09 de gener 2021

TENEN FRED LES ABELLES?

 

Alguns apicultors es pregunten si les abelles pateixen amb les nevades... la veritat és que no. De fet, la majoria d’animals són molt resistents al fred i són capaços de resistir llargs períodes de baixes temperatures, només cal una condició: un bestiar ben gras. Sigui com sigui, els greixos seran reservoris energètics a llarg termini i les abelles seran capaces de convertir el rebost mel·lífer de glúcids immediats en lípids futuribles, tota una garantia per arribar en condicions a la propera primavera.

PER QUÈ L'ABELLA ÉS EL SÍMBOL DE MANCHESTER?

 

Per explicar-ho cal recular fins els segle XVIII i XIX, quan aquesta ciutat es trobava en plena revolució industrial. Durant aquest període es van crear moltes indústries, però una de les més comunes eren les anomenades Cottoncity (ciutats del cotó). Dins d’aquestes fàbriques hi treballaven un conjunt d’operaris molt eficients i que hom relaciona amb la tasca desenfrenada de les abelles dins d’un rusc. A mitjans del segle XIX el símbol de l’abella es va incorporar oficialment a l’escut de la ciutat.

08 de gener 2021

10 ANYS D'ECOLLUITA

 

Aquest mes de gener de 2021 celebrem els 10 anys de la creació del diari Ecolluita, un bloc gestionat amb més o menys encert per tot un conjunt d’apicultors i abellaires que ens han obsequiat amb opinions, articles i notícies del món de les abelles. Si el visiteu, https://ecolluita.blogspot.com/ hi trobareu més de 1800 entrades, organitzades en 90 temàtiques diferents. Estem contents de la feina feta i volem continuar treballant, de forma independent i altruista, al servei de les nostres companyes les abelles. Per molts anys!

GTR

 

Ja comença un nou any i com cada gener-febrer cal actualitzar els censos dels nostres ramats d’abelles. Aquest any però, hi ha la novetat del GTR (Gestió Telemàtica Ramadera), una aplicació on-line del Departament d’Agricultura i Ramaderia que et permetrà actualitzar censos sense necessitat d’assistir personalment a la teva oficina comarcal. L’actualització obligatòria continua essent com a mínim un cop l’any, però la versió telemàtica ho farà tot molt més fàcil. Bona feina!!!

07 de gener 2021

LA MELIPONICULTURA

 

L’apicultura és l’art de tenir cura de les abelles del gènere Apis. La meliponicultura és per tant tenir cura d’un altre tipus d’abelles, les que trobem dins la tribu Meliponini. Aquesta activitat ramadera té una llarga tradició en el continent Americà del sud, Austràlia, Àfrica i el sud-est asiàtic. Són abelles mal anomenades “sense fibló”, doncs en tenen, el que passa és que és molt petit o bé els treballadors són mascles, i aquests sí que no tenen fibló. La mel és emmagatzemada en petits nius, on la reina d’aquestes abelles s’alimenta i fa una posta més o menys contínua. Melipona beecheii és una de les principals espècies de Mèxic, abella sagrada del maies.

 

05 de gener 2021

VESPES MEL·LÍFERES

 

Dies enrere explicava que les abelles provenen evolutivament de les vespes. Avui us explico que les abelles no són els únics insectes que fan mel. Existeixen un conjunt de 16 espècies de vespes del gènere Brachygastra que també recol·lecten nèctar i el transformen en mel. A diferència de les abelles, i com bones vespes que són, els seus nius no són de cera sinó de paper. Brachygastra mellifera és una d’aquestes vespes mel·líferes.

04 de gener 2021

LLUITA CONTRA LA VELUTINA

 

La lluita contra la Vespa velutina cal que combini sempre dos elements: per una banda els xarops i per l'altra els protectors de trescadors. Pel que fa als xarops, la barreja de suc de nabius i cervesa negra sembla ser la millor de totes. Per altra banda, els protectors buscaran donar espai de vol a les abelles, evitant així el col·lapse del trescador i la inactivitat de les recol·lectores.

