found across at least 26 states in the Midwest and Northeast; in recent years, sightings have shrunk to just a few states, the Xerces Society reported.

Per the rules of the Endangered Species Act, the next step is a 60-day period in which members of the public, scientists and government agencies can submit expert opinions and other input. Comments may be submitted online until Nov. 21. 

After that, the Fish and Wildlife Service will announce its decision.

Small Farms Benefit Significantly From a Few Extra Pollinators

  January 21, 2016

American Association for the Advancement of Science

A white-tailed bumblebee (Bombus lucorum) pollinating a sunflower (Helianthus sp.).

This material relates to a paper that will appear in the 22 January 2016, issue of Science, published by AAAS. The paper, by Lucas Alejandro Garibaldi at Instituto de Investigaciones en Recursos Naturales, Agroecología y Desarrollo Rural (IRNAD) in Río Negro, Argentina, and colleagues was titled, "Mutually beneficial pollinator diversity and crop yield outcomes in small and large farms." Credit: Arnstein Staverløkk

Higher numbers of pollinators can significantly increase crop productivity of small-sized farms, while large farms experience a similar yield benefit only if increases in pollinator density are accompanied by diversity, a new study finds. More than two billion people are reliant on small-scale agriculture in developing nations, and while much evidence demonstrates that pollinators can beneficially affect crop yield, how these helpful critters affect small-scale farms compared to larger farms is mostly unknown. To gain more insights, Lucas Garibaldi et al. analyzed 344 fields of small and large holdings in Africa, Asia, and Latin America, recording the number of pollinators (density), their biodiversity, and the yield of each crop over a five-year period. For small holdings less than two hectares, their analysis found that yield gaps -- the difference between crops that yielded the most produce compared to those that yielded the least -- could be closed by 24% through higher pollinator density; the authors note that the remaining 76% of the yield gap may be partially closed by technologies that optimize other agricultural factors, such as nutrients and water. In contrast, for larger holdings, a similar yield benefit from pollinator density only occurred if accompanied by high pollinator diversity. The authors suggest that large crops may benefit less from pollinator density because these are more likely to be pollinated by flower visitors with longer foraging ranges, which are usually generalist species, such as honey bees. Although pollinator dynamics are being increasingly threatened in agroecosystems because of declining floral abundance and diversity, the authors note that there are opportunities to reverse the trend by a number of different means, including planting flower strips, more targeted use of pesticides, and restoring natural areas adjacent to crops.

Inside the Wonderful World of Bee Cognition

American Scientific    By Felicity Muth  April 20, 2015

A bumblebee drinks sugar water from an artificial flower and learns to return to yellow flowers in the future. Credit: Caroline StrangAs I wrote about in my last post, bees are capable of learning which flowers offer good nectar rewards based on floral features such as colour, smell, shape, texture, pattern, temperature and electric charge. They do this through associative learning: learning that a ‘conditioned stimulus’ (for example, the colour yellow) is associated with an ‘unconditioned stimulus’ (nectar). Learning simple associations like these is the basis of all learning – pretty much all animals do it, from humans to the sea slug which doesn’t even have a brain.

However, the world is rarely as simple as this and so animals need to be flexible. For example, as humans we might learn that if we put our bank card in a machine and enter a pin number we can obtain money. However, we might also have to learn that we can only access the bank machine inside the bank during particular hours, or that if we travel to another country their bank machines might operate differently. Therefore we need some behavioural flexibility around what we’ve learned. The same is true for bees. In a bee’s world, much of what she learns relates to getting food from flowers. However, it won’t always be as simple as ‘blue flowers have better nectar than yellow rewards’. Instead a bee might have to learn ‘blue flowers have better nectar than yellow flowers, but only in the morning’ or ‘this particular species of blue flower which also has a specific smell has better nectar than yellow flowers, but another species of blue flower has worse nectar’.

