What even are bees?

I’ve been writing this blog for a while now, and it’s occurred to me that I’ve never addressed quite a simple and a crucial question. What even are bees? Okay, okay it sounds a bit silly, but… what makes a bee a bee? Wasps are like bees, they buzz, they fly, they sting, but they’re not bees. Of course, you could argue this is just due to humans putting everything into variously labelled boxes. Nevertheless, asking what makes a bee a bee is an interesting question. For example, when you imagine a bee you might think about an insect that lives in a hive and produces honey, but for the vast majority of bee species (>90%) this simply isn’t true. So how would we define a bee?

Google gives you three definitions:

“1. a stinging winged insect which collects nectar and pollen, produces wax and honey, and lives in large communities.
2. an insect of a large group to which the honeybee belongs, including many solitary as well as social kinds.
3. a meeting for communal work or amusement.
“a sewing bee””

Not much help there (although I’m so up for a sewing bee). How about dictionary.com?

“Any hymenopterous insect of the superfamily Apoidea, including social and solitary species of several families, as the bumblebees,honeybees, etc.”

Okay… well I struggled to understand that one! Never mind, let’s start with the basics.

Bees are insects

First things first, bees are animals, specifically insects. But why? Biologists have a bunch of categories that we like to put everything into. These are defined by what characteristics the species has. We can safely put bees in the animal category as they can move and also are complex (made of multiple organs and cells). Simple, you’ve never seen many mobile plants after all. So let’s take a look at a bee. Well, they have 6 legs, antennae, compound eyes (essentially eyes that are made up of thousands of tiny eyes), jointed legs, a three part body plan (head, thorax, abdomen) and a chitinous exoskeleton – which makes them sound like an awesome robot, but actually just means they prefer to keep their skeleton on the outside and it’s made of a sugar compound, chitin. So they’re insects. Right, so that’s now narrowed it down to about 6-10 million species.

Within insects there is a group consisting of ants, wasps, sawflies and drumroll… bees. The Hymenoptera. These insects all have two sets of wings that are connected by little hooks called humuli. Some members of this group also has an interesting feature which is a tube-like egg-laying organ, the ovipositor. In many of the Hymenoptera the ovipositor has been converted to a stinger. Now we’re getting somewhere! Bees have stings! But this still doesn’t differentiate them from the rest of the group. 

Vegetarian wasps

Bees have been around for a really long time, around 130 million years, ~46 times longer than us! We know this because we have found ancient bees trapped in amber (just like in Jurassic park!) that look a lot like modern bees. Also this time-period coincides with an important new development for bees. Flowering plants. It’s probably difficult to imagine a world without flowers, but before 130 million years ago they simply didn’t exist. For a long time, plants had gotten by in their reproduction by just scattering their pollen to the wind and hoping that it would land on a receptive plant. As you can imagine this is a pretty inefficient system to reproduce, it’s the equivalent of going around and asking random strangers to have your babies. One person may say yes, but the chances are extremely low (and they’re probably insane). So in ~130 million BC evolution provided an alternative. Get insects to carry their pollen for them. To do this they had to become attractive, thus flowers!

Bees, comprising nearly 20,000 described species, and angiosperms [(flowering plants)], comprising over 250,000 described species, represent one of the most successful (and fascinating) coevolutionary partnerships on earth
— Danforth et al., 2012

Now the ancestors of bees are actually wasps. Specifically, their ancestors were Sphecidae wasps, which are wasps that stockpile corpses of insects. Yum. At some point some of these wasps started to stockpile pollen instead. You may think that some bee ancestors simply saw how pretty flowers were and became awash with love and peace and decided to forswear their previous murderous ways. You may be right. We simply don’t know. More likely it could be that they stockpiled insects that were covered in pollen, or by accidentally bringing back pollen as they went about catching insects. However it happened, this was the beginning of bees. Pollen, as it turned out, was a fantastic source of protein, perfect for juvenile growth and ovarian development, excellent things for passing on your genes! Any student of Darwin knows that passing on your genes is what it’s all about (nudge, nudge, wink, wink). To help with their new diet bees became hairier, this and their diet are about the only tangible differences between them and wasps. In the end bees are just vegetarian wasps.

Bees and agriculture: the best of friends, the worst of enemies

Now when you think about bees, I'm imagining one of the key things you'll think about, once you've finished checking if you have any honey, is their wonderful, industrious activity of pollination. Considering pollination in so important for many crops and can increase their quality, it would be easy to imagine that agriculture and bees are the best of friends. However this is far from the reality. Land use change and loss of flowering plants that bees like is consistently shown to be a key driver of bee declines. In other words, agriculture is at fault for much of the bee declines. This is unsurprising as farming is often the leading use of land, for example in the UK 71.3% of land is devoted to agriculture. Indeed, in the state of nature report by the RSPB they find that wildlife on farms has declined much more than anywhere else in the UK. So how does this opposition occur? Is there any way to help pollinators and help agriculture?

Do bees help crops?

The inside of a wild banana, complete with the seeds they once had! By Warut Roonguthai - Own work, CC BY-SA 3.0

The inside of a wild banana, complete with the seeds they once had!

By Warut Roonguthai - Own work, CC BY-SA 3.0

The first thing to recognise is that whilst a lot of crops do require insect pollination, a lot don't. Most of the staple crops we eat (wheat, rice, corn) don't require any pollination from bees as they are wind pollinated. Other crops don't even require pollination at all. Take bananas for instance, have you ever encountered one of the very tiny black pellets inside a banana? Well that's all that remains of what was once a seed. Hundreds of years of breeding have made bananas practically seedless, and we take offshoots to make clones of the banana trees we've already got.

With what crops remaining that do require insect pollination, only a small proportion of bees will actually pollinate them. Not all pollen is created equal (as many poor allergy sufferers will attest) and bees have their own unique preferences, even generalist species that pollinate lots of plants are picky about it. Therefore, and this may sound obvious, those bees that are common and do well in agricultural landscapes are those that pollinate crops. Bees that are rare, and so are the most vulnerable to declines, will not pollinate agricultural crops. This leaves us in a little bit of an awkward position, as when governments and charities argue the case for saving the bees they often state their usefulness to agriculture. This is not to say that bees aren't useful to agriculture, they definitely are, but many species do not benefit from agriculture and in turn they do not benefit from pollinator friendly practices put in place by farmers. The bees that do benefit are already reasonably common.

The question then becomes, do we protect only the bees that will have the greatest impact on farm yields and quality? - The most cost-effective strategy. Or do we try and conserve everything? - A hard sell, and would require a lot of land which we also need to produce food. 

I wouldn't want to be a farmer

The Wurzels in 2011... I couldn't get a decent image of a farmer...

By Maybesometime - Own work, CC BY-SA 3.0

I think it's safe to say that farming is a pretty tough gig. The industry has been in a long-term decline with incomes dropping and smaller farmers being pushed out by the larger wealthier farmers that are able to achieve economies of scale, diversify and obtain more subsidies. It says a lot for the industry as well that most of the people in it are fairly old, many 65+. Moreover, with an open market on most agricultural produce, if someone anywhere in the world can grow something more cheaply than you can, then you're directly competing with them. This pushes down food prices. Great for the consumer, none-too-great for the farmer.

With this in mind, it's hard to imagine that for many farmers biodiversity or bee populations are a priority. Indeed, farmers have many different pressures on the use of their land, as I said to make ends meet many are diversifying, doing things like putting aside their land for wind-turbines or using their farms as wedding venues. The European Union (EU) does give subsidies to farmers that put aside 7% of their land for promoting wildlife, including bees (see my previous post). However how the farmers achieve this is pretty much up to them, there's a list of different activities they can choose from in order to qualify for the subsidy, ranging from leaving the field fallow (not planted with crops) to restoring hedgerows. They are under no compulsion to make this bee friendly, although many choose to due to the benefits of pollinators. With the UK's exit from the EU though these subsidies may be at risk (then again who actually knows at this point?!), and I can hardly imagine them continuing such schemes without financial backing. Imagine if your boss asked you to devote 7% of your time to work and then not pay you for it, doesn't sound fair does it?

The reality is that what we actually spend on food does not really take into account the full cost of food production, the environmental cost as well as the monetary. So with increasing pressure on farmers to produce food, despite having declining incomes, is it fair to ask more of them? 

Farming is a tough gig, and many of the pro-bee practices only benefit bees that are already common to agricultural landscapes, how then can we come to an compromise between these two competing factions that seem like they should be the best of buddies?

The best of buddies

Children photographed in their natural environment who are probably friends

By Squelle - Own work, CC BY-SA 3.0

Whilst I've made a point of the fact that many bees do not contribute to pollination services, many many do. There's a reason honeybees are shipped across the USA in their droves to provide pollination services, for many crops it's vital. Increasingly it's being shown that wild pollinators are contributing a lot more than originally thought to pollination services as well. So encouraging their use in agriculture will happen. The concern is that only those bees that are useful will be the ones conserved. It's hard enough to ask farmers to put aside land for bees that will help them, never mind those that won't. The thing is though, we don't know if certain bees disappearance would have a negative impact on agriculture - by promoting biodiversity overall we're essentially insuring ourselves against losses, as (hopefully) when one species declines another can take it's place. This has been well documented, in various species. It's hard to fully understand all the interactions that occur between species as well, it's often only when a species is gone that we can understand the implications its disappearance. Therefore, it makes good practical sense to ensure as many pollinator species as possible.