02 de gener 2021

RUSCOS ENTRE TOMBES


L’apicultura urbana pot ser un bon instrument per naturalitzar poc a poc les grans ciutats. El nostre país hauria d’emmirallar-se en aquells que tenir abelles enmig d’edificis i terrats fos la cosa més normal del món. I com no, posats a buscar zones verdes i desaprofitades, uns quants metres quadrats del cementiri poden ser perfectes. Només cal voluntat política, i d’això, els que manen, ben poc.  

 

How an Urban Beekeeper Spends His Sundays

Nick Hoefly tends to bees among the tombs of Green-Wood Cemetery in Brooklyn. Happy Halloween.

www.nytimes.com


CAUS EN ESTRATS ARGILOSOS

 

Les abelles solitàries elaboren caus en estrats argilosos. Aquests nius de fondària escassa, tenen una cambra en el seu tram final, on es dipositaran un o pocs ous a fi de perseverar en la continuïtat de l’espècie. Realitzada la posta i assegurada la seva alimentació post-eclosió, els orificis seran bloquejats amb una mica de fang premsat.

LA TRAVESSA DEL DESERT

 

Ja han passat masses anys des de la darrera entrada en aquest bloc, ... una travessa del desert massa llarga i plena de despropòsits i masses desenganys.

És per això, que a partir d'avui m'hi poso amb la ferma voluntat de reactivar aquesta associació, reconvertir-la en quelcom diferent, lligat sempre al nostre amor infinit cap a les abelles. Deixem, doncs, de banda, la pretensió de ser una associació més, i enfoquem el futur amb la voluntat de construir ponts i fomentar la divulgació.

Ara veurem com està el pati... 

Esteve - Antic veterinari de l'Assoc. Col·lectiu Abellaires

01 de gener 2021

FA FRED I JO TREBALLO

 

Els borinots, bagots, bagarros, bufaforats… i tots els noms del món (Bombus terricola) ... un meravellós insecte, de cos pilós, capaç de treballar incansablement tot i el fred que fa en un dia com avui. Increïbles i necessaris, doncs la seva tasca pol·linitzadora és insubstituïble. Sovint quan els observo, no puc resistir la temptació d’acaronar-los i gaudir per uns instants del seu exquisit pelatge. Ells, nobles i determinats, mai buscaran la confrontació, canviant de flor en un sorollós vol.

27 de desembre 2020

DESABELLAMENT

 

La síndrome del desabellament (Colony Collapse Disorder) és una alteració sanitària que està posant en perill la viabilitat de les abelles. Alguns científics parlen d’un procés infecciós, altres d’un fenomen lligats al canvi climàtic, alguns d’una deficient nutrició, i encara d’altres acusen del procés als pesticides. Al final, sigui el que sigui, les abelles es moren i tot plegat fa pensar en un conglomerat multifactorial que està alterant la sort d’aquests insectes. Les abelles són bioindicadors, molts sensibles a qualsevol canvi, sigui químic, físic o biològic. Tremolem!



26 de desembre 2020

BORINOTS HIVERNALS

 

L’arribada de l’hivern implica sempre una menor activitat de les abelles mel·líferes, tot gaudint del refugi i reserves de les bresques dins del rusc. Per contra, les abelles solitàries aprofiten qualsevol ullada de sol per treballar, incansables en les poques flors que trobem en l’estació freda, cirerer d’arboç, nesprer, espígols i romanís arrecerats... i qualsevol petita font de nèctar que els pugui satisfer la seva famolenca curiositat. De cos pilós, un abric imprescindible en els dies més curts de l’any.

25 de desembre 2020

L'OR DE LES ABELLES


El pròpolis és l’or de les abelles, un producte antisèptic obtingut a partir de la transformació de les resines dels arbres. Lògicament, de la mateixa manera que no hi ha dues mels iguals, tampoc trobarem dos pròpolis idèntics. Cada col·lectiu d’abelles fabrica la seva pròpia barreja de resines, una formulació màgica que depèn de la qualitat de biodiversitat present en un indret però també de la memòria genètica d’aquest meravellós insecte.

POL·LINITZADORS ENVERINATS

 

Estudis edafològics certifiquen que els sòls dels camps de conreus intensius estan massa plens de pesticides. Cal recordar que no totes les abelles viuen en ruscos, i que les abelles solitàries, les grans pol·linitzadores d’aquests conreus sovint fan els seus nius en el terra, i per tant serien les grans damnificades d’aquests nivells elevats de productes neurotòxics. Un drama!