Honeybees can learn that two separate stimuli (i.e. yellow checkers and blue checkers) are good but that the combination isn't good

Honeybees can indeed learn more complex relationships like this. This has been shown in many different experiments using different protocols and in different contexts. For example, bees can be trained that an artificial flower which has a blue checkered pattern has good nectar rewards, and one with a yellow checkered pattern has good nectar rewards but a combination of the two (blue and yellow checkered) is not good. They can also be trained to the reverse (that the combination of the two stimuli is good, but that either by themselves is not good). Similarly, honeybees can be trained that only very particular combinations of stimuli are good; i.e. A and B together are good, and C and D together are good, but any other combination (e.g. A and C or B and D) are not good. The list of other complex relationships bees can learn is seemingly endless, but other impressive feats include honeybees’ ability to learn that rewards can be found in a specific location only at one particular time of day and that bumblebees can learn that the location of nectar alternates between two available options and solve physical problems

However, honeybees’ and bumblebees’ cognitive abilities go beyond these examples of simply learning about their worlds, be it under a number of complex conditions. One excellent study showed that bees could actually form abstract concepts about their world. Having an abstract concept is the ability to understand a general fact about the way things are and to being able to generalise that fact to new situations you might encounter, as opposed to learning relationships that only hold in one particular situation. As humans, we form abstract concepts about the world all the time, generalising from one situation to another. For example, one concept we form about the world is the concept of ‘sameness’ and ‘difference’. If we were having dinner together and I asked you if you’d like ‘more of the same’, you would understand that if we had just been eating pasta that I was offering you more pasta. In another, totally different situation, say we’re operating on someone together and I ask you to pass me ‘the same instrument for stitching people closed that you just gave me a minute ago’ (I’m not sure why any doctor would ever phrase it this way; but let’s just suppose that they don’t have a great memory for medical instrument names), you would understand that you needed to pass me another needle. Therefore, you have the ability to take the concept of ‘sameness’ and use it in two totally different situations. But how would you go about asking a bee if she can do the same thing?

How do you test for abstract concepts in bees?

Researchers did this through a cleverly thought-out experiment. First they trained a bee that if she saw a particular colour (say, blue) then when she was later given a choice between blue and yellow, blue always had nectar whereas yellow did not (stages 1 and 2 on the diagram). Similarly, she was trained that if she saw yellow then when she was later given a choice, she had to choose yellow to get the reward (steps 3 and 4 on the diagram). Therefore, she always had to go to the same colour as the one she had previously seen to get the reward. The bees learned this without much difficulty. However, at this point it’s not clear whether the bee had actually learned the concept of ‘sameness’ or instead had just learned a rule for this one situation (e.g. ‘I go to yellow to get a reward when I see yellow and I go to blue to get a reward when I see blue’). To test whether the bees had actually learned the concept of ‘same’, the researchers then presented the bee with a new stimulus, one she had never seen before. This time it was a pattern: black and white horizontal stripes. The bee was then given a ‘transfer test’; a choice between a black and white striped horizontal pattern or a vertical pattern. If the bee had learned the rule ‘when I see a stimulus I then need to choose the same stimulus to get a reward’ (i.e. the concept of ‘same’) then she should fly to the horizontal stripes pattern (steps 5 and 6 on the diagram). This is indeed what the majority of bees did. Another group of bees were trained only to black and white horizontal patterns and then given transfer tests using blue and yellow colours; these bees also showed that they had learned the concept of ‘same’ by going to the correct colour. Now, the really cool part of this experiment was that the researchers then gave a new set of bees stimuli in a totally different modality: scent. Bees were trained that when they smelled a particular odour, they had to go to the same odour to get a reward. They were then given a transfer test in colour, and the bees transferred their knowledge to this new context, going to the ‘correct’ colour even though they had never been trained with colour before. In another set of bees, individuals were trained to go to the different stimulus to the one they had just seen before being given a transfer test, and their choices showed that they were also able to learn the concept of ‘difference’.

Bumblebee on flower. Credit: jinterwasAfter I tell people about some of these impressive cognitive abilities that bees have, another question that I often get asked is, ‘OK, so if bees are so smart, then why do they always fly into windows?’. I hope from what you’ve read in these two posts you can appreciate that when you want to ask a question of a bee you have to frame it in a way that the bee ‘understands’. If we were to ask a human a question, we could use language, to ask a bee a question, you generally use stimuli that represent flowers and nectar. Like all animals, the cognitive abilities of bees have been selected by natural selection to make the bee as good as possible at learning about things that it needs to know about its environment. This includes many complex relationships about how to get the best food from flowers, but sadly, doesn’t include the ability of how to best navigate windows.

