Dieses Blog ist jetzt geschlossen

Es sieht jedoch so aus, als würden mir die Bienen noch ein bisschen erhalten bleiben. Mehr dazu bald!
Ich höre auch nicht auf zu bloggen, sondern werde auf The Viable Blog weiter über Bienen und Agrarthemen schreiben – und was immer mir sonst noch in den Sinn kommt. Auch auf Twitter werde ich weiterhin unter @scout_bee unterwegs sein.
Euch allen vielen Dank, es war schön mit euch, und ich hoffe, wir sehen uns auf der anderen Seite wieder!

Wohlan!

Kerstin

Well, what can I say? Maybe this: If the honey bees are anything remotely as persistent as this quote, we wouldn’t need to worry about them:

“If the bee disappears from the surface of the Earth, man would have no more than four years left to live.”

As Nils pointed out and others did too: Einstein most likely never said this.

Still: when you follow the bees through the media, hardly a week goes by without someone referring to this “quote”. Most recently, I met it in a brochure by the German Ministry for Agriculture.

At least they carefully marked it as “attributed to Einstein”, but apparently they couldn’t resist to use it despite its doubtful origins.

Neither could we. In the beginning, when we started out on this project, we had this “quote” on our website, too. It just so perfectly sums up the importance of our little friends and the concerns that many people have about them. Maybe too perfectly.
It was only after some of the bee-people we are working with raised doubts about its authenticity that we set out to corroborate the source. We should have checked before.

But even if the quotation has to be considered a fine piece of fiction, the importance of bees is not. It’s just… more complicated. As Keith S. Delaplane, an Entomolgist at the University of Georgia, writes;

“Does human life depend on bee pollination? No. To what extent does the quality of human life depend on bee pollination? Well, it depends on where you live and what crops we’re talking about.”

He also writes:

“I think bee advocates do their cause a disservice when they stoke the flames of hyperbole and sensationalism. Much better to pose the question as a quality of life issue. To the extent that we value a diverse food supply with minimized trauma to the environments where it is produced, we will place a high value indeed on honey bees and other pollinators.”

There are no simple answers. At least not to this one. Just careful thinking and trying to see the whole picture. We are working on it.

Update (May 23, 2011): The latest encounter just happened (a sweet one though): A love affair with bees (at 1:15 min). Thanks Stephanie!

It does! But if you prefer the smart word: it’s hygroscopic. It attracts water.

And where is water, there is rot.
Which is a problem when you are an insect that relies on pollen to feed its brood and therefore needs to store pollen for weeks, if not months. You may be more or less okay when in a desert or at least able to avoid the rainy season – but in our friendly fertile temperate zones, you’re not.

Still, they are here. Plenty of them. Mason bees and leafcutter bees and carder bees and many more.

In their new paper, Christophe Praz and his colleagues suggest a scenario for just how this could have happened:

Before the bees began to feed pollen to their brood (i.e. before they actually became bees) they were something similar to today’s apoid wasps (Grabwespen). They were hunting other insects, paralysed their victims and dragged them into the broodnest where their prey would stay alive for several weeks before being consumed by the larvae.
You may find this disgusting or not, but keeping your food alive until consumption is definitely a good way to keep it fresh.
And there is nothing „primitive“ or old-fashioned about it. There are still plenty of wasps around who do exactly this. But this method does have its costs. Hunting takes time, it’s not without risks, chances to find prey are limited and so on. So when the flowering plants arrived and offered pollen as an alternative source of protein, the bees’ ancestors skipped their carnivorous habits and became all out vegetarians. Which – as we all know – turned out to be a smart move.

But before the flowers and the bees could become one of the biggest success stories on the planet, there was one more innovation needed.

From gene sequencing data and the analysis of diversification rates and biogeography, Praz and his colleagues conclude that for a long time bees had been restricted to arid evironments and that it was only after the „invention“ of traits to impregnate the broodchamber that they were able to achieve their impressive diversity (3900 species today) and worldwide expansion.

They also argue that nest-lining behaviour with foreign material was „invented“ only once within the megachilid bees, some 90 to 100 million years ago (as marked by the green star in the figure below).

[Click picture to enlarge]

So flowering plants and pollen were very important for bees to evolve. But if it hadn’t been for new behavioural traits that allowed to keep the pollen safe from spoilage through water and fungi, the megachilid bees would probably never have been able to leave the deserts.
The cell linings they produce can vary widely. Some bees use mud or chewed leaf paste, others coat the nest with cut out pieces of leaf, and some cement together little pieces of gravel. Whatever the material, all these linings seem to have water-repellent and anti-microbial properties.

Photography: Neil Bromhall

There also are a few megachilid species that never got into cell-lining at all.
But they are still in the deserts.

.
Litman JR, Danforth BN, Eardley CD, & Praz CJ (2011). Why do leafcutter bees cut leaves? New insights into the early evolution of bees. Proceedings. Biological sciences / The Royal Society PMID: 21490010

Pollination is probably the most stressful time for any almond grower in the Central Valley (I talked about their Breathless Anxiety before).  No wonder that they are always looking for new ways to relieve pressure and to improve performance. Drugs, however, are not among them. But the white powder on the back of the truck in the picture is hardly any less sought after in certain circles at certain times of the year than the finest stardust in others.

