Introducing the long horned bee

The bees!

So far in my blog posts I have focused on my research in weather and bee foraging, however another large chunk of my PhD is on solitary bees. In the UK we have 270 species of bee, something which most people aren't aware of. One of those is the mighty honey bee, which receives the majority of the media attention (I'm not bitter...). Then you have your bumblebees of which there are 25 different species and finally the rest are all what we call solitary bees. Everyone knows honey bees live in huge colonies, reaching up to a possible 60,000 individuals in one hive. Bumblebees too live in colonies, however these are much smaller, generally ranging from around 50-400 individuals, depending on the species. Honey bees and bumblebees make up our eusocial bees. As you might have guessed by the name solitary bee, they don't live in large colonies like the bumbles and honey bees, instead a single female will create a lovely home for her babies, lay her eggs, make sure they have enough food in the form of pollen, and then leave!

For my PhD I am only focusing on a few species of solitary bee and I'm using this post to introduce you to one of them.

Eucera longicornis

Or its common name, the long horned bee, if you look at the photo you can see why. The males have these crazy long antennae, which makes them very easy to identify, and look super cute.

So first off I will give you a little background info on E. longicornis and this will help you understand a little more about why I'm spending so much time studying it.

This little bee is actually fairly common throughout mainland Europe, however here in the UK it's in decline. It used to occur throughout Britain, both inland and along the coast, however now it only survives at a few dozen sites, most of which are on the south coast. This decline is thought to be due to habitat destruction and fragmentation, leading to loss of floral resources, aka their food.

Gatwick bees

Yes that is correct, Gatwick, as in Gatwick airport bees. Gatwick airport actually very kindly sponsor half of of my PhD, so if it weren't for them this blog wouldn't be here (take from that what you may...). So why are they so interested in bees? Other than the fact that bees are amazing, Gatwick is one of the few locations where this charismatic rare bee is still found. The fantastic Rachel Bicker, who works for the Gatwick biodiversity team, found the first aggregation of the bees back in spring 2014. With solitary bees, even though one female will occupy one nest, multiple females will all make their nests quite close together, in what we call an aggregation.

The plastic straws in this photo show where occupied nests are

What the above photo also shows you is the bank where this first aggregation decided to make their nests. What it doesn't show you is the huge thicket of bramble at the bottom of said bank, which during the course of my data collection I ended up having quite a personal relationship with.

The cool thing about aggregation 1 is that it's actually only about 200m away from the runway at Gatwick airport, which meant I got to be super fancy and fill out security checks AND I got to wear a high viz jacket whenever I was there.

The top of the bank where the bees are found, and the runway just beyond

Me lovin the high viz life

So what was I actually doing there, other than just running around in a high viz jacket with a butterfly net? I was determining the number of females present in the population and collecting pollen samples from the foraging females. The pollen collecting then allowed me to go back to the lab and determine what it is these bees are eating, without having to rely on the change encounter of seeing one actively foraging. I'll get back to pollen in a bit though. First I'll focus on the population stuff.

Capture, mark, release

If anyone reading this did biology at school, you have probably done this method of population estimation. It does what it says on the tin really, you have a fixed location which you sample for a fixed period of time, catching individuals within the population. When you catch one, you mark them, release them and then return the next day, or next week, or next month, and re-sample the population. If you re catch a marked individual you note it down and if you catch an unmarked individual, you mark them. You continue with this until the end of your data collection period and using a rather complicated mathematical formula, which I WON'T go into detail about, from your number of re-caught and newly caught individuals you can calculate the population!

So this is exactly what I did, thus the walking around next to the runway with a butterfly net for over a week. Now catching the bees was actually a little harder than I thought, and did result in quite a few trips down the bank into the bramble, but I persevered and did mange to get some top quality data, if I do say so myself. From my hard work I managed to estimate a population size and collected quite a few pollen samples, which is what I will cover next.

Pollen

Collecting pollen of foraging females is actually fairly easy. They carry it on the side of their back legs, and although it looks very similar to how honey bees carry pollen it's a little different as solitary bees don't posses pollen bags like honey bees, but this doesn't hinder them in anyway. I would catch a bee, mark her if she wasn't already marked (don't worry it's with non-toxic paint which after a couple of weeks fades away) and then using a high tech tool called a tooth pic, I would gently scrape away a small sample of pollen from one of her legs. This pollen was then taken back to the lab and by staining the pollen and examining it through a light microscope you can identify what species of plant it has come from.

On the right here is an example of some pollen (excuse the blurriness it's quite hard to get a photo through a microscope lens). This here is an example of some thistle pollen (not taken from Eucera) and I chose this one to show you because I think it looks a lot like what people think pollen should look like, with the spikes.

Now every plant species pollen will look a little bit different. In the case of Eucera the pollen I've collected all originates from the Vetch family. For example, meadow vetchling, birds foot trefoil, those kinds of plants. All lovely pretty wild flowers which you would find if you went for a walk in a wild flower meadow.

The fact they appear to only be foraging on this plants helps us understand why they are in such decline. In the UK since the end of the second world war we have lost an insane 97% of our wild flower meadows.

So the solution is fairly simple, right? Plant more wildflowers! Well to be fair to Gatwick that is what they have done. Through their biodiversity management schemes the area surrounding where these bees are nesting is brimming with wild flowers and long grass, an invertebrate heaven.

Although the population found here at Gatwick is small (up to about 50 females), I'm going to continue monitoring and see how their numbers do over the years. The fact that this inland population even exists I think is a credit to Gatwick and other organisations should take note.