To resolve this with agriculture we need to appreciate that we cannot ask for this voluntarily, it needs to be backed up by governments. There will be benefits to yields from pollination, however that's a tough sell until you see it first hand and, personally, I don't think I would take that risk if my livelihood depended on it. Besides, to attempt to conserve as many species as possible may require practices that do not have direct impacts on pollination. More research (funny that I might think that...) on how best to increase bee diversity without compromising on yields (or perhaps increasing them! There's some interesting research...), would be of benefit, especially as we are increasingly aware that it's not all about the honeybee. Also we need to slow-down land use change in the tropics and consider making more reserves in the developed world where farmers have left.

In the end though, perhaps we need a little bit of unpragmatism. Just being solely utilitarian about this, i.e. 'how will this benefit us?', may be short-sighted. We have to consider what sort of world we want to live in. We likely could develop a system that engendered huge farm yields from relatively few pollinators, but then what about those pollinators that disappeared? Those we didn't even get to know before they vanished. What about the plants that depended upon them? They would disappear too. We could live in a world that functioned brilliantly for humans, however we may become paupers of beauty, nature and the soul.

Thanks for reading, I hope you enjoyed! Don't forget to subscribe below as it really helps me out :) Comment as well and I will get back to you! You can also subscribe on bloglovin' and follow me on twitter if you do that sort of thing.

Nick

Beerexit

In the wake of probably one of the most important referendums my fair nation of the UK has ever had, the EU referendum, I couldn't help thinking I ought to cash in jump on the bandwagon write an interesting article. So with that in mind rather than dealing with some of the more frivolous questions like 'What will this mean for the economy?' or 'Who will lead the country?', I'm going to try and decipher what it is the European Union does for bees and will leaving the EU mean bad news for bees. With 1 in 10 bees in Europe threatened with extinction and many crops reliant on them for pollination, this may be critical.

What will this look like in a few years?

By Kolja21 - Own work, CC BY-SA 3.0, 

The European Union of beekeepers

In the EU there are 630,000 beekeepers, with over 16 million hives, producing about 234,000 tonnes of honey. This is not even to mention the pollination services that are provided as part and parcel of beekeeping. These guys are surely valuable to the EU? Well Brussels certainly thinks so, mandating that every member state should implement a national apicultural (that's beekeeping to you and me) programme, what's more is they're willing to foot the bill by offering 50% back for whatever the member state spends on it.

So what do these national apiculture programmes actually do? There's 5 main areas:

  • Technical assistance - EU offers training to enhance efficiency and marketing of beekeeping
  • Control of varroasis - The varroa mite has been devastating hives across Europe and so the EU is contributing financially to promote use of approved products to deal with it
  • Assistance with movement of hives - The EU has created registers and maps, and also provided equipment to allow the easy movement of hives to ensure there are always flowers available for the bees
  • Restocking assistance - To compensate for bee losses the EU is funding activities to promote queen production and the purchase of bee colonies
  • Applied research - Research to help promote bee health and quality honey production amongst other things

So there's quite a lot of assistance for beekeepers, but recent research (again by the EU...) has shown that honey bees are not the main providers of pollination in Europe, so what else does the EU do for bees? 

Research, research, research

The EU is a big funder of research and with such alarming declines in bee numbers over the past few decades this means they fund a lot of bee research. If you want an example then look no further than my opening paragraph, the study finding that 1 in 10 bees in Europe are declining was funded by the EU. The union has also formed the LIFE - financial instrument for the environment. The LIFE has a €3.4 billion budget and is committed to support environmental, nature conservation and climate change action; bees fall well into the LIFE's categories so many research projects are funded by the LIFE.

I'm all about the moving images today, and nothing ever looks more sciencey than the double helix of DNA.

By brian0918™ - Own work, Public Domain, 

Here are some examples of cool EU bee research projects:

  • Smartbees - Identifies resistance genes for Varroa and other viruses and gets them into bees via breeding, making healthier bees!
  • Super-B - A research project bringing together scientific and social communities involved in conservation and sustainable management of ecosystem services to help promote sustainable pollination throughout Europe.
  • ALARM - Project to quantify bee (and other biodiversity) losses and to understand causes
  • STEP - Specifically tracking trends of pollinators and assessing the impacts of these trends on agriculture
  • BEE-DOC - Network of 11 institutions to improve colony health

And many, many others...

The common agricultural policy (CAP)

CAP is the EU's agricultural policy, which looks at farmer subsidies and rural devlopment among other things. This is one of the main things that the EU spends it's money on, it's around about 39% of the EU's budget (as of 2013, although that's down from 71% back in 1962), and you may be familiar with it as it's often one of the key things that brexiteers chastised the EU for. With such a massive organisation covering a huge area, it's bound to have many problems, but what about the bees?!

CAP, in part, provides farmer subsidies and more recently these have been focused on paying farmers to put aside land to create ecological focus areas (EFAs) to help wildlife, which is EU mumbo-jumbo for "plant some flowers and other plants and we'll give you some money". Which is exactly what has been happening. Around 7% of land has to be put aside for these EFAs in order to qualify for the subsidy, as a result these schemes have been attributed to the return of several rare bumblebees. In addition in a statement from David Nussbaum (chief executive of WWF-UK, that's the non-wrestling one) and Mike Clark (chief executive of the RSPB) they say that the EU holding the UK to account has ended it's reputation as the dirty man of Europe with schemes such as CAP.

Neonicotinoids... again

As those familiar to my blog will know, the EU banned 3 neonicotinoid pesticides due to negative effects on bees, for more info check out my previous blog. The UK actually voted against this measure and so we can say with some certainty that if it wasn't for the EU then the ban would not be in place in the UK. Whilst there's still a debate surrounding these pesticides, there is a growing body of evidence that they are causing negative effects on bees. So let's put this one in the plus for the EU side... for the time being.

A picture of the queen, because UK?

By NASA/Bill Ingalls  

But the UK does stuff for bees, right?

Of course, all that I've said so far does not exclude the UK from caring for our little buzzy friends and indeed the UK has developed a national pollinator strategy, which is the UK's action on bees. 

One of the first parts of the strategy is to help promote wildlife for pollinators on farms using CAP the EU's... oh... awkward. Indeed in looking through the document it seems that many parts of the strategy are reliant on CAP, charities or on voluntary measures. Voluntary measures are fine and all, but let's be fair to farmers it's a tough gig and if they put 7% of their land aside voluntarily rather than for subsidies well... Reliance on charities is fair enough I guess, many of these receive funds from the government anyway, but their contributions can only ever be small.

There are some places where the government is putting it's money where it's mouth is. The government committed £350,000 over 3 years to encourage farmers to provide habitat for pollinators. They also helped establish several Nature Improvements Areas, although funding for these stopped in 2015... (they did find alternatives thankfully!). £500,000 was also spent by the government in improving the research base.

So there are definitely some things that the UK has put in place, although it did need quite a bit of encouragement from the public and environmental charities.

Now we're out...?

In the end it's clear that the EU has put a lot in place to help out bees, that's not to say that the UK will not pick up the shortfall. The government has seemed willing to fund many efforts to support bees, although these seem to pale in comparison to EU efforts. Without accountability to the EU the UK will need extra pressure from the public and environmental charities to keep up the good work, if the ban on neonicotinoids has shown us anything it's that the UK may have other priorities other than the welfare of bees. That's not to say that there weren't many good reasons for this action, just food for thought. Only time will tell what the environmental impact will be of the UK's decision to leave the European Union. 

Why do people want to save bees?

This may sound like a bit of an odd question for a blog such as my own, however the question is less why do people want to save bees, but why bees in particular? With so many animals endangered and struggling to hold on, why do bees get special precedence in our minds?

Worker bees

One of the most common phrases that gets thrown around in lazy late-summer picnics is "What is the point of wasps?". While I'd be quick to point out that wasps are actually pretty good pollinators and are absolutely vital for keeping the population of many other insects down (see my colleague's blog on this!), the fact is nobody ever asks "What's the point of bees?". Even when people get stung, bees are only defending themselves. Wasps get no such defence. But why is this? Well the point could be for many people are aware that bees are pollinators. Most people are aware of the fact that bees are helping us out, by working hard and pollinating our crops and other plants that we enjoy.

Indeed science backs these thoughts up, and bees have been estimated to be worth billions and billions of dollars. Of course any estimates of what bees are worth are based on a lot of guesswork, but it's pretty obvious to see that they are worth a lot of money to agriculture; you only have to look to cases in China, where they have to pollinate crops by hand due to lack of bees, to see why. Going around with a paintbrush and a step ladder (seriously) laboriously moving pollen from one flower to another is time consuming and very expensive. So we can see a clear and real benefit of bees, therefore we should seek to conserve them, right?