These unadorned plastic bags hold a precious mix of fine sugar and high concentrations of almond pollen. Each bag is worth about a thousand dollars. During bloom, hundreds of pounds of this fertile white dust are blown into the air.

The idea is simple: by increasing the amount of pollen available in the orchard, the growers hope to increase the number of pollinated flowers, and with this the amount of almonds to harvest.
But blowing the pollen around won’t do. The grains still need to be delivered to the flowers by the bees. This is where the sugar comes in. It’s used as a carrier material for the pollen, but  it also gets very sticky when exposed to moisture, so it helps to keep the pollen in the trees. And the bees like it.
Plus, and here one really must admire the almond growers’ ingenuity when it comes to securing pollination: the powder gets electrostatically charged when it leaves the machine. So it better sticks to the bees. Who then dutifully rub it onto the flowers. Who then dutifully produce more almonds. At least in theory.

I don’t know how efficient this method really is. But given the cost and the effort that the growers put into this, one would assume that there must be some benefit to it. Something more than psychological.

They don’t look like much, do they?

But for a few weeks in February and early March, the lives of bees, trees and quite a few humans revolve around nothing but this: tiny grains of pollen, a few hundredths of millimetres in size, little more than a bit of yellow dust to the human eye.

This is almond pollen. It’s one of the plainer types (especially if compared to these), but that doesn’t stop it from being the currency of choice in an existential bargain.

A pollen grain is a germ cell that holds a complete single set of chromosomes. Pollen grains are generally referred to as male, because they are the smaller, mobile units of reproduction of the plant; its „sperm“ if you like (although, unlike in humans and many other animals, they don’t differ genetically from the females).

Every spring every almond tree produces large amounts of pollen, but all this pollen is of no use whatsoever for pollinating their own flowers. For almond trees depend on cross-pollination. They need pollen from another tree, and of a different variety, to reproduce. A complication, yes, but also a failsafe way to avoid inbreeding. But if it can’t use the pollen for its own flowers, why does the individual tree produce any pollen at all? Especially when the pollen has the same genetic setup as the female parts? Dispersal? There will be seeds to take care of that later. What else then? It seems that trees that produce lots of pollen have an advantage over their “lazy” neighbours. But how is it that their investment pays off?

Enter the bee.

Bees love pollen.

It’s their prime source of protein and never do they crave it more than in early spring. After a long and taxing winter, the adult bees are old and ragged and hell-bent on raising new sisters to replace them. Some of these sisters will, eventually, be swarming (and hence propagate a new generation), while others will work all summer to build sufficient stores to survive the following winter that will inevitably come.

For the old bees, at this time, nectar is a welcome bonus, but not essential (which is really good for almond trees, because they don’t have much to offer in terms of sweet juices, neither in quantity nor taste…). What the bees want is pollen.

So if it is spring and you have pollen, you can assume that bees will find you rather attractive.

That, of course, couldn’t be of less concern to the almond tree, if it weren’t for another twist in its own reproductive biology. Because not only does it need pollen from a different tree, it also needs it to be actively rubbed onto its pistils. Which is best done by an insect.

You can see where this is going.

If you are a tree, and you need bees to visit you in spring to assist with your very vital reproduction, it might help to produce something they want.

Like pollen.

Even if you can’t use it for yourself.

As long as it attracts bees and makes them crawl around on your flowers, it is well worth the effort. Because chances are that any given bee has been crawling around on another tree before you, rummaging around in its flowers, stuffing her pollen baskets and scattering the precious dust all over her hairy body; not caring the least for you or your reproduction, but so what? There she comes, loaded to the brim with pollen to rub onto your pistils, every single grain holding the potential of a new tree with within its striated walls. It’s all about give and take, right? And who knows, she might even carry some of your pollen into the world and onto yet another tree. Or she drags it back into her lair and has it baked into gluey yellow bee-cake. Which would be a terrible waste of your genetic potential, of course. But hey, you win some, you lose some. It’s almost as if the trees had planned it that way. Which, of course, they haven’t. It’s just that those that happened to do this were the ones more likely to leave descendants.

That’s how it is.

Or could be, anyway.

There might be a more prosaic answer to the question of why almond trees still “bother” to produce pollen.

Imagine a tree that is very productive when it comes to pollen. Chances are that this would lead to a spread of  the trait “high pollen productivity” in a population, simply because when you produce a lot of pollen you increase the probability of reproductive success. But maybe, with all that energy that goes into pollen production, these productive trees wouldn’t grow as old as others or would need more water or what have you, and so, over time, pollen production will settle down at some middle ground.

And conversely: Imagine “lazy” trees that have stopped producing pollen alltogether. They invest in flowers/pistils and try to catch every passing pollen they can. However, many of these pollen grains will come from “pollen-productive” trees. So there is a limit to how “lazy” a population will become. Unless all trees become “lazy” at the same time. Then there probably will be a point when there isn’t enough pollen around anymore and the population will die out.