Pollinating bees may be exposed to lethal levels of neonics in soil on southern Ontario farms: study

New research suggests ground-nesting bees may be exposed to lethal levels of pervasive insecticides found in soil on farms across southern Ontario.

University of Guelph environmental sciences professor Nigel Raine and PhD student Susan Chan examined the hoary squash bee that feeds on the nectar and pollen of squash, pumpkin, gourds and melon, and is a crucial pollinator for those crops.

They estimated 36 per cent of the bee population studied encountered lethal doses of one major neonicotinoid – clothianidin – in the soil at 18 commercial squash fields in a region stretching from Peterborough, Ont., to the tip of southwestern Ontario.

globalnews.ca

24 de desembre 2020

XUCLAR O LLEPAR?

 

Els científics han descobert que les abelles poden utilitzar la seva llengua de dues maneres diferents depenent de la viscositat del nèctar. Quan les pluviometria és escassa les plantes generen un nèctar molt concentrat de sucres i les abelles utilitzen la seva llengua com si fos una cullera, tal i com ho fa un gos o un gat. En canvi, quan els nèctars són molt líquids, escullen l’estratègia de la succió.

 

Honeybees consume nectar by sucking and not just dipping their tongues, scientists discover

For a century, scientists have known how honeybees drink nectar. They lap it up.

 

They don’t lap like cats or dogs, videos of whose mesmerising drinking habits have been one of the great rewards of high speed video. But they do dip their hairy tongues rapidly in and out of syrupy nectar to draw it up into their mouth. For the last century or so, scientists have been convinced that this is the only way they drink nectar.

 

Scientists have now discovered bees can also suck nectar, which is more efficient when the sugar content is lower and the nectar is less viscous. A high speed video of bees drinking a nectar substitute in a lab shows that not only do honeybees have this unexpected ability, they can go back and forth from one drinking mode to another.

 

Jianing Wu, an engineering and biophysics specialist, at Sun Yat-sen University in Guangzhou, China, and the senior researcher on the experiment, said that while honeybees excel at feeding on highly concentrated nectar, “we find that they can also flexibly switch the feeding strategy from lapping to suction”. He and his colleagues reported the results on Wednesday in the journal Biology Letters.

 

David Hu, a professor at the Georgia Institute of Technology, who supervised some of Mr Wu’s earlier research but was not involved in this experiment, said: “We thought that insects’ mouths were like tools in your kitchen drawer (straw, fork, spoon), with single uses.”

 

Alejandro Rico-Guevara, who runs the Behavioural Ecophysics Lab at the University of Washington, Seattle, and studies nectar feeding in birds, also worked on the project. He said this flexibility in nectar-drinking behaviour means that although bees prefer the more syrupy nectars, they can efficiently feed from flowers whose nectar is more watery. “This has implications at many different scales, from pollination, for our food, all the way to the role they have in natural ecosystems,” he said.

 

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What Mr Rico-Guevara found most interesting was that the bees are so sensitive to the viscosity of the nectar that “they switch at the exact point you would expect, to get the best reward for the energy invested”.

 

The honeybee tongue is adapted perfectly to lapping syrupy nectars. Once the tongue is dipped into thick nectars, Mr Wu explained, “approximately 10,000 bristles covering the tongue erect simultaneously at a certain angle for trapping the nectar”. The bee then pulls its tongue back into its proboscis, which is really a part of its mouth, and a pumping mechanism in the head sucks the nectar off the tongue.

 

When the viscosity changes so that the nectar is less thick, the bees let their tongues stay in the nectar and suck it up into their mouths, apparently using the same pumping mechanism.

 

Mr Hu said: “The result makes perfect sense because honeybees are already known as generalists.” They are not limited to feeding on only one type of flower like some other species of bee.

 

The bees have been flexible all along. It was the scientists who were stuck on one idea.

 

New York Times

22 de desembre 2020

ABELLA SOLITÀRIA

 

Abella solitària (Halictus scabiosae) damunt d’una flor de card marià. Tothom coneix l’abella de la mel (Apis mellifica), però només és una de les 20.000 espècies que podrem trobar a la biosfera. D’aquestes, les tres quartes parts són solitàries, o sigui viuen en parella, fugint de les societats matriarcals que trobem en els ruscs o arnes.

