The mystery of the dead drones

I wasn’t going to write about this until I figured it out, but I’m coming up blank. On July 5, I checked my top-bar hive and saw a massive pile of dead bees on the ground just outside the entrance. My first thought: pesticide kill. I’ve seen pesticide kills before and it looked just the same.

But the hive was churning with bees. With my hive tool, I sifted through the mound of dead bodies and discovered it was all drones—thousands of them. Not drone pupae, but fully–formed adults. Heaps of dead drones are not unusual as fall approaches and drone eviction is well under way, but this was the beginning of July. What was going on?

Unlike the rest of the country, the Pacific Northwest coast had a cold and wet spring. In fact, now that July is more than half gone, I am still wearing a jacket on most days. Up through July 5 we were still having days in the 60s and nights in the 40s. The bees couldn’t possibly think it was summer, but did they think it was fall? Were they evicting drones prematurely based on the temperature?

There is no dearth as of yet, the forest and fields where I live are laden with wildflowers producing both nectar and pollen. And since the rainy season wasn’t over by July 5—and it still hasn’t quite given up—water was plentiful.

Someone suggested the hive might be queenless. I’m not sure I follow: Do queenless hives eject drones? I’ve never heard of that. But I checked anyway. Although I didn’t find the queen, I found young brood, sealed brood (including more drones) and scads of honey and pollen.

Now almost two weeks later, nothing has changed. The hive is abustle with bees that are bearding on the front and underside of their home every day even though the days are mild and the nights are chilly. They remained camped outside during several days of thunderstorms, and they were even festooning in long strings from the landing board. I didn’t see any evidence of swarming or swarm preparation.

As far as I can tell everything looks normal except the boneyard out front. I thoroughly checked my other hives—all Langstroths—and found no dead drones anywhere. So, I’m looking for theories. Does anyone have a thought?

Rusty
HoneyBeeSuite

Dead drones under the top-bar hive. All the dark material you see laying around is composed of dried and crispy drones as well.
Dead drones under the top-bar hive. All the dark material you see laying around is composed of dried and crispy drones as well.
Bearding on the top-bar hive. You can barely see the three hive openings.
Bearding on the top-bar hive. You can barely see the three hive openings.
You can see bees bearding under the top-hive as well as in front. They have a screened bottom board that they are hanging from.
You can see bees bearding under the top-hive as well as in front. They have a screened bottom board that they are hanging from.

Comments

Bill
Reply

Rocky,

How are the honey stores for this hive? Maybe with the cool weather, they are not gathering enough nectar. So, drones are cheap and are no help to this hive surviving. So, out they go and many times are stung to death.

Just a thought!

Bill

Rusty
Reply

Bill,

I saw lots of honey in there but not a lot if you consider the total population of the hive. Interesting idea.

Sam
Reply

I have no idea about the dead drones; I had a similar thing happen with one of my hives this year though. My thinking was that they were being ejected for hygienic reasons, or the drones were to weak to fly so they ended up dead in front of my hive in a stinking pile.

When I had tbh’s I noticed a huge amount of bearding even on cold days, this is one reason I do not use tbh’s anymore since the comb is arranged across the length of the hive creating a space with the worst possible airflow. When I started using warres I had them “warm ways” with the comb across the entrance, I was getting a lot of bearding that would last all night, since turning them “cold ways” comb edge wise to the entrance they never stay out in the evening, plus it drastically cut down on cross combing (no foundation).

mbee
Reply

Rusty, I saw the same thing this year in my two most populous hives and concluded they were trying to conserve resources. The colonies built up something fierce during the early spring maple flow, but by June they were out of stores. And here, at least, the blackberries didn’t start flowering until right around July 4th.

Looks like our timing is similar, so my vote is for Bill’s theory.