It’s probably a bit of both. Those bees and trees have, after all, a long history of co-evolution. But one could go on speculating all day. If anybody knows of some proper research into these things, I would be delighted!

[post modified April 6, 2011]

Dear Readers,

Today, this little blog has been up for exactly one year.

Many of you have been following our forays into the bee world for quite a while now, and your numbers keep growing. This is great. Thank you!!

When I started this blog, I mainly wanted to share my ongoing wonder about the bees and their keepers and give you an idea of our process of filmmaking. I also saw it as a good way to stay in touch with all the people we meet in the course of the project and to connect with new people who may be interested in bees.

But how about you? After a year of writing for you, I realize that I know hardly anything about you. So I would like to ask: Who are you?

Tell me about you! What has brought you here? What are you doing? What’s your background? Are you a beekeeper? What do you find here that interests you? What else would you like to see?

Please, speak up! The comments are open. We are listening!

Liebe Leserinnen und Leser,

heute ist dieses Blog seit genau einem Jahr online!

Viele von euch folgen unseren Streifzügen in die Bienenwelt schon eine ganze Weile und eure Zahl steigt stetig. Das ist großartig! Vielen Dank.

Ich habe damals angefangen zu bloggen, um mit den Leuten in Kontakt zu bleiben, die uns im Laufe des Projekts begegnen, und um einen kleinen Einblick in die Entstehung des Films zu geben. Vor allem aber wollte ich die Faszination, die Bienen und Imker für mich haben, mit anderen teilen.

Aber was ist mit euch? Nach einem Jahr stelle ich fest, dass ich herzlich wenig über euch und eure Gründe weiß. Darum die Frage: Wer seid ihr eigentlich?

Erzählt mir von euch! Wie seid ihr hierher gekommen? Was macht ihr sonst im Leben? Was ist euer Hintergrund? Seid ihr alle Imker? Was findet ihr hier, das euch interessiert? Und was würdet ihr gerne noch sehen?

Wir hören!!

*With this, I join the who-are-you-thread initiated by Ed Yong and revived by Drugmonkey and many others in the science-blogosphere, from where a continuous flow of inspiration feeds into this blog.

Once out, those almond blossoms might look all picturesque and peaceful, but for those who are living off the almonds the predominant feeling is, in the words of one of our beekeepers, “breathless anxiety”.

Just before bloom, in late January, it is the first time that the beekeepers see their hives after winter; and after the massive losses of the past years, they have come to expect the worst with every load that arrives in California.
When too many of their colonies failed over winter, they will not be able to fulfill their contracts with the almond growers. Not only will they loose lots of money, they also will have to find replacements for their hives, and at this time of year, every other phonecall revolves around the question “Who has extra bees?”. They also have to keep a close eye on the progress of bloom, because the day bloom starts, all the bees have to be placed and ready to work in the orchards. No excuses.

For the almond growers, the situation is even worse.
Bloom is the time of year that decides about their entire crop. It’s now or never. Every flower that is not pollinated will never become a nut. So for the almond people it is not only important that the bees are there in time and strong, but that they are actually doing the job they get paid for. But bees only fly at temperatures above 13°C (55°F). And while the growers have some control over bees and beekeepers, the weather they control not. And this year, in late February, the weather had some pretty bad news:

Cold and wet is not nice for the bees and slows down the bloom, but you can always hope for better weather tomorrow. Frost, however, kills the flowers and can cause serious damage in the trees. So even if the weather is brilliant tomorrow, there is nothing there to pollinate. Frost means immediate and possibly permanent loss. And quickly. As much as 50% after 30 minutes (Dan Cummings).

Which is why the almond growers try everything to avoid frost damage.
Although water is an expensive good in the Central Valley, whenever the forecast is frost, they will crank up the irrigation and keep the soil as wet as they can, because as the relatively warm water cools it releases heat into the air. Only a few degrees, of course, but they can make all the difference.

In many areas they also send up helicopters at night to literally stir the air and to make sure that no cold pockets persist in the lower reaches of the more hilly orchards. This, too, is expensive, and not without risk for the pilots, because they have to fly low in uneven terrain at night. We heard of one whose searchlight failed in midflight. And the orchards are dark. No streetlights, no markings, just powerlines, hills and trees all over. Luckily, he found some workers who were out with their trucks. They guided him to an open field and made a ring with the trucklights so he could land. He made it safely to the ground just before he ran out of fuel.

By now, however, all battles are fought. Bloom is over, the crop is set, and the beekeepers are moving on to new pastures.

Like these really flavorsome (and a bit greasy) mint patties:

One of our beekeepers has begun to use these patties last fall to support his bees’ defence against Varroa and infections. Here, he applies them again before sending the bees into the almonds.
Overall, his bees came out of winter remarkably well, but this might be due to other factors as well.

The patties contain mint, lemongrass and other essential oils. It has been shown that lemongrass oil in high concentrations has antifungal and antiviral properties and contains a component (Geranial) that seems to confuse and disorient Varroa mites. Evidence for the efficacy of essential oils is still mostly anecdotal, but by now many beekeepers prefer them to chemicals. Although the bees can’t be very fond of the smell, it seems to be the lesser evil.

Sunday in the orchard…