L'ÉTAT DE SANTÉ DES ABEILLES

À l’échelle planétaire, les abeilles sont en danger.  Non seulement cette situation est inquiétante par ce qu’elle nous indique sur la santé de nos écosystèmes, mais également en raison du rôle primordial de cet insecte pour la pollinisation de plusieurs de nos aliments. 

Un pollinisateur essentiel à notre alimentation ! 

La pollinisation assure la fécondation nécessaire à la reproduction sexuée des plantes à fleurs, un processus indispensable à leur survie. Tout comme le vent et de nombreux insectes, oiseaux et petits mammifères, l’abeille participe à la pollinisation. Son rôle est cependant exceptionnel alors qu’une abeille peut visiter, à elle seule, une moyenne de 700 fleurs par jour. 

On estime qu’environ 80 % des végétaux à fleurs sont ainsi butinés par cet insecte et que le tiers de nos ressources alimentaires dépendent directement de la pollinisation des abeilles. Ce service rendu à l’agriculture est estimé à une valeur de 32 à 78 milliards de dollars canadiens selon le Programment des Nations Unies pour l’environnement. 

Le déclin des abeilles constitue donc un enjeu crucial à la fois pour l’équilibre de nos écosystèmes et pour notre alimentation.

Syndrome d'effondrement des colonies 

Le syndrome d’effondrement des colonies (Colony Collapse Disorder) est le terme adopté par les scientifiques pour parler du déclin soudain et massif des colonies d'abeilles dans plusieurs régions du monde. 

Bien qu’il ne soit pas entièrement compris, plusieurs facteurs sont avancés pour expliquer ce phénomène. Il serait notamment attribuable à l’appauvrissement de la diversité végétale, au stress et aux carences nutritives liés à l’utilisation des abeilles pour la pollinisation de monocultures, à l’usage croissant des pesticides et à l’essor d’agents pathogènes. En plus de ces facteurs, les dommages causés par le varroa, un parasite originaire d’Asie, contribueraient à ce phénomène.

Bien que ce syndrome ne soit pas diagnostiqué au Québec, des pertes anormales d’abeilles sont néanmoins observées depuis le début des années 2000.  Malgré ces pertes importantes, le nombre de ruches en activité dans la province a crû de 33 % entre 1998 et 2010, en raison d’une demande croissante des services de pollinisation pour de meilleurs prix. 

Aussi, lorsque l'on parle des problèmes de santé des abeilles on parle davantage d'une dégradation de l'état de santé des colonies que d'une chute du nombre d'abeilles.

L’abeille, sentinelle de l’environnement 

Par son travail de pollinisation, son périmètre d’action et sa sensibilité à l’environnement, l’abeille agit comme baromètre écologique. À ce titre, elle est utilisée dans diverses recherches pour identifier et évaluer les taux de polluants, de biodiversité, de radioactivité et de bactéries présents dans certains écosystèmes. 

Aussi, l'état de santé actuel des abeilles ne devrait-il pas sonner l’alarme dans nos sociétés?

Agriculture urbane Montreal

Més

MEMÒRIES D'UNA ABELLA

Quan jo vaig néixer començava a despuntar la primavera en la vessant solana de les muntanyes prelitorals. Casa meva reposava en un indret idíl·lic, envoltada de flora mediterrània que feia les delícies de les abelles més exigents. Romaní, farigola i cap d’ase a principis de temporada i cirerer d’arboç, bruguerola i olivarda per tancar l’anyada.

memoriesabella.blogspot.com

Més

WHAT IS IT LIKE TO BE A BEE?

You’re a honeybee. Despite being around 700,000 times smaller than the average human, you’ve got more of almost everything. Instead of four articulated limbs, you have six, each with six segments. (Your bee’s knees, sadly, don’t exist.) You’re exceptionally hairy. A shock of bristly setae covers your body and face to help you keep warm, collect pollen, and even detect movement. Your straw-like tongue stretches far beyond the end of your jaw, but has no taste buds on it. Instead, you “taste” with other, specialized hairs, called sensillae, that you use to sense the chemicals that brush against particular parts of your body.

You’ve got five eyes. Two of them, called compound eyes and made up of 6,900 tiny lenses, take up about half your face. Each lens sends you a different “pixel,” which you use to see the world around you. The colors you see are different. Red looks like black to you and your three “primary” colors are blue, green, and ultraviolet. You detect motion insanely well, but outlines are fuzzy and images blocky, like a stained-glass window. (Your three other eyes detect only changes in light to tell you quickly if something dangerous is swooping your way.)