This type of argument for conservation due to economic sensibleness is called the 'Ecosystem Service' argument. Literally the ecosystem is providing us a service, so let's keep it around hey? I mean do you have $153 billion a year to pay for pollination? Didn't think so... This argument has been around for a couple for decades now and has found popularity with scientists and governments, as it just seems to make sense, doesn't it? We need the environment so we should conserve it. However, as I said, this argument has been around for a couple of decades now and we're still seeing declines of many species, including bees. The trouble with assigning economic value to species is then we are deciding which ones are important, i.e. are species only important if they're valuable? Indeed Kleijn and colleagues (2015) argue that as crop pollination is only provided by a small subset of all bee species then most do not benefit from ecosystem service based approaches.

So maybe this is a factor, certainly for important crop pollinators like honey and bumblebees, but people seem interested in the decline of all bee species. There must be a little more to it.

A red-tailed bumblebee (Bombus lapidarius) I snapped just outside the University of Birmingham

A red-tailed bumblebee (Bombus lapidarius) I snapped just outside the University of Birmingham

I like you, you're cute

Another reason for our desire to keep our bee brethren around is that they're cute. Okay, I may get some argument here, but when their competition in the insect world are insects with such marvellous names such as stinkbugs, slugs (actually a mollusc, but just for the sake of argument) and flesh flies, then they're doing pretty well. I mean can you think of a cuter insect?

Cicadetta montana the only British species of Cicada that hasn't been spotted in the wild for 15 years.

By Honza Beran - Own work, CC BY 3.0 

In terms of conservation you see this all the time, charismatic animals are the poster children for conservation. There's a reason the WWF's logo is a panda and not the even more endangered Catarina pupfish (a rather dull looking fish about 4cm in length). When you see campaigns for conservation they use emotive images of lions, not June beetles. And this could be why we're interested in saving bees and why you probably haven't heard of the far less attractive endangered British cicada (Cicadetta montana). But what makes them cute?

Well scientists being scientists there is a supposed formula for cuteness. In 1943, Konrad Lorenz postulated that it would be evolutionary advantageous to think that babies are cute, so we wouldn't abandon them by the roadside or just lose interest in them. After all they are a big commitment and drain on our time, I guess we ought to get something out of it... Therefore, infant-like characteristics such as large eyes, big heads, chubby cheeks and a protruding forehead, small noses, plumpness, and short and thick extremities should be considered cute. And indeed this seems to be backed up by several studies. Glocker and colleagues 2009 showed pictures of altered babies (to have more or less features that Lorenz describes) to undergraduate students and asked them to rate how cute they were and their motivation to take care of them; the students indeed rated babies with more of Lorenz's characteristics as cuter and their motivation to take care of them was higher.

"Plz don't abandon me" - Baby

By Avsar Aras - Own work, CC BY-SA 4.0

This idea seems to hold true in animals as well. In 2013 Lehmann and colleagues published a study that showed that cuteness of animals was correlated to cuteness of human infants, thanks largely to the same characteristics that Lorenz pointed out. Indeed, when you look at a tiger cub, for instance, you see it's big eyes and head and you just go all squiggly inside.

For bees then these attributes hold a little, if you look at what are likely the cuteness types of bees, the bumblebees, you certainly can see their big eyes and chubby, cumbersome bodies and you may go awww. Although I think for many species how baby-like they appear is certainly debatable, but I would argue there is more to cuteness than simply a infantile appearance. For instance bumblebees are fluffy, and I don't think there's any denying this adds to the cuteness.

So is it that we simply think they are cute and are therefore interested in conserving them? Although it does seem a bit cruel when it's put in such blunt terms, perhaps this is a factor.

Bees facts

One key reason why we're so interested in saving bees could simply be that they are hugely fascinating animals (I'm biased I know, but I think this may change your mind). For example, honeybees survive winter by getting the bees to return to the hive and gather around the queen. Once gathered in a cluster they shiver, by the beating of their wings, to keep temperatures adequate for queen survival. This is why honeybees produce so much honey! They need a lot of energy to keep this up, so they store it as honey. Over a single winter a colony of honeybees can eat over 10kg of honey! 

Bees also have fascinating sex lives, just see my previous blog post. And in honeybees the queens can produce 1000s of eggs a day. Busy busy bee! Honeybee hives are also pretty much sterile, honey and propolis (bee glue essentially) have antibacterial qualities and bees actively clean out their hives. Honeybees can communicate by dance too. By doing the so-called waggle dance they can tell other foragers where plants are located, just see the video below!

Moving away from honeybees, bumblebees are very interesting too. For example, bumblebees have 'smelly feet', that is they have oils on they feet that can tell other bees that they have visited a flower. This prevents other bees from trying to get nectar from a flower that's already been ransacked! When summer ends and winter is on the horizon bumblebee queens will found a decent patch of soil and bury themselves about 10cm down. Once there they can survive temperatures as low as -19ºC.

Not leaving solitary bees out, these bees make up the vast majority of bee species and are usually the more specialised. There are many of these bees that can only pollinate one flower and this one plant is reliant on them for pollination. For example Rediviva intermixta a south African solitary bee has specially adapted forelegs to collect oil from a small number of plants, which it then uses in its nest construction. Solitary bees collect pollen for their offspring, they will collect enough for their young to reach adulthood and will more or less leave their brood to get on with things after that.

Maybe I am biased, but there are certainly some very interesting things about bees.

What is art?

"Art is the unceasing effort to compete with the beauty of flowers - and never succeeding"
- Marc Chagall, Russian-French Artist, 1977

In the end it's difficult to really try and work out why we we're so interested in bees. Perhaps they are like art, we value them for no rhyme or reason, we just do. In the book 'Wild Ones' by Jon Mooallem he makes the argument that we are interested in animals for how they exist in our imaginations. Nobody was interested in conserving the grizzly bear when it was a terror to our lives, but once it was reduced to rarity somehow it transformed in our imaginations to be a noble beast worthy of conservation. Maybe it's a combination of many things that is too complex for us to understand. After all why do we like anything? It boggles my mind why anybody would sit down and for several hours watch big sweaty men crash into one another chasing a sphere, but people do, for some it's a religion. 

We have been partners with bees for over 9000 years, and they're certainly worth saving. The dynamics of honeybee colonies are constantly fascinating to many, they provide us with wonderful services (if you like eating then thank the bees) and they are, in my opinion and that of others, very cute. Perhaps it's best not to dwell on why we think they are worth saving, but it's enough to say that we do, and we can hopefully use this interest to get people to appreciate more of the natural world and the plight of many species in it.

Should Vegans Eat Honey? and other questions

Oftentimes when you're out and about being a bee scientist, the topic of your job comes up and people are fascinated. Bees really capture people's imaginations, and one of the side-effects of imprisoned imaginations is that you get asked all sorts of weird and wonderful questions. Here are a selection of a few that I thought I'd tackle today.

So, should vegans eat honey?

So first of all I'll just say that as far as I'm concerned you can eat whatever you like, your diet affects me as much as mine affects you - not at all - but this is quite a common question so I'll have a go at answering it.

The first point I'd like to make is that according to Potts and colleagues (2010) due to the impact of Varroa destructor (a horrible parasitic mite that has devastated honeybees) wild honeybees are essentially non-existent in Europe and the US, the only ones left are in the care of beekeepers. Beekeeping as a industry has been in decline for decades, so the number of these safeguarders are, as well, diminishing. Therefore buying honey can help this struggling industry, especially if you're buying directly from local producers, and without this industry well... we won't really have any honeybees.

As a big buyer of bee pollen (unsurprisingly my bees love it), I've noticed that it is often advertised as a superfood, not only that but a vegan superfood. This confused me as, as far as I was aware, many vegans don't eat honey, so why then is this okay? It actually turns out that this is a big area of controversy in the vegan community, as bee pollen is a plant product. Bee pollen is rolled up pellets of pollen and bee spit (yum!) that is collected and stored by bees it is high in protein and vitamins, and as the main part of it is coming from the plant then that means that's okay (at least according to some vegans). The problem with honey, on the other hand, is it's actually a animal 'product', i.e. the animal has actually made it itself. People also feel uncomfortable with taking away the bees' hard earned stores, in researching this I often came across very emotive articles about how hard bees work and one particularly inciteful post described the enslavement of bees. 

Inflammatory writings aside the idea to not take anything that may cause an animal harm, suffering, or which can be likened to speciesism (if I'm understanding vegan philosophy adequately) is perhaps a noble one, but it falls down a bit for bees. Bees should certainly be considered animals, but if you're unwilling to eat anything that has been produced by their labour or by them, I've got bad news for you, you might well starve. What I'm saying is we are hugely reliant on bees for pollination of crops, not just for increasing the amount (which they do incredibly effectively), but also for quality. As a result bees are used across the world to help our crops out, and this is not even to mention the wild bees (and other insects) who also tirelessly pollinate our crops for free. So if you don't want to use anything that has had animal labour then I hope you like bread and corn (these are both from wind pollinated plants).

In terms of the actual honey as well, good beekeepers (sorry Bill) will only take the excess honey produced. Honeybees produce a hell of a lot of honey to be stored and they don't actually need all of it, especially if they've got a good beekeeper looking out for them, so taking some of their honey doesn't really have any negative effects on them.

So in my opinion perhaps we should all eat a bit more honey (especially local stuff!), as not eating it will likely do the bees more harm than eating it, and I wouldn't worry too much about their enslavement, I can assure you if there had never been any humans bees would still be doing the same thing, they need to do it to survive and they enable us to better grow so many crops and plants too, I don't know what we'd do if we didn't let them help us out.