ABELLES I DINOSAURES

Els primers dinosaures tenen una antiguitat d’uns 245 milions d’anys i les abelles d’uns 100 milions d’anys. Aquest fet ens parla d’una convivència aproximada de 35 milions d’anys fins que un asteroide va extingir els majestuosos rèptils ara fa 65 milions d’anys.

Yes, and in fact they shared the planet for millions of years before a mass extinction wiped out dinosaurs, but spared bees and many other living things.

How do we know that bees were around when dinosaurs still roamed the Earth? The main evidence comes from fossils – the mineralized remains of long-dead organisms. 

A lot has to go right for a dead creature to become a fossil. It has to be quickly covered by sediment before a scavenger has a chance to eat it – and the sediment has to be just right to preserve the details of its body. Then, millions of years later, that same sediment, now rock, has to become exposed through erosion so that people can find it and study it. When things go right, even a single fossil specimen can reveal a great deal.

Extinct animal species, known only from fossils, often look very different from creatures alive today. But scientists can almost always identify which branch of the tree of life they belong to, and thereby identify how they are related. The dinosaurs – T. rex, Velociraptor, Triceratops and the rest – seem almost fantastically weird, but their fossilized skeletons enable us to recognize them as reptiles.

The same is true for insects. Scientists can identify something as a bee by its distinctive features, such as the structure of its antennae, the shapes of its major body parts, and the pattern of veins in its wings. 

Using these features, scientists have identified fossils of dozens of species of extinct bees. Some look like modern bees; others look quite different but are still recognizable as bees. 

The oldest fossil bees look a lot like wasps. In fact, bees are thought to be a branch of the wasp family tree that evolved a vegetarian lifestyle, getting food from flowers instead of eating other insects. 

The most exquisitely preserved fossil bees have been found in amber, which is fossilized plant sap. Perhaps these bees became trapped in sap while trying to collect it for constructing their nests – something many bees do today.

But how do we know how old any of these fossils are? It turns out the rocks that encase them have a built-in clock that reveals their age. The most common “radiometric clock” relies upon the decay of uranium into lead. 

By knowing how much uranium and lead were present when the mineral rock was formed, how much is present now, and how fast this decay happens, we can reliably estimate the age of many ancient rocks, which tells us how long ago fossilized organisms lived.

The earliest dinosaurs appeared on earth around 245 million years ago, and dinosaurs were last seen when an asteroid hit the earth around 65 million years ago. The oldest fossil bees date from about 100 million years ago, which means bees and dinosaurs lived together for at least 35 million years, and possibly much longer.

Did a dinosaur ever get stung chomping into a plant where bees were nesting or collecting nectar and pollen? We can’t know for sure, but fossils tell us it is very possible.

theconversation.com 

 

20 de desembre 2020

DESPREOCUPACIÓ APÍCOLA

Passen els mesos, les estacions i els anys... i ningú es preocupa de l’estat sanitari de les nostres abelles. Vivim en un país sense rumb, sense un programa sanitari modern i un sector apícola poc fiable i de nul criteri ètic. Les abelles es moren, la vespa asiàtica ens atonyina, la varroa persisteix... i ningú diu res? Hom pensa que alguna cosa no estem fent bé... però aquells fenicis que mercadegen amb mel la situació actual ja els hi va bé. Quina pena!


 

LES ABELLES TENEN CARÀCTER

 

No totes les abelles tenen el mateix caràcter, existint diversitat de comportaments, des del més atrevit fins al més conservador. L’estudi va utilitzar poblacions d’abelles, i amb marcatges toràcics van poder valorar com en la gran explosió demogràfica apareixien escamots d’abelles especialment curioses. Aquestes exploradores serien molt interessants en processos d’eixamenada, quan la recerca d’una nova llar i de noves fonts d’aliment són qüestió de vida o mort.

Some bees are born curious while others are more single-minded – new research hints at how the hive picks which flowers to feast on

 

When you try to pick a restaurant with a group of friends, how do you decide? Your curious friend wants to try the new place, while your focused friend wants to go to the old faithful. One friend is insistent, while the other is more quiet. Ultimately, the focused vocal friend convinces the group by saying, “I am telling you, this is the best place. It’s a sure thing – we gotta go!”