Now that you’re a honeybee you can do all kinds of things you couldn’t before. Your four wings move at 11,400 strokes per minute. You can sense chemicals in the air. You’re fluent in waggle dance, so you’re able to tell the other members of your colony where the nectar supplies are. But how much does any of this tell us about what it actually feels like to be a bee?

We all know what it’s like to be ourselves—to be conscious of the world around us, and be conscious of that consciousness. But what consciousness means more generally, for other people and other creatures, is a hot potato tossed between philosophers, biologists, psychologists, and anyone who’s ever wondered whether it feels the same to be a dog as it does to be an octopus. In general, we think that if you have some kind of unique, subjective experience of the world, you’re conscious to some extent. The problem is that in trying to envisage any consciousness besides our own, we run into the limits of the human imagination. In the case of honeybees, it’s hard to know if interesting behavior is reflective of an interesting experience of the world or masks a more simple stimulus-response existence. The lights are on, but is anyone home? To examine these questions means to take a ride on that hot potato—from philosopher to scientist and back again and again and again.

More and more, scientific research seems to suggest that bees do have a kind of consciousness, even as myths and misconceptions about their capacities persist. In a recent TED Talk, cognitive scientist Andrew B. Barron of Macquarie University in Sydney, Australia, described how he had had to be lovingly “talked down” from a “pearl-clutching” moment after someone asked him whether bees actually have brains. They do, of course.

Understanding what their consciousness might look or feel like is probably a fool’s errand. It’s really hard to imagine what it’s like to be almost anything or anyone other than what you are, says philosopher Colin Klein, also from Macquarie University, who has worked extensively alongside Barron. With people, it’s much easier. “You can talk to them, you can read fiction, there are a lot of things you can do—but it takes a certain amount of work to get into that space and in particular to realize what you experience, what you don’t experience, what your horizons look like,” he says. But the more different the experience of the organism you’re trying to imagine is, the harder it becomes. “You can start to think at least in what senses the experience of something like a bee might be different from ours”—how they structure the world around them, say, or whether they experience “space” the way we do.

The philosopher Thomas Nagel’s famous 1974 essay, “What Is It Like to Be a Bat?” suggests that being “like” something else is possible only if the target is conscious of the world around it. “The fact that an organism has conscious experience at all means, basically, that there is something it is like to be that organism,” he writes. Or, “fundamentally an organism has conscious mental states if and only if there is something that it is to be that organism—something it is like for the organism.” On top of that mindscrabble, our ability to imagine ourselves as another being is limited by the world that we know—as people. We might be able to imagine having webbed arms and hands, like a bat, or five eyes, like a bee, but the specific senses and abilities these animals possess are frankly inconceivable. “I want to know what it is like for a bat to be a bat. Yet if I try to imagine this, I am restricted to the resources of my own mind, and those resources are inadequate to the task,” he adds. Moreover, “I cannot perform it either by imagining additions to my present experience, or by imagining segments gradually subtracted from it.”

Despite these difficulties, what we want to know, Klein and Barron wrote in an op-ed in The Conversation in 2016, is whether bees and other insects “can feel and sense the environment from a first-person perspective.”

It seems likely that there are lots of different kinds of consciousness, of varying levels of complexity. As human beings, not only are we aware of ourselves and the world around us, we’re also aware of that awareness. A step down in complexity might lack that awareness of self-awareness. And a step down from that might be limited to a distinctive experience of the external world only.

Such a simple ladder may not be the best way to organize this kind of complexity, says David Chalmers, a leather jacket-wearing Australian philosopher at New York University best known for his work in philosophy of mind—a branch of philosophy that asks these kinds of questions. “But there are probably different ways of arranging states of mind, or consciousness, in a hierarchy,” he says. What’s harder to distinguish is the precise point where consciousness ends, and what the light switch, “on-off,” moment might be, further down the evolutionary chain. “It’s awfully hard to see what a borderline case of being conscious would be,” he says, even while it’s not that hard to know what a borderline case of being alive might look like, as in a virus. “It would sort of feel like something,” he says, trailing off in thought, “but not.”