Can honey cure my hay-fever?

This is an odd little one that remarks of an old wives tale, but appears to be backed up by some amount of science. So as far as I'm aware the thinking behind this goes that pollen causes people's allergies, i.e. hay-fever, so if you ingest it (e.g. if you eat some honey) then you can build up your tolerance to the pollen: a process called immunotherapy. In peanut allergies this has actually shown some promise, so will honey do the same?

The short answer is no. I only managed to find one study by Rajan and colleagues (2002) and they found when they gave volunteers a placebo (a cornsyrup mixture), normal honey (a blend) and some local honey there was no effect on volunteers hay-fever symptoms. That being said there is very little investigation into this, so it's not beyond possibility that it may work, but it seems unlikely.

In the end though eating local honey to allay your allergic hay-fever symptoms won't really do you any harm, unless ironically you have an allergy to honey, and maybe do the bees and the beekeeping industry some good, so it can't hurt to try!

Will bees die if they sting you?

Yes and no. So some species of honeybees have barbed stingers. This means that if they sting something with a sufficiently thick skin (like, oh I don't know... a large hairless bipedal mammal) their stinger will become stuck and when they try and pull it out it will actually end up pulling out all sorts of vital bits and bobs from their abdomen, resulting in death. They can, however, sting other smaller creatures like insects many times without such issues. Most bees on the other hand have smooth stingers, so they can pull them out of you without any issue. 

I would just advise not getting stung though, leave their nests alone and try not to poke and prod them too much and you'll usually be fine.

Did Scientists really work out that bumblebees cannot fly?

"Aerodynamically, the bumblebee shouldn't be able to fly, but the bumblebee doesn't know this so it goes on flying anyway."
Mary Kay Ash

As much as I'm sure American beauty entrepreneurs know about aerodynamics of insect flight this one is pretty much bogus, but like many great stories it has persisted and is often used as an inspirational sentiment. Clearly bumblebees are aerodynamically capable of flight, their ability to do so would hopefully be all the evidence one would need, so how did this one get started? 

In short we don't really know the origin of this, but one of the best theories is that the French entomologist August Magnan in his book Le vol des insectes (Insect flight) that aerodynamically all insects, not just bumblebees, cannot fly according to some rudimentary maths. What was likely supposed to be some kind of flippant comment has endured, that does not mean to say though how bumblebees actually fly isn't really interesting.

Unlike airplanes that have stiff wings bumblebees have flexible wings and they use this to their advantage. The flexible wings allow the bumblebees to rotate them as they flap which creates pockets of low pressure, which also leads to small eddies (counter-currents) which in turn creates lift! The slow motion video below shows a common eastern bumblebee queen flying and you can see the flexing of the wings (skip ahead to 44 secs in).

This method of flying is actually really efficient as it creates very little drag, indeed scientists are actually looking at it to inspire designs for flying robots!

 

I hope you enjoyed my answers to some of these questions and I'll be sure to post about some of the more entertaining or interesting questions people ask me over the next few years. You can now also subscribe to my blog on bloglovin and I'm working on an email list. Until next time!


Neonicotinoids: What's the issue?

Neonicotinoids, a hard word to say and yet it’s been the unfortunate job of many a news reporter to attempt pronunciation in the past few years, but why has this been all over the media? If you’ve followed some of these stories you may be aware of the fact that these pesticides have banned in Europe following some evidence that they have harmful effects on bees. What exactly does that mean though? And how are they causing damage to bees?

What even are neonicotinoids?

A simplified diagram of a synapse

Neonicotinoids or Neonics (as the cool kids call them) are nicotinic acetylcholine receptor agonists, but what on earth does that mean? Well to find out we’ll have to take a crash course in synaptic transmission. So to send information throughout your body (and across the body of other animals) you pass it through nerves. Nerves are made up of a type of cell called neurons, and these pass this information in the form of action potentials along their long bodies. Now when the action potential reaches the end of a neuron there’s a gap between it and the next one. This is called a synapse. To pass information across this gap small molecules called neurotransmitters are used. These pass across the gap and they bind to receptors on the other side. Once enough of these molecules have bound the receptors the action potential builds up and the information continues to pass along the next neuron. This is a huge simplification, but it hopefully gives you some idea of how this process works.

But what does this have to do with Neonicotinoids? Well as I said they’re nicotinic acetylcholine receptor agonists. Nicotinic acetylcholine receptors are some of these receptors I’ve just mentioned, and the agonist part just means that they activate these receptors. They not only activate these receptors, but in insects they will bind to them very very strongly, meaning that these receptors are blocked which can lead to paralysis and death.

This sounds pretty bad, but Neonicotinoids are very specific about this binding though. Despite the fact that most animals (including us) have these receptors, neonicotinoids bind very strongly to insect receptors specifically, indeed they are one of the least toxic insecticides to mammals. Comparatively, in insects, neonicotinoids can be lethal at tiny doses. Neonicotinoids also have other positives, they are systemic, which means they are taken up by all parts of the plant. They can also be used as seed-dressings so you don’t have to spray them all over your field, nope, just apply a little at the seed stage (in fact you can buy them treated in this way) and then the whole plant is protected. It’s is useful features like this which have allowed neonicotinoids to gain almost a quarter of the market share of pesticides and be used for 80% of all seed-treatments (figures from 2008).

So what about bees?

With the recent declines in bee species (if you're unfamiliar check out the welcome page and my previous blog on bumblebees) scientists have been systematic in trying to understand what is causing the large scale reduction in bee numbers. One of the things that has been suggested are neonicotinoids. I mean after all, it says it in the name doesn't it? Insect-icide. Makes you think it may kill insects... Furthermore, with the massive usage of these pesticides (especially on key forage crops like oil seed rape) and their systemic nature meaning that they will end up in nectar and pollen, it is possible that they are having an effect on bees. It's not quite that simple, however, as like all pesticides neonicotinoids have been tested for their lethality to non-target organisms. This includes bees. At the doses used in fields they are not lethal to bees. Case closed? Not quite.

It has become apparent that even though these pesticides are not killing bees directly, they are causing sublethal effects. What does this mean? Well, for example, in 2008 Yang and colleagues found that in honey bees concentrations as low of 50 parts per billion (ppb) of imidacloprid (a neonicotinoid) affected how bees forage causing their forage trips to be extended. In another case Aliouane and colleagues (2009) found that sublethal doses of thiamethoxam (another neonicotinoid) caused them to be unable to remember smells or reduced their ability to learn. These studies have been joined by many others to demonstrate that there are sublethal effects of these pesticides on bees. A meta-analysis (this is where a load of studies information are brought together and analysed as one) by James Cresswell in 2011 found that sublethal effects of imidacloprid would reduce performance of honeybees by 6-20% These sublethal effects as well can leave the bees more vulnerable to diseases and other pressures that are affecting them. Neonicotinoids have also been clearly shown to interact with other pesticides, this is possibly more realistic as bees will not be exposed to stressors in isolation, so their effects may be compounded in reality.

What's more is that neonicotinoids seem to persist for along time in soil and Bonmatin and colleagues (2005) found that in 65% of farmland soils they surveyed contained more than 1ppb imidacloprid (enough to cause sublethal effects according to some studies), even though some of these fields haven't been treated by the pesticides in years. It has also been suggested by Dave Goulson (2013) that due to the persistence in soil of neonicotinoids and it's possible that these pesticides are taken up by non-target plants; Goulson's theory has been backed up by David and colleagues (2016) who found contamination of wildflowers near oil seed rape with neonicotinoids amongst other compounds. This could possibly be another route for bee exposure. 

With increasing pressure from environmental charities, the public, and with a a fair amount of scientific evidence for sublethal effects; in 2013 neonicotinoid usage was restricted in Europe. This did not come without some controversy however.

The controversy

Auseinandersetzung (the controversy) statues in Düsseldorf

By Собственное фото - Own work, Public Domain

The controversy has appeared as while no-one questions that there appear to be sublethal effects of neonicotinoids on bees, it is questionable whether the laboratory studies that show these effects are relevant to reality. Some studies have used concentrations much higher than those bees would actually experience, and what's more is that field studies have shown little evidence of population declines due to exposure to neonicotinoid treated fields. For example a review of the literature by Fairbrother and colleagues (2014) concluded that neonicotinoids were not a major risk for honeybee declines.

...under field conditions and exposure levels, similar effects [to lab treatments] on honeybee colonies have not been documented. It is not reasonable, therefore, to conclude that crop-applied pesticides in general, or neonicotinoids in particular, are a major risk factor for honeybee colonies, given the current approved uses and beekeeping practices
Fairbrother and colleagues, 2014

However, they did not rule out that neonicotinoids may interact with other stressors, which could in turn reduce bee colony survival. 

Furthermore farmers unions have not responded positively to the ban. The National Farmers Union (NFU) have claimed that without neonicotinoids the oil seed rape crop has been devastated. Pressure by the NFU, amongst others, has led to the UK government allowing emergency usage of neonicotinoids on certain farms.

So should we ban neonicotinoids?

With the ban and press surrounding it, there have been more and more studies of the effects of neonicotinoids. We must try to understand exactly what is going on here. Why do some studies (even field studies e.g. Whitehorn and colleagues, 2012) find that there are negative effect on bee colonies, whilst others do not (e.g. Stadler and colleagues, 2003)?