 

Just like people, honey bees vary in how they seek out food and communicate where to go. As a biologist, I study collective behavior, especially how groups make decisions. My colleagues and I have discovered some individual bees are seemingly born with a predetermined foraging style – they can be either focused foragers or curious foragers. Having different approaches to collecting food turns out to be advantageous for large colonies that rely on a changing food landscape.

 

Explorers and exploiters

 

As animals collect food, they must balance exploring for new food with exploiting already known food sources. Individual animals have to do one or the other, switching between exploring or exploiting. In collectives, like honey bee colonies, foragers can split the work and do both at the same time.

 

As honey bees forage for nectar and pollen, they learn a lot of information about the flowers they visit, such as their smells, colors and locations. Some bees become extremely focused on information associated with food, ignoring any new information – similar to selective attention in humans. Conversely, other bees exhibit a learning behavior marked by curiosity. They are interested in learning about new food sources, not just familiar ones.

 

True to type

 

My colleagues and I became interested in how bee colonies manage and act on these two types of information. To answer this question, we first figured out how to breed curious bees and focused bees.

 

We tested female queens and male drones to see if they were curious or focused, and then used artificial insemination to breed a curious queen with a curious drone, and a focused queen with a focused drone. Typically queens mate with 12 to 15 different drones and create genetically diverse workers, so using a single drone helped keep workers genetically uniform.

 

A bowl filled with several hundred bees, all marked with a blue dot on the thorax.

One-day-old curious bees marked blue. Sebastian Scofield, CC BY-SA

 

Once we had populations of genetically curious and focused bees, we had to verify they would not be influenced by their social environment. We did this by placing bees in colonies of either their own learning type or one with an assortment of learning types. (We kept track of who was who by marking them with paint on their thorax as soon as they were born.) Sure enough, regardless of the social group the bees experienced, they exhibited the same learning behavior we observed in their parents.

 

Familiar food versus novel food

 

Next, we created colonies of all focused bees, all curious bees or a 50/50 mix of focused and curious bees – then watched how they foraged.

 

We gave them a choice between two food locations: a familiar, reliable food location that stayed in the same spot for four days or a new food location that changed odor, color and location every day. Both locations contained the same quality and quantity of food. We marked bees on their abdomens as they visited the feeders so we knew which ones they had been to and which ones they were revisiting.

 

Five bees perched on the edge of a red feeder, sipping nectar.

Researchers marked the bees visiting this feeder with yellow. Chelsea Cook, CC BY-SA

We discovered the focused colony quickly found the familiar food location and exploited that eatery all week, rarely visiting the novel food option.

 

The curious colony, as expected, visited the novel and the familiar food locations equally, showing no preference.

 

Interestingly, the 50/50 mixed colony ended up acting more like the focused colony, using the familiar feeder and paying little attention to the novel feeders. We observed the curious bees in the mixed colony shifted their selected behavior by visiting the familiar feeder more than the novel one. Why?

 

The bee in the middle communicates the location of food using the waggle dance.

Dancing up a storm

 

When honey bees find a good source of food, they use the waggle dance to direct their nest mates. This dance communicates the distance to and direction of a nutritious meal, as well as its perceived quality. When we looked at waggle dance behavior in the 50/50 colony, we saw the focused bees were dancing more intensely – performing 0.59 turns per second, significantly faster than the curious bees’ 0.52 turns per second. Just like your vocal, excited friend, the focused bees attracted more followers, so more bees were recruited to the familiar, reliable feeder.

 

Because curious bees are interested in everything, including new information about possible food locations, they are perfect listeners and are easily convinced to visit the chosen feeder of their enthusiastic nest mates.

 

Our future work will investigate how these foraging dynamics work in a changing food landscape – one where food runs out. If a source is depleted, will the focused bees turn their attention to the curious bees, who already know where other foraging locations are?

 

This research suggests successful societies make better decisions when members, by virtue of their innate learning styles, collect and communicate a diversity of information – whether they are bees looking for nectar or friends trying to decide on a restaurant. Diversity of learning behavior in individuals may help social groups adapt to shifting global environments.

theconversation.com