Bumblebee Barf

When Bumblebee’s aren’t buzzing around, their working to procreate. In this segment, we discover why researchers at the University of California-Riverside are studying the unique way Bumblebees feed their future Queens.



When bumblebees aren't buzzing around, they're working to procreate.

In this segment, we discover why researchers at the University of California, Riverside are studying the unique way bumblebees feed their future queens.

Our partner, Science Friday, has the story.

In things that live in societies or have close social bonds, you have these situations where you're feeding from another individual, so in mammals, they're producing milk, but in the case of bees, bumblebees feed larvae by opening the wax envelope that the larvae are housed in.

You can see the abdomen contract and scrunch up, and you can actually see them then barf.

You have some individuals foregoing reproduction and instead helping give you food so that you can survive and grow, and there's something really special about that.

My name is Hollis Woodard.

I'm an assistant professor of entomology at UC Riverside, and my group works on bumblebee biology.

We're studying bumblebee behavior, physiology.

In particular, we're working on queen bumblebees, trying to understand how they're different from workers and some of the special challenges that they face.

They're basic questions about sort of the fundamental biology of bumblebees, but they're driven by this need to try to save them.

All queen bumblebees start life as an egg in a colony, so the eggs develop into larvae, and at some point in larval development, a female larva will develop into either a worker or a queen.

If she's a queen larva, she grows really large, and then she'll turn into a pupa.

That's when you can tell that it's a queen, and the queens themselves are much larger than the workers, and then she chews her way out of her pupal casing, her cocoon, and then when she's about a week old, she'll leave her colony, and she'll go off and mate, so these queens will find nesting spots, and they will excavate them, and they will lay eggs in them, and the reason why we're collecting them right now is, this is the only time you'll really see these queens flying around because, once they start their nest and they have workers emerge, the queens don't go out and forage anymore.

The workers do that for her, so the queens are out right now.

We can collect them, so it's this very special, like, window of time that we have right now.

So the species we're going to be collecting today, Bombus vosnesenskii, the yellow-faced bumblebee, they're really beautiful coloration.

We catch bumblebees with nets usually.

I hear one.

So we will go to patches of flowers where we think the bumblebees will want to visit, and we just wait for them.


I hear you.

[ Bees buzzing ] Typically, we'll swing a net, and then you have to swing it back and forth and sort of loop, flip the net over itself so you catch the bee.



And then we stick your hand into the net with a vial and try to catch them.

We caught one.


You're so big.

Hi, pretty.

Now that we have the queens in the lab, they will start laying eggs usually within a few weeks.

It's actually quite easy to keep a bumblebee in the lab, a queen, so you can put her in a pretty small box.

We give them all the food they could want, so we give them pollen and nectar, and then we keep them in a room that is dark or is under red light so which they can't see.

So we have a whole set of experiments designed that we'll be using these colonies for.

They all have to do with either how they all collectively partition the work in the nest, or they have to do with larval development.

So, there's still a lot of mystery there in terms of what's turning a bumblebee larva into a queen.

So in honeybees, the workers will feed the larvae royal jelly, and female larvae that eat this protein complex, they will develop into a queen.

Bumblebees don't have royal jelly.

They have some other mechanism that they're using to produce queens.

So there is some evidence in bumblebees that the way you make a queen is, you feed a larva more pollen and nectar when they're developing, but it looks like there are other factors, too.

So when a bee comes along and feeds, she'll regurgitate, and we actually don't know that much about what's even in the bee barf.

You collect the bee barf two different fundamental ways, so one way is, you can squeeze a bee, sort of force it to regurgitate.

It's just a gentle squeezing, but one of the issues with that is, when they're actually feeding brood, they're probably also adding other things from the head glands, so the second way that you can collect the regurgitate is, you sit and wait for a feeding event to happen, but you immediately pipette out the regurgitate.

One of the things that is in the bee regurgitate are large proteins, so we're looking at those, trying to figure out what they are, and then we're also going to be looking at small RNAs, these micro-RNAs.

They can control gene expression in the individual that consumes the regurgitate.

For people that want to know how we can more effectively rear bumblebees and use them for pollination services, there's a benefit to knowing what sorts of things actually turn a larva into a queen versus a worker, knowing something about how development actually happens.

If we know those things, then we can potentially help control it.

So something that we really want to be able to do is create a system where we can feed larvae what we want to feed them so we can experimentally figure out the factors that influence their development.

Bumblebees are our nation's single most economically important native pollinator.

In many places, it's getting hotter.

There's less food around, so understanding the thermal biology of bumblebees and the nutritional biology, that's really driving a lot of the research.