Recently Henry and colleagues (2015), have shown, as some have suggested, that you do not see the effects of neonicotinoids on bee colonies due to their ability to buffer the loss of bees by the queen producing more. Indeed this seems to back up the a study that shows that in solitary bees (that don't have queens) there is a reduction in the reproduction when exposed to field realistic doses of imidacloprid.

So it is possible that the observed effects in the lab are not then seen in field studies as the bees can buffer their populations. 

There are also big knowledge gaps, there are very few studies considering the effects of these pesticides on other bees than honeybees and bumblebees, not even to mention other pollinating insects. Additionally, outside of Europe and the US there are few studies indeed.

But should we ban them?

It's hard to say. The emphasis and the media surrounding neonicotinoids may actually be doing some of the pressures facing bee species a disservice. It's easy to ban a pesticide, it's much more difficult to change how we farm, how we use the land, it's also incredible difficult to control some of the diseases rampant in bee species. Are we focusing on neonicotinoids because it's easy? Other pesticides are used too, and it's possible that any pesticide will have sublethal effects. Indeed there are some studies that have investigated other pesticides and found that these have sublethal effects (e.g. Aliouane and colleagues (2009)). So are we just over-using pesticides?

There are many scientists who are proponents of something called integrated pest management (IPM). IPM is a method of pest control where pesticides are used as a last resort, pests are controlled through other techniques such as: using pheromone traps - pretend that the insects are going to 'get lucky' and trap them; rotational cropping - having different crops at different times so insects can't get used to it, trap crops - e.g. crops that attract insects and trap them in sticky substances, etc.. The idea is that if you control the pests through all other techniques you may not need to use pesticides and if you do you use them, you do it in a targeted manner.

Neonicotinoids are also far less lethal than many of their predecessors to other animals in the environment (including humans), using alternatives may not benefit other species. Should we only focus on pollinators and species 'useful' to us? 

There are also many pesticides in development that can target specific species. Perhaps we should focus on developing pesticides like these? But who knows how long this will take and if there will be unexpected consequences of using these pesticides.

In the end I will leave you to decide whether we should ban them or not. There certainly seem to be sub-lethal effects of neonicotinoids on bees, however we're still trying to work out the scope of this. We also don't know the effects for the vast majority of species. But what are our alternatives?

References/Further Reading

ALIOUANE, Y., EL HASSANI, A. K., GARY, V., ARMENGAUD, C., LAMBIN, M. & GAUTHIER, M. 2009. SUBCHRONIC EXPOSURE OF HONEYBEES TO SUBLETHAL DOSES OF PESTICIDES: EFFECTS ON BEHAVIOR. Environmental Toxicology and Chemistry, 28, 113-122.

BONMATIN, J., MOINEAU, I., CHARVET, R., COLIN, M., FLECHE, C. & BENGSCH, E. 2005. Behaviour of imidacloprid in fields. Toxicity for honey bees. Environmental Chemistry. Springer.

CRESSWELL, J. E. 2011. A meta-analysis of experiments testing the effects of a neonicotinoid insecticide (imidacloprid) on honey bees. Ecotoxicology, 20, 149-157.

CRESSWELL, J. E., DESNEUX, N. & VANENGELSDORP, D. 2012. Dietary traces of neonicotinoid pesticides as a cause of population declines in honey bees: an evaluation by Hill's epidemiological criteria. Pest Management Science, 68, 819-827.

DAVID, A., BOTIAS, C., ABDUL-SADA, A., NICHOLLS, E., ROTHERAY, E. L., HILL, E. M. & GOULSON, D. 2016. Widespread contamination of wildflower and bee-collected pollen with complex mixtures of neonicotinoids and fungicides commonly applied to crops. Environment International, 88, 169-178.

EHLER, L. E. 2006. Integrated pest management (IPM): definition, historical development and implementation, and the other IPM. Pest Management Science, 62, 787-789.

FAIRBROTHER, A., PURDY, J., ANDERSON, T. & FELL, R. 2014. Risks of neonicotinoid insecticides to honeybees. Environmental Toxicology and Chemistry, 33, 719-731.

GILL, R. J., RAMOS-RODRIGUEZ, O. & RAINE, N. E. 2012. Combined pesticide exposure severely affects individual- and colony-level traits in bees. Nature, 491, 105-U119.

GOULSON, D. 2013. REVIEW: An overview of the environmental risks posed by neonicotinoid insecticides. Journal of Applied Ecology, 50, 977-987.

HENRY, M., CERRUTTI, N., AUPINEL, P., DECOURTYE, A., GAYRARD, M., ODOUX, J.-F., PISSARD, A., RÜGER, C. & BRETAGNOLLE, V. 2015. Reconciling laboratory and field assessments of neonicotinoid toxicity to honeybees. Proceedings of the Royal Society of London B: Biological Sciences, 282.

JESCHKE, P., NAUEN, R., SCHINDLER, M. & ELBERT, A. 2011. Overview of the Status and Global Strategy for Neonicotinoids. Journal of Agricultural and Food Chemistry, 59, 2897-2908.

LUNDIN, O., RUNDLOF, M., SMITH, H. G., FRIES, I. & BOMMARCO, R. 2015. Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps. Plos One, 10.

SANCHEZ-BAYO, F. 2014. The trouble with neonicotinoids. Science, 346, 806-807.

SANDROCK, C., TANADINI, L. G., PETTIS, J. S., BIESMEIJER, J. C., POTTS, S. G. & NEUMANN, P. 2014. Sublethal neonicotinoid insecticide exposure reduces solitary bee reproductive success. Agricultural and Forest Entomology, 16, 119-128.

STADLER, T., MARTINEZ GINES, D. & BUTELER, M. 2003. Long-term toxicity assessment of imidacloprid to evaluate side effects on honey bees exposed to treated sunflower in Argentina. Bulletin of Insectology, 56,77-81.

WHITEHORN, P. R., O'CONNOR, S., WACKERS, F. L. & GOULSON, D. 2012. Neonicotinoid Pesticide Reduces Bumble Bee Colony Growth and Queen Production. Science, 336, 351-352.

YANG, E. C., CHUANG, Y. C., CHEN, Y. L. & CHANG, L. H. 2008. Abnormal Foraging Behavior Induced by Sublethal Dosage of Imidacloprid in the Honey Bee (Hymenoptera: Apidae). Journal of Economic Entomology, 101, 1743-1748.

Bumbledeaths: The plight of bumblebees

If you know anything about the declines of bees across the world (depending on when you check the news it's either completely impossible to miss or entirely likely you will miss it), you probably are aware that declines of honeybees are happening worldwide. You may also be aware of the struggle of bumblebees worldwide, but why are bumblebees declining? And why should we care?

Busy Busy bees

There are many reasons to worry about the loss of bumblebees and one of the most pragmatic is concerning food. If you like to eat, then having bumblebees around is very useful. In fact Klein and colleagues (2007) estimate that 35% of the crops we grow depend on pollinators (not even to mention wild plants!) these being mostly fruit crops. But what about all the other bees I hear you cry? Well as I've discussed before, all kinds of bees across the world are declining, so we cannot really rely on them either. Also bumblebees have a special trick up their sleeve. Buzz pollination.

Buzz pollination is a special technique for dislodging pollen from certain types of plants - and bumble bees are among the few species of bee capable of doing it.

This type of pollination is very efficient, it dislodges a lot of pollen, as the bees use their flight muscles to buzz, violently shaking the pollen out. Some plants are only able to pollinated by buzz pollination. Furthermore bumblebees are largely generalist species, which means they are not fussy about which plants they visit, which is a huge boon if you require a bit of pollination for diverse crops. Indeed Dave Goulson (2003) suggests that many crops may actually be limited by the amount of pollination they receive. So keeping around bumblebees means more food!

Another reason is that bumblebees don't just pollinate things we like to eat, no, they also pollinate a wide variety of wild plants, as I said they are generalist pollinators. What this means is that if these bees aren't around any more, there's a lot more plants that are going to be affected. Memmott and colleagues (2004) show that the more plants a bee pollinates the greater the risk of plants going extinct if the bees die out first. While these pollination networks are relatively stable (there are a lot of different pollinators to fill the gaps!), as I keep mentioning most bees are under pressure. Bumblebees as well represent a lot of diverse generalist species and these face very similar pressures, so if bumblebees disappeared a lot of plants would likely follow them.

What's more is that don't we have a moral right to protect species? After all the majority of the pressures associated with their losses are down to humans, as we'll discuss below. We should conserve species because it is the right thing to do, not just because they will benefit us. Anyway... aren't they just so cute too?

Bumblebee with pollen loaded in its pollen baskets

By I, Tony Wills, CC BY-SA 3.0

So... What's happening?

Bumblebees are under a lot of different pressures, these factors are likely combining together to make some pretty miserable bees. One key one is land use change.

Farming, farming, farming

What exactly do I mean by land use change? Well largely it's just that. The land is now being used for something different to what is was being used for before. The use of the land has changed. This mostly refers to agriculture.