Read at:


Clarke, Dominic, Heather Whitney, Gregory Sutton, and Daniel Robert. 2013. “Detection and Learning of Floral Electric Fields by Bumblebees.” Science (New York, N.Y.) 340(6128): 66–69.
Dyer, Adrian G et al. 2006. “Behavioural Ecology: Bees Associate Warmth with Floral Colour.” Nature 442(7102): 525.
Von Frisch, K. 1956. Bees; their vision, chemical senses, and language. Ithaca, N.Y., Cornell University Press.
Von Frisch, K. 1967. The Dance Language and Orientation of Bees. Cambridge, Massachusetts: Harvard University Press.
Giurfa, M., Zhang, S., Jenett, A., Menzel, R., & Srinivasan, M. V. (2001). The concepts of ‘sameness’ and ‘difference’ in an insect. Nature410(6831), 930-933.
Pahl, M., Zhu, H., Pix, W., Tautz, J., & Zhang, S. (2007). Circadian timed episodic-like memory–a bee knows what to do when, and also where. The Journal of experimental biology210(20), 3559-3567.
Schubert, Marco, Harald Lachnit, Silvia Francucci, and Martin Giurfa. 2002. “Nonelemental Visual Learning in Honeybees.” Animal Behaviour 64(2): 175–84.
Strang, C. G., & Sherry, D. F. (2014). Serial reversal learning in bumblebees (Bombus impatiens). Animal cognition, 17(3), 723-734.

Bumble Bees and Spiders Don't Mix?

Bug Squad - Happenings in the Insect World   By Kathy Keatley Garvey

Bumble bees and spiders don't mix, you say?

Well, they will at the Bohart Museum of Entomology's open house from 1 to 4 p.m., Saturday, July 26. The family-centered event, free and open to the public, takes place in Room 1124 of the Academic Surge building on Crocker Lane, UC Davis campus.

Actually the theme is about spiders: "Arachnids: Awesome or Awful?" There you'll see black widow spiders, jumping spiders, cellar spiders and the like. But you don't have to "like" them as...


Bee Foraging Chronically Impaired by Pesticide Exposure: Study

The following is brought to us by the American Bee Journal     July 10, 2014

A study co-authored by a University of Guelph scientist that involved fitting bumblebees with tiny radio frequency tags shows long-term exposure to a neonicotinoid pesticide hampers bees' ability to forage for pollen.

The research by Nigel Raine, a professor in Guelph's School of Environmental Sciences, and Richard Gill of Imperial College London was published July 9 in the British Ecological Society's journal Functional Ecology.

The study shows how long-term pesticide exposure affects individual bees' day-to-day behavior, including pollen collection and which flowers worker bees chose to visit.

"Bees have to learn many things about their environment, including how to collect pollen from flowers," said Raine, who holds the Rebanks Family Chair in Pollinator Conservation, a Canadian first.

"Exposure to this neonicotinoid pesticide seems to prevent bees from being able to learn these essential skills."

The researchers monitored bee activity using radio frequency identification (RFID) tags similar to those used by courier firms to track parcels. They tracked when individual bees left and returned to the colony, how much pollen they collected and from which flowers.

Bees from untreated colonies got better at collecting pollen as they learned to forage. But bees exposed to neonicotinoid insecticides became less successful over time at collecting pollen.

Neonicotinoid-treated colonies even sent out more foragers to try to compensate for lack of pollen from individual bees.

Besides collecting less pollen, said Raine, "the flower preferences of neonicotinoid-exposed bees were different to those of foraging bees from untreated colonies."

Raine and Gill studied the effects of two pesticides – imidacloprid, one of three neonicotinoid pesticides currently banned for use on crops attractive to bees by the European Commission, and pyrethroid (lambda cyhalothrin) – used alone or together, on the behavior of individual bumblebees from 40 colonies over four weeks.

"Although pesticide exposure has been implicated as a possible cause for bee decline, until now we had limited understanding of the risk these chemicals pose, especially how it affects natural foraging behavior," Raine said.

Neonicotinoids make up about 30 per cent of the global pesticide market. Plants grown from neonicotinoid-treated seed have the pesticide in all their tissues, including the nectar and pollen.

"If pesticides are affecting the normal behavior of individual bees, this could have serious knock-on consequences for the growth and survival of colonies," explained Raine.

The researchers suggest reform of pesticide regulations, including adding bumblebees and solitary bees to risk assessments that currently cover only honeybees.

"Bumblebees may be much more sensitive to pesticide impacts as their colonies contain a few hundred workers at most, compared to tens of thousands in a honeybee colony," Raine said.