So far as bee consciousness goes, however, he thinks there are likely to be some factors in consciousness that we share, like vision, and some that we don’t at all, “whether it’s sensory systems that humans have that bees don’t have, or whether it’s things more like concepts, like language, that give us a kind of consciousness that bees don’t have.”

Klein is more specific. “We think that bees have experiences that feel like something to the bee,” he says. “We don’t think the bees are aware of having experiences that feel like something to them. The bee is not going round saying to itself, ‘Gee, it’s a lovely day, look at that flower.’ It doesn’t have any of these more sophisticated, reflexive kinds of consciousness.”

Still, despite having a brain that is a fraction of the size of even the tiniest mammal’s, bees seem capable of some incredibly complex behaviors and mental gymnastics. Studies over the last few decades have revealed them to do everything from having a concept of zero to experiencing emotion, from tool use to social learning. If you give them cocaine, they dance more vigorously and tend to overestimate how much pollen they’ve foraged. If they watch a plastic bee scoring goals with a soccer ball, they can follow suit for a sugar water reward. Wouldn’t these complex behaviors be enough to assume some kind of consciousness? Not necessarily, says Barron. “Honeybees are unusual among the insects in that they have a whole list of clever things that they are able to do,” he says. “And some people would say that that means that they are more likely to be conscious. I disagree with that.”

Think of all the other things able to perform complicated tasks that we’re pretty sure aren’t conscious. Robots do everything from juggle to play the piano, but, as far as we know, are “dark” inside. Like bees, Roomba vacuum cleaners make decisions, navigate around the world, and adapt—but there’s probably nothing it’s “like” to be one of them. And plants have been shown to have a kind of memory: Over time, for example, they can learn that being repeatedly dropped isn’t anything to freak out about. But few suggest they possess consciousness.

“I think this is one of the problems with the behavioral approach, is that it encourages this looking for very clever things,” says Klein. “Whereas if consciousness is a widespread phenomenon, you should expect that it might be in a lot of different types of things that don’t necessarily do the things that we take to be markers of consciousness.”

If behavior can’t enough tell us about the inner life of a bee, perhaps the structure of their sesame seed–sized brains can. In a human brain, key studies suggest consciousness lies in the midbrain, an evolutionarily much older section. In a study published last year, Barron and Klein investigated the structure of the bee brain, which seems to be made up of similar bits to our own, with a region responsible for similar tasks. “It’s smaller, it’s organized differently, it’s different-shaped, but if you look at the kind of computations it does, it’s doing the same sort of things as the midbrain,” Klein says. “So if you think in humans the midbrain is responsible for being conscious, and you think this is doing the same kind of thing, then you ought to think insects are conscious as well.”

This biological approach opens up consciousness to a variety of other organisms that don’t do the clever things that bees do, like beetles or potato bugs. They might be less obviously interesting, but that doesn’t make them less likely to be conscious. The technology that allows us to examine insect brains on a neuron-by-neuron level is very new, Barron says. “If they really are instinctive, then we’re learning something about what the insect brain is capable of. If they’re not, then we’re learning something more profound.”

The technology also allows us to map the brains of organisms that we think probably aren’t conscious, and assess what they lack. Caenorhabditis elegans is a roundworm commonly used in scientific research. In recent years, scientists have developed a connectome—a sort of complex brain map—for this tiny soil-dweller, which measures barely a millimeter in length. “They have 302 neurons,” says Klein, compared to a bee’s 960,000 and a human’s 86 billion. “Those [worms], we think, are actually very much like robots, like complicated robots.” If exposed to a particular stimulus, they respond in a particular, predictable way. “Unless there’s some kind of danger, and then it does that, unless it’s hungry, and then it does this—so you can really map out what it’s going to do.” In bees, he says, there seems to be a kind of qualitative shift, in which the brain is somehow more than its connections.

All of this neurobiology is beginning to paint a picture—that it feels like nothing to be a C. elegans, or a robot, or a plant, but it probably feels like something to be a bee. If that’s the case, it is still not known where, between the roundworm and the honeybee, that awareness switches on, if it does. While neurobiology is a very important part of the story, says Chalmers, “it may not settle the issue of consciousness. You very frequently find a situation where two people might agree on the neurobiology of a given case, but disagree on what that implies about consciousness.” He gives the example of fish, and the ongoing discourse about whether their neurobiology suggests that they do or do not feel pain. “Knowing the neurobiological facts doesn’t necessarily settle the question.”