One of the key parts of the world where we have the best indicators of how bumblebees are doing is my home, the UK. So let's look at the UK as a case study. In the UK it is clear to see that bumblebees have declined dramatically since the 1960s. What's changed? Well farming, farming has changed. During World War II the UK had found that if it hadn't been able to rely on producing enough food for itself once it was cut-off from global trade. To that end during the war there many campaigns to get everyone involved in growing food e.g. the 'Dig on for Victory Campaign'. Even with these campaigns without food supplies coming from the United States we likely would not have won the war. So after the war was over the government passed the 1947 Agriculture Act.

...shall have effect for the purpose of promoting and maintaining, by the provision of guaranteed prices and assured markets for the produce mentioned in the First Schedule to this Act, a stable and efficient agricultural industry capable of producing such part of the nation’s food and other agricultural produce as in the national interest it is desirable to produce in the United Kingdom
Excerpt from the 1947 Agriculture Act

This act, although written in governmental mumbo-jumbo, largely just puts in policy that the UK needed to produce more food and it would pay farmers to do so. But how was this achieved? Intensification of agriculture, which meant using more land for agriculture, using new techniques like chemicals and fertilisers to use the land more efficiently and the use of machinery, all subsidised. Indeed farmers were paid for producing excesses of food. It worked magnificently as well, at one point in the UK's history it was producing 90% of all the food it needed (currently it's more around 70%). Unfortunately... everything comes with a cost.

A monoculture of potatoes By NightThree, CC BY 2.0,

A monoculture of potatoes

By NightThree, CC BY 2.0,

The intensification of agriculture led to the loss of the ancient unimproved grasslands. These were meadows that were full of wild flowers that were chomped on by a few grazers (sheep, cattle and such) and as a result were havens for bumblebees. With the new technologies and varieties available farmers were able to produce incredible yields, utilising monocultures (all the same plant over a large area) to produce masses of uniform grass the could be used to feed huge herds of livestock, and could also be collected and made into silage (essentially wet fermented grass that could be stored and fed to animals). So the meadows with their flowers went... So followed the bumblebees.

A lot of land was also converted to agriculture as well, we lost marshes, we lost hedgerows, we lost many of the wilder parts of the UK and bumblebees (and many other animals) paid the price. The same is true in the US where huge regions (places the size of several counties of England) are just the preserve of a single crop.

Even for the land that was left as wild, in preserves, it was often fragmented; fragmented wild land meant that populations were separated from one another. When populations are separated it leads to a loss of genetic diversity, so populations are more closely related to one another. This is particularly true of bumblebees as they have a queen which is the only female that can mate and they usually only do that once. A good example of what happens to a species when they have high amounts of inbreeding, is probably the Habsburgs. The Habsburgs were a noble family in Europe who ended controlling most of it, however to maintain their grip on Europe they tended to er... keep things in the family (think Game of Thrones). The result is well... I'll let the picture of Charles II of Spain speak for that.

Charles II of Spain in his twenties. Note that this was a portrait of a royal... these were the most flattering portraits there were even supposed to be. Almost needless to say he had fragile health and did not live to see 40. 

By Luca Giordano - Unknown, Public Domain

Okay, so I may be being a little disingenuous here, but my point is that inbreeding is (most of the time) bad news. Bumblebees are no exception. The reduction in the variability between bees means that they are more vulnerable to random events, such as disease outbreaks or extreme weather. It also means that you can end up with sterile males. This is because the males, through inbreeding, can become diploid, so they have two sets of chromosomes (for a more in depth explanation see my previous blog post). For some bees this isn't an issue as they will eat any males that are diploid, but bumblebees are a little kinder and these males will reach maturity. Unfortunately sterile males lead to less baby bees.

Pesticides, not just for pests

Another major issue for bumblebees is the effect of pesticides. Before any pesticide is brought into general usage they go through rigorous testing to ensure that they have no limited (if not no) effects on non-target species. As bees are not targets of pesticides, indeed we would like them to pollinate our crops, pesticides are assessed for their effects on bees. However this falls down on two points. The first is that pesticides are typically tested for their effects on honeybees, which are not necessarily representative of all other bee species (would you trust a drug that had only bee tested on chimpanzees and not humans?), this includes bumblebees. So a pesticide may have no effect on honeybees, but a much different effect on bumblebees. 

The other issue with pesticide testing is that it is often only lethal effects that are detected in these trials. They don't often look at sub-lethal effects (although this is changing). So we may end up with a pesticide that doesn't kill bees, but causes effects on the bee that mean it is not able to function properly as a bee. For example Feltham and colleagues (2014) looked at what the effect of field-realistic doses of a common pesticide was on bumblebees. So a field-realistic dose meant that it was far below what is lethal for bumblebees, even so they found that the bumblebees brought back 31% less pollen per hour when they were exposed to this pesticide. This can lead to reduced queen production and also just less viable colonies. Queens are particularly susceptible to pesticides, as normally a population can rebound as queens can produce lots more offspring, but when a queen is first looking for a good place for a bumblebee nest, they are on their own. Therefore in early spring if queens are exposed to pesticides it may cause them to be unable to found nests.

The problem of pesticides is compounded as well, by the fact that pesticides can act together to compound their effects. In real-life environments bees will be likely be exposed to any number of different pesticides and other chemicals. Not to mention the fact that these sub-lethal effects can then also leave them more vulnerable to disease and other random events.

Bees for sale

In the US there have been catastrophic declines of bumblebees over a very short period of time. It's not entirely clear what has caused these declines, but one of the main culprits is Nosema bombi, a fungal infection of bumblebees that has a range of negative effects on their health. However the declines in the US have happened quite rapidly, so how has the fungus spread so quickly?

Commercial production of bumblebees is a possible reason for the quick spread of N. bombi. In the US bumblebees can be produced en masse, this is true for Bombus impatiens (the common eastern bumblebee) and Bombus occidentalis (the western bumblebee). This is fine and everything, lots of places need pollination (and I'm in no place to criticise commercial cultures) and these bees are usually produced for greenhouses, but sometimes when you have a lot of the same animal in a small space you can get build-ups of diseases (diseases spread very easily when they can move from one host to another). These diseases may not even affect the bees you are producing, but they may spread to wild populations. Whilst these bees are not supposed to ever leave the greenhouses, escapes do happen. Recently Cameron and colleagues (2016) tested this theory and they found that even though N. bombi was already present in the US, since these commercial operations had begun the amount of this disease had gone up markedly. This adds credit to the theory that commercial cultures of bumblebees have caused the incidence of this disease to increase.

Even if bumblebees are no longer kept in commercial cultures, this would not prevent the spread of disease. Honeybees are reared for commercial purposes on scales that near the ridiculous. For example a single farmer in the US can own billions of bees and millions of hives. Having this amount of bees together in one small space can increase the likelihood of the spread of disease. Honeybees can act, as well, as carriers for bumblebee diseases. The troubling thing about this is the diseases may not affect the honeybees at all, so you don't even know they are carrying it, but will still spread it to their bumblebrethren.

And of course... Climate Change

Now hopefully I don't have to tell you too much about climate change. As you're all probably aware increasing levels of certain gases (most commonly Carbon Dioxide is discussed) are collecting in the earth's atmosphere and causing the climate to change e.g. increased temperatures, climatic instability, extreme weather, decreased seasonality etc. But what does this mean for bumblebees?

2015 was the hottest year on record

By NASA Scientific Visualization Studio 

Well for one, it may allow different species and subspecies of bumblebees to invade other habitats. This doesn't sound too bad, as the bumblebees are just moving around, no? Well it can have some unfortunate consequences. For example Owen and colleagues (2015) assessed if a subspecies of the Bombus terrestris (the buff-tailed bumblebee) was able to invade the UK. They concluded that it was possible, and if so it could displace the native subspecies. Invasions like these could reduce the variability of bumblebees and some plants that are pollinated by these bees may be lost if we have fewer types of bumblebees. In alpine areas (mountainous) climate change may cause bumblebees to move further and further up the mountain in order to maintain the same temperature that they are used to. This could mean that the size of their habitat is reduced and this again can reduce the genetic variability and lead to fragmentation of their habitat.

What's more is that bumblebees have something called a facultative diapause. What this means is that if the temperature is low enough at the right time of year the bees will enter a dormant state to survive the winter, however if the temperature is not low enough at the right time of year (before winter) they will not enter this dormant state. This could mean that in winter there are active bumblebees. These bees will likely struggle to find food (plants often have different cues for winter, that are not dependent on temperature) and also, as has been the case in many UK winters, winter may be late. Leaving bumblebees, quite literally, out in the cold.

There's also the fact that climate change can cause mistiming between plants and bees. For example Kudo and Ida (2013) investigated the timing between flowering of a spring-time plant and bumblebee presence. Over 10-14 years they found that when spring came early (due to climate warming) flowering occurred earlier, but there were no bees. This mismatch can lead to food shortages for bumblebees and lack of pollination for plants, which in turn can lead to population declines of both.

Is there anything we can do?

All that information probably sounds a little bit morbid. It's important to note that some bumblebee species are doing okay at the moment, so it's not all bad news, but we cannot rely on this continuing. Especially considering that all the factors I've discussed are not happening in isolation, they are affecting the bees all at once. However there are actions we can take to prevent further declines. 