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The Buzz About Bumblebees: National Wildlife Federation

The Buzz at OSU   By Denise Ellsworth   4/15/14

Across North America and beyond, bumblebees are in trouble, but gardeners can help these critical pollinators. 

TO BIOLOGIST SAM DROEGE, they are “the teddy bears of the bee world.” Fat, fuzzy and occasionally clumsy fliers, “bumblebees are cute,” says Droege, who heads the U.S. Geological Survey’s Bee Inventory and Monitoring Lab. “People project emotions on them”—an assertion backed by the many children’s books and songs featuring bumblebees.

All members of the genus Bombus, the world’s roughly 250 bumblebee species are critical pollinators. In natural ecosystems, bees are by far the most important pollinators of native plants, and the insects are essential to producing more than a third of the foods and beverages humans consume—an industry worth hundreds of billions of dollars annually. Bumblebees are particularly major players: Because their large bodies allow them to generate heat, the insects can fly earlier and later in the day and in colder weather than most bee species, including honeybees.

Bumblebees are also strong flyers. Powered by contractions of the thorax, or midsection, the insects’ wings beat 130 or more times per second. That prowess, combined with their size, allows bumblebees to perform a unique service, “buzz pollination” (vibrating flowers until they release pollen), that helps plants produce more fruit. And bumblebees’ significance as pollinators has been growing in recent years as managed colonies of European honeybees decline.

But it turns out that bumblebees are in trouble, too. In North America, four once-common, widespread Bombus species have vanishedfrom large portions of their former ranges. A fifth may already be extinct...


Bye Bye Bumblebees

Global Possibilities    4/2/14

A Quarter of Europe's Bumblebees, Vital to Agriculture, Face Extinction 

OSLO, April 2 (Reuters) – Almost a quarter of Europe’s bumblebees are at risk of extinction due to loss of habitats and climate change, threatening pollination of crops worth billions of dollars, a study showed on Wednesday.

Sixteen of 68 bumblebee species in Europe are at risk, the Red List of the International Union for Conservation of Nature (IUCN) said. It is preparing a global study of the bees, whose honeybee cousins are in steep decline because of disease.

“Of the five most important insect pollinators of European crops, three are bumblebee species,” said the IUCN, which groups governments, scientists and conservation groups.

“Together with other pollinators, bumblebees contribute more than 22 billion euros ($30.35 billion) to European agriculture a year,” it said in a statement.

Of Europe’s bumblebee species, populations of almost half are falling and just 13 percent are increasing, it said.

Often with yellow and black stripes and bigger than honeybees, bumblebees live in small nests of up to 200 and do not make honeycombs. Some bumblebees are commercially bred to pollinate tomatoes, peppers and aubergines in greenhouses.

“Climate change, the intensification of agriculture and changes in agricultural land are the main threats” to bumblebees, said the report, the first Red List assessment of threats to bumblebees.

The European Union’s top environment official said the 28-nation bloc was taking action to improve the situation.

“The EU recently banned or restricted the use of certain pesticides that are dangerous to bees and is funding research into status of pollinators,” said EU Environment Commissioner Janez Potonik in a statement.

“However, efforts clearly need to be scaled up,” he added. The IUCN study was funded by the European Commission.


The study did not mention the possibility that honeybee diseases were spreading to bumblebees.

A study in the journal Nature in February said that deformed wing virus, for instance, was found in both honeybees and bumblebees in Britain. The virus was more prevalent in honeybees, suggesting it was spreading from them to bumblebees.

“In general, we don’t know a lot about bumblebee disease,” Stuart Roberts, a member of the IUCN’s global bumblebee assessment team, told Reuters.

“Some of these threatened bumblebees are isolated, living in the Arctic or the Alps,” he said. “In those places the chance of picking up a disease from a honeybee is almost nil.”

The Arctic species Bombus hyperboreus, living in the Scandinavian tundra and Russia, is vulnerable because global warming is shrinking its habitat, the study said.

Populations of the critically endangered Bombus cullumanus, now found only in France, have fallen by more than 80 percent in the past decade, apparently because of a reduction in the amount of meadows with clover, its favourite forage, the study added.

Only queen bumblebees survive the winter.