We can try to imagine what it’s like to have six hairy legs, or see in pixels, or crave nectar. We can even try to imagine what it’s like to be part of a hive, a superorganism with motivations of its own. But what it’s actually like to be a bee—its subjective experience of the world—is going to remain elusive. But we’re starting to figure out that it’s probably like something. And that’s not nothing.

Atlas Obscura

Més

YOU SHOULD THINK OF HUMMINGBIRDS AS BEES WITH FEATHERS

What’s small, buzzes here and there and visits flowers?

If you said bees or hummingbirds, you got it. And you wouldn’t be the first if you mixed the two up. In Medieval Europe, some called bees the smallest birds. In Chinese and Japanese, the words for hummingbird translate into “bee bird.” Today we call the smallest hummingbird — weighing less than a penny and only a bit larger than the biggest bee — the bee hummingbird.

And now a group of researchers say we should embrace our history of lumping the two together. The way scientists study bees could help them study hummingbird behavior, too, they argue in a review published Tuesday in Biology Letters.

Scientists first compared the two back in the 1970s when studying how animals forage. The idea is that animals use a kind of internal math to make choices in order to minimize the work it takes to earn maximum rewards. Researchers at the time focused on movement rules, like the order in which they visited flowers, and where flowers were located relative to others. It was “almost like an algorithm” for efficient foraging, said David Pritchard, a biologist at the University of St. Andrews in Scotland who led the review. Hummingbirds and bees had similar solutions.

You’re a Bee. This Is What It Feels Like.

We’re taking you on a journey to help you understand how bees, while hunting for pollen, use all of their senses — taste, touch, smell and more — to decide what to pick up and bring home.

But the study of optimal foraging, as it was called, overlooked what animals learned about their environments. Bees decipher which flowers are more rewarding than others. They learn about color and how to manipulate a flower among other information. Decades before the concept of optimal foraging, Frank Bené, an American ornithologist, discovered that hummingbirds learned about color too, contrary to the belief that they were innately attracted to red. Hummingbirds also remembered locations of feeders that he moved in his garden.

As the field of animal cognition emerged, hummingbird and bee research diverged. Neuroscientists and behavioral ecologists developed ways to study bee behavior in naturalistic settings. Hummingbird researchers compared hummingbirds to other birds and borrowed methods from psychology to study their capacity to learn in the lab.

To be fair, hummingbirds and bees differ. Hummingbirds have more advanced eyes and brains than bees. Olfaction, while important for bee memory, has historically been ignored in hummingbirds. Honeybees and bumblebees are social; hummingbirds typically aren’t. Bees rely solely on flowers for nectar and pollen; hummingbirds also eat insects, which may require that their brains work differently, Beth Nichols who studies bee behavior at the University of Sussex in Britain wrote in an email.

But however they perceive or process information, they both experience similar information, Dr. Pritchard said. Bees and hummingbirds approach flowers that distribute food predictably in time in space, so he and his colleagues have turned to these animals’ commonalities.

Can You Pick the Bees Out of This Insect Lineup?

How can we save the pollinators if we don’t even recognize them?

In day-to-day foraging, for instance, hummingbirds may rely on more of a bee’s-eye view than a bird’s-eye view. Like other birds, they rely on landmarks, distances and directions to make maps when migrating long distances, but they don’t use these cues to find flowers. Move a flower just an inch or so away from where a hummingbird thought it was and it will hover over the flower’s original location. Dr. Pritchard is investigating if, like bees, hummingbirds engage in view matching — hovering, scanning snapshots of a place to its memory and using those as references later.

Like bees, hummingbirds also create repeated routes between flowers during feeding, as a trapper might check traps. In the lab they learn arbitrary sequences, following one flower to the next over hundreds of trials. But they won’t do it in nature. Taking methods from bee work, however, researchers put hummingbirds in an arena of artificial flowers that refilled with nectar like flowers in the wild. Like bees that find the fastest way to nectar-rich flowers on their own, hummingbirds also found the most efficient paths, rather than following the order in which researchers had presented flowers

Ultimately, Dr. Pritchard said, advances in our understanding of an animal can come from unexpected places.

“The idea of getting inspiration from insects to study birds and mammals is something that doesn’t happen very often.”

By  JOANNA KLEIN - THE NEW YORK TIMES

Més