As land-use is a big issue in declines we can look to the big land users. Farmers. Now farming is not an easy gig, so simply telling a farmer that we need more bees so... can he just plant some more flowers and things? is not going to work. We need to create an environment where it is favourable for both parties. We have an head-start in that pollination is good for crops, but setting aside land for biodiversity is a big ask. We can promote this through subsidies, this is controlled by the government, so if we show the government we care about bees, then we can show them that subsidies to farmers for biodiversity is in the public interest. This does happen to an extent, but oftentimes these practices get a bit watered down. 

We can also look to invest in research that can identify practices that will increase pollination without impacting too much on yield of crops. We also need to make these solutions practical. It's very easy sometimes to come up with solutions that sound great on paper, but in reality are difficult to put into practice (in my opinion scientists can be very guilty of this). The large amount of grassland in the UK makes it a prime target for such research and we can often combine increases in pollination services with other services (e.g. carbon dioxide capture by plants). 

You personally can help bees out by planting wildflowers and other such plants that are great for pollination. In an environment that is increasingly full of monocultures, sub-urban and urban areas can often be hot-spots of plant diversity with thousands of different flowers available for bees to use in peoples gardens. Many garden centres and seed providers have cottoned onto this too and can provide with seeds that are 'Good for Pollinators' (click here for a good Royal Horticultural Society post about just that). You can also help out or donate with the bumblebee conservation trust. Doing something like joining a charity can have the double benefit of you personally helping out bumblebees and also giving these charities more power when they come to challenging to government to change in ways like above.

Don't forget as well that just having a lesser environmental impact can help out the bumblebees, things such as walking or cycling instead of driving, recycling etc. You know the drill.

So all hope is not lost, but we must act now.

References

BOWERS, J. 1985. British agricultural policy since the Second World War. The Agricultural History Review, 33, 66-76.

CAMERON, S. A., LIM, H. C., LOZIER, J. D., DUENNES, M. A. & THORP, R. 2016. Test of the invasive pathogen hypothesis of bumble bee decline in North America. Proceedings of the National Academy of Sciences.

CARVELL, C. 2002. Habitat use and conservation of bumblebees (Bombus spp.) under different grassland management regimes. Biological Conservation, 103, 33-49.

COLLA, S. R., OTTERSTATTER, M. C., GEGEAR, R. J. & THOMSON, J. D. 2006. Plight of the bumble bee: Pathogen spillover from commercial to wild populations. Biological Conservation, 129, 461-467.

GILL, R. J., RAMOS-RODRIGUEZ, O. & RAINE, N. E. 2012. Combined pesticide exposure severely affects individual- and colony-level traits in bees. Nature, 491, 105-U119.

GOULSON, D. 2003. Conserving wild bees for crop pollination. Journal of Food Agriculture & Environment, 1, 142-144.

GOULSON, D., LYE, G. C. & DARVILL, B. 2008. Decline and conservation of bumble bees. Annual Review of Entomology. Palo Alto: Annual Reviews.

KLEIN, A. M., VAISSIERE, B. E., CANE, J. H., STEFFAN-DEWENTER, I., CUNNINGHAM, S. A., KREMEN, C. & TSCHARNTKE, T. 2007. Importance of pollinators in changing landscapes for world crops.Proceedings of the Royal Society B-Biological Sciences, 274, 303-313.

KUDO, G. & IDA, T. Y. 2013. Early onset of spring increases the phenological mismatch between plants and pollinators. Ecology, 94, 2311-2320.

MEMMOTT, J., WASER, N. M. & PRICE, M. V. 2004. Tolerance of pollination networks to species extinctions. Proceedings of the Royal Society B-Biological Sciences, 271, 2605-2611.

OWEN, E. L., BALE, J. S. & HAYWARD, S. A. 2015. Establishment risk of the commercially imported bumblebee Bombus terrestris dalmatinus—can they survive UK winters? Apidologie, 1-10.

OWEN, E. L., BALE, J. S. & HAYWARD, S. A. L. 2013. Can Winter-Active Bumblebees Survive the Cold? Assessing the Cold Tolerance of Bombus terrestris audax and the Effects of Pollen Feeding. Plos One, 8.

PACKER, L. & OWEN, R. 2001. Population genetic aspects of pollinator decline. Conservation Ecology, 5, 36.

PLOQUIN, E. F., HERRERA, J. M. & OBESO, J. R. 2013. Bumblebee community homogenization after uphill shifts in montane areas of northern Spain. Oecologia, 173, 1649-1660.

The Sex Lives of Bees

This post was inevitable as one of the things I talk about when discussing bees with people that really captures their attention is, of course, sex. Whether this is due to our inherent fascination with the horizontal tango, or that these are interesting creatures that have compelling methods of mating; it is always a topic of great interest. So here I'll try and give you a good taste of the after-hours habits of our fuzzy friends.

Hymenopteran Sex Determination

If you weren't too scared off by that heading allow me first to explain how gender is determined in bee species. So bees are part of a group called Hymenoptera, this is a group composed of bees, ants, wasps and sawflies. Hymenoptera refers to the fact that these species have two sets of wings that are connected by a series of hooks. In this group sex is not determined how you would normally think. In humans, for example, we have special sex-determining chromosomes (chromosomes are collections of DNA and genes), if you have XY you're a male and if you have XX you're a female (there are of course variations on this, but for simplicity let's leave it at that). In Hymenoptera males only have one set of chromosomes, also known as haploidy. Females on the other hand have two sets of chromosomes, also known as diploidy. Now how this actually causes the difference in sex is a topic for another time, but for now just remember that females have two sets of chromosomes and males have one.

Simplified version of Hymenopteran sex determination. Where the lines represent chromosomes. So you can see that the females all have two chromosomes and the males only one. The female offspring get one set of chromosomes from the mother and one from the father. The males on the other hand only get one set of chromosomes from the mother.

Sex in Social Bees

As I've mentioned before there are different types of bees (social and solitary) and as such their sex lives differ greatly. Social bees are things like honeybees and bumblebees. In these species there is one fertile female known as the queen who produces all of the offspring. The rest of the females are the workers which are infertile, so they cannot mate. However as we discussed with the hymenopteran sex determination you don't need to mate to produce a male, so in some rare cases (~1 in 10,000) workers do produce males. Sometimes workers can even undergo a process called parthenogenesis (essentially cloning of oneself) and produce more female bees, but this is very rare.

Now you may be wondering what is it that allows the queens to produce all the offspring and the workers to (in most cases anyway) not be able to. The answer is quite simply food. You've probably heard of royal jelly. This is a substance produced by nursing worker bees that is given to the larvae, in workers this is only for the first couple of days, whilst for the developing queen they are given royal jelly throughout the entire larval stage. This extension of feeding allows the queens to become much larger and also allows their ovaries to develop.

Males, or drones, are just the haploid (one chromosome) version. They have longer developmental periods and exist for one thing. Mating.

Mating in Honeybees

So when a young virgin queen bee goes out to mate, she does so in flight. A virgin queen will fly around wafting her pheromones everywhere. This will attract lots of drones. Now honeybees are by no means monogamous.. so lot's of males is exactly what she wants. She will mate with several (~12-14) males in a flight. They will fly up and catch her and mate with her in the air, once they are done she pulls away and rips the endophallus (bee penis) out and leaves it attached in her (ouch...), this action rips the males abdomen and in most cases causes them to die. Once the female has mating with enough males she will store up the sperm and use this to fertilise eggs throughout her lifespan.

Mating in Bumblebees

A buff-tailed bumblebee Bombus terrestris

By Alvesgaspar - Own work, CC BY-SA 3.0

After that rather traumatic explanation of honeybee mating, let's calm down a bit with the far more civilised bumblebee.

[The bumblebee males] simply hang around, often in amicable groups, drinking nectar where it is available, and presumably attempting to mate with females whenever they appear.

- Professor Dave Goulson, A sting in the tale: My Adventures with Bumblebees, Chapter 12: The Birds and the Bees, pg. 141.

When it comes to bumblebees there is none of this flight and death as you see with honeybees. No bumblebees do it on the ground, in what can probably be described as a somewhat canine position... 

Male bumblebees are likely involved in trying to attract a mate, they fly around presumably wafting pheromones about in an attempt to attract a female. Some bumblebees do hang around outside nests waiting for females to emerge, such as tree bumblebees (Bombus hypnorum), but this is not the norm. Once a virgin queen has been attracted the male powerfully clasps the female around the head with his forelegs and stimulates... her... with his hindlegs. Once accepted (the female is much larger so if she's not interested she can just shove him off) mating lasts around half an hour (not bad!) and once completed to ensure monogamy the male secretes a mating plug into the queen to prevent other males... getting in.

Sex in Solitary Bees

As opposed to social bees, in solitary bees every female is fertile, they all build their own nest and provision all their young. This means that the males, again, only exist for one purpose. Mating. 

And this time there are a lot more females to choose from, as such males are typically not monogamous whereas typically females are. As a case study we will look at the red mason bee.

Sex in Red Mason Bees

So in my beloved Osmia bicornis the males emerge anywhere from a couple weeks to a few days before the females. So they tend to lie in wait for the females. The majority tend to wait outside of nests for females to emerge and others will patrol around floral resources, or just nearby the nests. The reason there are several different strategies is that females tend to get out of the nest quick sharp in search of food (in fact it has been observed that on emerging some females have died because they have been mobbed by males before being able to feed), so waiting by the nest may not guarantee sexytimes. 