Honeybees, living in longer-lasting colonies of thousands of bees, make honeycombs largely to ensure that the insects have food to survive months with no nectar-making flowers. ($1 = 0.7249 Euros) (Editing by Gareth Jones)

Bees Capable of Learning Feats with Tasty Prize in Sight

  Science Daily     Source: University of Guelph  3/18/14 

Bumblebees are capable of some remarkable learning feats, especially when they might get a tasty reward, according to two studies. In the first study, the researchers found bees capable of learning to solve increasingly complex problems, an example of scaffold learning. In a second study, the researchers found bees learned by watching and communicating with other bees, a process called social learning.

They may have tiny brains, but bumblebees are capable of some remarkable learning feats, especially when they might get a tasty reward, according to two studies by University of Guelph researchers.

PhD student Hamida Mirwan and Prof. Peter Kevan, School of Environmental Sciences, are studying bees' ability to learn by themselves and from each other.

In the first study, published in February in Animal Cognition, the researchers found bees capable of learning to solve increasingly complex problems.

The researchers presented bees with a series of artificial flowers that required ever-more challenging strategies, such as moving objects aside or upwards, to gain a sugar syrup reward.

When inexperienced bees encountered the most complex flower first, they were unable to access the syrup reward and stopped trying. Bees allowed to progress through increasingly complex flowers were able to navigate the most difficult ones.

"Bees with experience are able to solve new problems that they encounter, while bees with no experience just give up," said Mirwan.

She and Kevan consider the study an example of scaffold learning, a concept normally restricted to human psychology in which learners move through increasingly complex steps.

In a second study recently published in Psyche,the researchers found bees learned by watching and communicating with other bees, a process called social learning.

Mirwan made artificial flowers requiring the bees to walk on the underside of a disk to get a sugar syrup reward. These experienced bees foraged on the artificial flowers for several days until they became accustomed to feeding at them.

To see whether other bees could learn from the experienced foragers, Mirwan confined inexperienced bees in a mesh container near the artificial flowers where they could observe the experienced bees. When the naïve bees were allowed to forage on the artificial flowers, they took just 70 seconds to get the reward.

Control bees that had not observed the experienced bees could not access the syrup.

"Social learning in animals usually involves one individual observing and imitating another, although other kinds of communication can also be involved," said Mirwan.

"They could try for up to 30 minutes, but most gave up before then."

In a final test, Mirwan placed experienced bees in a hive with naive bees. When the naive bees were allowed to forage on the artificial flowers, they gained the syrup in just 3.5 minutes.

Behavioural scientists usually assume that observation and imitation are at the heart of social learning, but social insects such as bees can also transmit information through touch, vibration and smell.

The researchers said the communication method used by the bees is still a mystery.

"We can't quite explain how bees that had never even seen an artificial flower were able to become adept so quickly at foraging on them, but clearly some in-hive communication took place," said Kevan.

"It suggests that social learning in bumblebees is even more complex than we first expected."


Bumblebees Getting Stung Bad By Honeybee Sickness   By Seth Borenstein    2/19/14   

WASHINGTON (AP) - Wild bumblebees worldwide are in trouble, likely contracting deadly diseases from their commercialized honeybee cousins, a new study shows.

That's a problem even though bumblebees aren't trucked from farm to farm like honeybees. They provide a significant chunk of the world's pollination of flowers and food, especially greenhouse tomatoes, insect experts said. And the ailments are hurting bumblebees even more, according to a study published Wednesday in the journal Nature.

"Wild populations of bumblebees appear to be in significant decline across Europe, North America, South America and also in Asia," said study author Mark Brown of the University of London. He said his study confirmed that a major source of the decline was "the spillover of parasites and pathogens and disease" from managed honeybee hives.

Smaller studies have shown disease going back and forth between the two kinds of bees. Brown said his is the first to look at the problem in a larger country-wide scale and include three diseases and parasites. The study tracked nearly 750 bees in 26 sites throughout Great Britain. And it also did lab work on captive bees to show disease spread...