The males, are a bit dim and will jump on anything remotely bee shaped (sometimes even things not remotely bee shaped like the paintbrush I use to move them...), although they will quickly realise which is which. The reason. Pheromones. Virgin females will pump out a lot of pheromones to attract a mate, if a male gets wind of these and mounts a female, it is on.

Once mounted a male will begin a little precopulatory display, this lasts around 10 minutes. The male will rub the females antennae with his own and use his forelegs to waft his pheromones over her. He will also vibrate his thorax for as long and as hard as he can. All these things allow the female to determine if the male is worth bother with. The female is much larger so she can simply push him off if it doesn't impress her much.

If accepted to male will mate with the female and like the bumblebee, fill her with a plug to prevent other males and he will also perform a post-copulatory display showing that this female has been mated with and the male will cover her with anti-aphrodisiac pheromones. The female herself will also reduce her own attractive pheromones, as now she is done with that business she can concentrate on the important nest building.

A little video I took of Red Mason Bees mating with me voicing over a little.

The less attractive pollinators

When you think about pollination I'm betting that what you're thinking of is a lazy summer day with a meadow filled with flowers of all types with a multitude of bees visiting these flowers to find food for their brood. I am going to wager that you very rarely include flies in this idyllic picture. You're not alone either, when pollination studies are conducted, biologists as well focus mainly on bee species (if not bees, then butterflies or hoverflies... you know all the pretty species). 

This is for good reason as well, bees are very efficient pollinators, they have specific structures for collecting and transporting pollen and use flower's nectar as a food source. However it's pretty common knowledge that bee species are declining. Also bees are part of a larger ecosystem and it would be foolish to consider them as the only pollinators (with a few other pretty species thrown in there). So do we need to consider other sets of pollinating species? One set of species that is often overlooked are flies, the non-syrphid Diptera (that is non-hover-flies).

A comparison of flies (non-syrphid Diptera) and hoverflies (Syrphid Diptera)

Photo on the left: By א (Aleph) - Own work, CC BY-SA 2.5

Photo on the right: By Thomas Bresson - Syrphidae sp.Uploaded by ComputerHotline, CC BY 2.0

The forgotten flies

In 2015 Orford and colleagues decided to look at whether flies are important in pollination. The got a set of 11 independent studies together creating a huge analysis of 520 pollinators and 261 plant species. With this they were able to quantify the number of pollen grains collected per species i.e. their pollen loads. What they found was that bees had the highest pollen loads. No surprises there, we know bees are great pollinators. However they also found that fly species (non-syrphid Diptera) did not differ significantly in their pollen load from that of hover-flies (syrphid Diptera). They also found that these kind of flies are actually more abundant that their hovering-compatriots, so they may be able to provide more stable pollination services.

Blue-bottles, not just a pest

As a side project in my PhD I have been looking at a fly species for the reasons above, they're pretty good pollinators. The fly species I have looked at is Calliphora vicina, the blue-bottle. Now these are flies you'll probably all be familiar with as huge annoyances (after culturing them for a while I'd be tempted to agree...). However they are really good pollinators.

For example in 2007 Clement and colleagues assessed blue-bottle's effectiveness at pollinating leeks. They tested different densities of flies in cages and assessed blue-bottle's effectiveness in comparison to house-flies (Musca domestica) in cages. They found that as the density of flies increased so did the amount of pollination that had occurred and that blue-bottles were more effective than house-flies. Importantly as well they emphasised that these flies are very cheap compared to honey-bees and can be used as an alternative pollinator.

Also, in 2011 Brad Howlett looked at blue-bottles ability to pollinate carrots and directly compared this to honey-bees. He found that the seed yield of the carrots when pollinated by caged bluebottles was similar to that of honey-bees that were uncaged. When the flies were removed there was 10-fold less seed produced, so clearly they have an effect on seed number (this is indicative of pollination). When out in the open field the flies as well also spent a lot longer on the flowers compared to honey-bees (71 seconds versus 54.4 seconds) - furthermore they spent a lot longer than that when caged! Importantly he additionally found that honey-bees and these flies are active at different temperatures. Honey-bees were most prevalent at temperatures >25 degrees, whereas the flies were active at around 20 degrees. This means that these flies may be useful when conditions are not optimum for bees.

So next time you see a blue-bottle around, just consider it may be helping out some bees with pollination services. They may not be as pretty as other pollinators, but that does not mean we should overlook their usefulness. Hopefully in future when assessing pollination we will consider these forgotten fly species.

My PhBee

 

As it briefly states in my about me section, I'm doing a PhD at the moment on bees, so a little about it. I’m doing an iCASE (Industrial Cooperative Awards in Science & Technology) PhD funded by the BBSRC (Biotechnology and Biological Sciences Research council - scientist love acronyms...) at the University of Birmingham. So an iCASE PhD means I have an industrial partner who part-funds my PhD. In my case, my partner is Biobest. A really cool Belgian company who produce bumblebees for pollination services on a ridiculous scale - seriously I visited their facility and they produce millions of them, it's crazy! They’re now looking into other bee species, which is where I come in. They want me to investigate how to culture these bees.  

So why culture bees?

Bees are declining worldwide, this goes for managed bees as well as for wild populations. However there are still growing demands for pollination services, the population is increasing and we need food to feed everyone! We’ve been reliant on one species of bee for most pollination services for a very long time, so it makes sense to investigate the possibility of using other types of bee.

Additionally, commercially culturing a bee allows us better control over it’s environment so we can control pests and parasites. Currently for the bee I am investigating, the red mason bee, in commercial settings nests are put out into the wild and left to just to do their thing. There’s very little done to curb parasites, as the nests are often left in the same place year after year. These little bees have many parasites such as Monodontomerus obscurus a little parasitic wasp that lays it's eggs inside the bees cocoons allowing the larvae to eat the bees!

Monodomerus obscurus larvae inside a bee cocoon that have eaten a bee!

Monodomerus obscurus larvae inside a bee cocoon that have eaten a bee!

What’s more, as we can control the environment, we can attempt to control when the bees will be around. The bees diapause (I’ll come to this later) to overwinter, meaning there is the potential to manipulate this so we can have year-round pollination services.

Furthermore Hansted and colleagues (2015) investigated the usefulness of the red mason bee as pollinator in orchards and they found, amongst other things, that to actually establish a colony that will be there year after year there are costs associated with habitat management. It’s possible by rearing them commercially that we will be able to provide a more cost-effective service.

Why Red Mason bees?

Mason bee species generally have been investigated for their ability to pollinate. So for several reasons these bees are great pollinators. Firstly honeybees tend to get a bit confused and disorientated by greenhouse environments and when they get confused they tend to sting people. NOT GOOD. Mason bees have no such problems and have been used successfully in greenhouses.

Mason bees also tend to switch between rows of trees in orchard environments which is necessary for cross-pollination, whereas honeybees tend to go straight along a line.

Mason bee species also do not go far from their nests to forage so they will prefer the most abundant pollen source nearby, which is great when you’re considering monocultures (all the same plant in one place, as is common in farming).

One of the main things is that Mason bee species require a LOT of pollen, per bee they will collect about 3g of pollen over a lifespan which doesn’t sound like much but when you consider there are hundreds of these bees and how tiny the amount of pollen per flower there is, that’s a lot of flowers visited/pollinated. Also, they have really high stigma (the sexual part of the flower) contact with the flower while they’re busy collecting pollen (even more than honeybees!), which is vital for pollination.

“Given the pollinating efficiency of O. cornuta [the builder bee] on almond, 3 females per tree are considered sufficient to maximize pollination in an almond orchard.” – Bosch 1992

Culturing bees

So as I’ve said one of the main plans for my PhD is to tackle the idea of culturing these bees. Therefore, I need to work out what are their minimum requirements, not just to live, but also to reproduce. We want to establish a long-running culture, where we’re able to increase population numbers. So we want to know what sort of spatial requirements do they need? Noting that solitary bees are not used to living in such closed quarters as hives. What about temperature, food, water, relative humidity… all that fun stuff!

Keep looking at my blog posts to see how I’m doing!

Diapause?

Also, I briefly mentioned that the bees overwinter by diapausing. Diapause is a trait found in many insects that is an evolutionary adaptation to bridge unfavourable time periods, but not a direct response to this. This sounds complicated so I'll use an example. When winter (a time that is pretty unfavourable to most insects!) is approaching the day lengths get shorter, the insects take these shorter day lengths as a cue and begin preparations to enter diapause (kind of like when trees lose their leaves). In diapause they have increased tolerance to the cold.

Now red mason bees diapause obligatory, which means it's written into their life-cycle. Once they reach a certain life-stage they will enter diapause. In diapause they have a slower metabolism which means that they age much less quickly. This means that if we're able to alter their diapause we can possibly extend their lifespans and get bees out to pollinate throughout the year! This is another thing to be investigated in my PhD.

So I hope that gives you guys some idea of what I'm doing throughout my PhD.

Nick

P.S. All credit for the clever punnage in the title goes to Jake Ranson

Me hard at work with my pointless bee suit.

Me hard at work with my pointless bee suit.