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Disease Associations Between Honeybees and Bumblebees as a Threat to Wild Pollinators  M. A. FürstD. P. McMahonJ. L. OsborneR. J. Paxton M. J. F. Brown  2/20/14

Emerging infectious diseases (EIDs) pose a risk to human welfare, both directly1 and indirectly, by affecting managed livestock and wildlife that provide valuable resources and ecosystem services, such as the pollination of crops2. Honeybees (Apis mellifera), the prevailing managed insect crop pollinator, suffer from a range of emerging and exotic high-impact pathogens34, and population maintenance requires active management by beekeepers to control them. Wild pollinators such as bumblebees (Bombus spp.) are in global decline56, one cause of which may be pathogen spillover from managed pollinators like honeybees78 or commercial colonies of bumblebees9. Here we use a combination of infection experiments and landscape-scale field data to show that honeybee EIDs are indeed widespread infectious agents within the pollinator assemblage. The prevalence of deformed wing virus (DWV) and the exotic parasite Nosema ceranae in honeybees and bumblebees is linked; as honeybees have higher DWV prevalence, and sympatric bumblebees and honeybees are infected by the same DWV strains, Apis is the likely source of at least one major EID in wild pollinators. Lessons learned from vertebrates1011 highlight the need for increased pathogen control in managed bee species to maintain wild pollinators, as declines in native pollinators may be caused by interspecies pathogen transmission originating from managed pollinators.

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Pesticides 'Making Bees Smaller'

The Guardian    1/20/14

Bumblebees exposed to a widely-used pesticide produced workers with lower body mass, scientists find

Bumblebees could be shrinking because of exposure to a widely-used pesticide, a study suggests. 

Experts fear smaller bees will be less effective at foraging for nectar and carrying out their vital task of distributing pollen. 

Scientists in the UK conducted laboratory tests which showed how a pyrethroid pesticide stunted the growth of worker bumblebee larvae, causing them to hatch out reduced in size. 

Gemma Baron, one of the researchers from the School of Biological Sciences at Royal Holloway, University of London, said: "We already know that larger bumblebees are more effective at foraging. 

"Our result, revealing that this pesticide causes bees to hatch out at a smaller size, is of concern as the size of workers produced in the field is likely to be a key component of colony success, with smaller bees being less efficient at collecting nectar and pollen from flowers." 

Pyrethroid pesticides are commonly used on flowering crops to prevent insect damage. 

The study, the first to examine the pesticides' impact across the entire lifecycle of bumblebees, tracked the growth of bee colonies over a four month period. 

Researchers exposed half the bees to a pyrethroid while monitoring the size of the colonies as well as weighing individual insects on micro-scales. 

They found that worker bees from colonies affected by the pesticides over a prolonged period grew less and were significantly smaller than unexposed bees. 

Findings from the study, funded by the Natural Environment Research Council (Nerc), appear in the Journal of Applied Ecology

Professor Mark Brown, who led the Royal Holloway group, said: "Bumblebees are essential to our food chain so it's critical we understand how wild bees might be impacted by the chemicals we are putting into the environment. 

"We know we have to protect plants from insect damage but we need to find a balance and ensure we are not harming our bees in the process." 

Currently a Europe-wide moratorium on the use of three neonicotinoid pesticides is in force because of their alleged harmful effect on bees. 

As a result, the use of other types of pesticide, including pyrethroids, is likely to increase, say the researchers. 

Dr Nigel Raine, another member of the Royal Holloway team who will be speaking at this week's national Bee Health Conference in London, said: "Our work provides a significant step forward in understanding the detrimental impact of pesticides other than neonicotinoids on wild bees. 

"Further studies using colonies placed in the field are essential to understand the full impacts, and conducting such studies needs to be a priority for scientists and governments." 

The scientists sprayed the pesticide on the bees' pollen feed at the concentration recommended for oilseed rape. 

Colony growth and reproductive output were monitored for up to 14 weeks.

Making a Beeline For The Nectar: How Patterns on Flowers Help Bees Spot Their First Nectar-Rich Flower

Science Daily   6/20/13

Bumblebees searching for nectar go for signposts on flowers rather than the bull's eye. A new study, by Levente Orbán and Catherine Plowright from the University of Ottawa in Canada, shows that the markings at the center of a flower are not as important as the markings that will direct the bees to the center.

The work is published online in Springer's journal, Naturwissenschaften -- The Science of Nature.

The first time bees go out looking for nectar, which visual stimuli do they use to identify that first flower that will provide them with the reward they are looking for? Orbán and Plowright test the relative influence of the type of floral pattern versus pattern position in a group of bumblebees that have never searched for nectar before i.e. flower-naive bees.

In a series of two experiments using both radio-frequency identification technology and video recordings, the researchers exposed a total of over 500 flower-naive bees to two types of patterns on...


Going Native!

Bug Squad - Happenings in the Insect World   By Kathy Keatley Garvey   4/24/13

The first thing you notice when you walk up to the Harry H. Laidlaw Jr. Honey Bee Research Facility on Bee Biology Road, UC Davis, are the natives.

Native plants, that is.

California golden poppies and phacelia are among the plants sharing the "Pollination Habitat" bed. The golden poppies literally light up the landscape. The phacelia, not so much.

The next thing you notice are the bumble bees, carpenter bees, honey bees...


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Bumblebees Use Logic to Find the Best Flowers

Science Daily  4/4/13

Scientists at Queen Mary, University of London and the Zoological Society of London (ZSL), have discovered why bees copy each other when looking for nectar -- and the answer is remarkably simple.

Despite their tiny brains, bees are smart enough to pick out the most attractive flowers by watching other bees and learning from their behaviour. By using simple logic, they see which coloured flowers are the most popular, and conclude that those of the same colour must also contain lots of energy-rich nectar.

"Learning where to find nectar by watching others seems fantastically complex for a tiny bee, but...

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Heavy Metal Bothers Bumblebees

(The following is brought to us by CATCH THE BUZZ (Kim Flottum) Bee Culture, The Magazine of American Beekeeping, published by A.I. Root Company.)  

PITTSBURGH—Beekeepers and researchers nationally are reporting growing evidence that a powerful new class of pesticides may be killing off bumblebees. Now, research at the University of Pittsburgh points toward another potential cause: metal pollution from aluminum and nickel.

Published in the journal Environmental Pollution, the Pitt study finds that bumblebees are at risk of ingesting toxic amounts of metals like aluminum and nickel found in flowers growing in soil that has been contaminated by exhaust from vehicles, industrial machinery, and farming equipment. The Pitt study finds that bumblebees have the ability to taste—and later ignore—certain metals such as nickel, but can do so only after they visit a contaminated flower. Therefore, the insects are exposed to toxins before they even sense the presence of metals.

"Although many metals are required by living organisms in small amounts, they can be toxic to both plants and animals when found in moderate to high concentrations," said Tia-Lynn Ashman, principal investigator of the study and professor and associate chair in Pitt's Department of Biological Sciences in the Kenneth P. Dietrich School of Arts and Sciences. "Beyond leading to mortality, these metals can interfere with insect taste perception, agility, and working memory—all necessary attributes for busy bumblebee workers."

Ashman and George Meindl, coauthor of the study and a PhD candidate in Ashman's lab, studied bumblebee behavior using the Impatiens capensis, a North American flower that blooms in summer. Its flowers are large, producing a high volume of sugar-rich nectar each day—an ideal place for bumblebees to forage. The blooms were collected from the field each morning of the two-week study and were of a similar age, color, and size.

To determine whether nickel and aluminum in the flowers' nectar influenced bumblebee behavior...


Plight of the American bumblebee: Disappearing?

ABC News/AP    By Seth Borenstein AP Science Writer   Washington March 1, 2013 

It's not just honey bees that are in trouble. The fuzzy American bumblebee seems to be disappearing in the Midwest.

Two new studies in Thursday's journal Science conclude that wild bees, like the American bumblebee, are increasingly important in pollinating flowers and crops that provide us with food. And, at least in the Midwest, they seem to be dwindling in an alarming manner, possibly from disease and parasites.

Wild bees are difficult to track so scientists have had a hard time knowing what's happening to them. But because of one man in a small town in Illinois in the 1890s, researchers now have a better clue.

Naturalist Charles Robertson went out daily in a horse-drawn buggy and meticulously collected and categorized insects in Carlinville in southern Illinois.

More than a century later, Laura Burkle of Montana State University went back to see what changed. Burkle and her colleagues reported that...



Bees Attracted to Contrasting Colors When Looking for Nectar

Science Daily    2/21/13

Flower colors that contrast with their background are more important to foraging bees than patterns of colored veins on pale flowers according to new research, by Heather Whitney from the University of Cambridge in the UK, and her colleagues. Their observation of how patterns of pigmentation on flower petals influence bumblebees' behavior suggests that color veins give clues to the location of the nectar. There is little to suggest, however, that bees have an innate preference for striped flowers.

The work is published online in Springer's journalNaturwissenschaften -- The Science of Nature.

Very few flowers are...