Sam
Reply

I know I’m in a different local but I have noticed a large reduction in the number of drones flying from just last month. No piles though just not many of them were before there were hundreds. Probably seasonal since swarming seems to have stopped in the area

Michael
Reply

Could the drones have been exposed to some pesticide or poison at a drone congregation site, away from the hive? I think I have read that one way to tell if a dead bee has been poisoned is if its tongue is sticking out.

Rusty
Reply

Michael,

That’s an original thought. Seems kind of crazy but the wind takes pesticide-laden soil and carries it for miles, so I suppose it could happen. Or they could get caught in an aerial spray or even a ground spray on a windy day. Interesting, thanks.

Aram
Reply

Rusty,

The closest that I have gotten to July drone eviction was when I moved my hive from one location to another, 20 feet away. The field bees all moved to the old location where a nice nuc was waiting for them. So the hive remained with all of the young brood, the queen and the nurse bees. Foragers were gone, no incoming nectar. Two days later the first foragers were formed, next day the drones were all evicted. Three nurses at a time would chase them out. If the drone did not get the idea they’d start chewing off wings, legs etc. So a feeding load on a colony plus no incoming food got rid of drone in a hurry.

Another idea, this type of hive is a drone breeding heaven. Could it be that a drone-unit is a lot more disposable than in a hive with a low drone count?

Rusty
Reply

Aram,

More interesting ideas. I’m wondering if the spell of rainy weather may have caused it. As in your situation, suddenly no nectar was coming in. So the bees may have evicted the drones to conserve resources. And you are right, a TBH is a drone-producing factory, so maybe they are considered highly expendable. Now that the rain has decreased, the drone eviction seems to have slowed as well.

Ricardo
Reply

Hi there!

Although we are in different parts of the globe, this year I saw hives that had this behavior at a time which is not usual (March/April). I inspected these hives and noticed a great lack of reserves, particularly in the most populous hives, the frames and supers were very light. At some point I noticed an unusual lack of pollen in the hives, this year the weather was very strange . . .
In my case I also had drone pupae expelled, and not only adult drones. In another apiary I also observed this behavior only in the TBH I have there, and not in the other hives.

Rusty
Reply

Ricardo,

This sounds very similar. Perhaps this behavior is more common than I thought. I’m going to open up my TBH today to have another look. We are still having strange weather, rainy and cold, which is very uncommon for late July.

Jeff
Reply

Hey Rusty,

I was checking one of my the colonies on the dairy farm and I noticed a load of drones on the bottom board. As I walked closer I noticed a load of dead drones on the rocks directly below the bottom board. This summer has been amazing in Newfoundland with record honey by local beekeepers and we had rain for the first time 2 days in a row all summer. So after two days of rain and being locked in for another half day there were loads of dead drones on the ground just from this one colony.

There was no issue with the other 5 adjacent colonies. Also this queen is a dark queen, so that could be part of the reason.

Funny how it goes.

Susan
Reply

Why are there a dozen worker bees, with pollen-laden baskets, dying in the grass in front of the hive? They acted like they were too tired to make it into the hive. Most bees were flying into the hive, but some were just falling into the grass in front of the hive and staying there. They are dying. It was the very end of the day. Maybe the grass was wet or the temperature suddenly got too cold.

Craig
Reply

So here is another possibility: I noticed this happening with my hive lately. Just drones, not workers, dead at the entrance. My hive recently swarmed about 3 weeks ago (caught the swarm!), and before this, I noticed a very high drone population (I have Langstroth hives). I did check and found my queen and that she wasn’t just laying drones. She does have the option to lay either a worker egg or drone egg in any given cell, and that could partly be decided by the size of the cell. My understanding is that different worker bees are delegated to different jobs based on their age. Perhaps either your queen and/or workers delegated to making comb produced a high percentage of drones in your hive, and then the workers delegated to hygienics (or some other category like drone patrol?) decided there were too many drones and started rolling heads.

Reggie
Reply

I have been having the same problem with my bees recently, and just came across this post in a search to find out what is going on.

We have had months of constant rain this summer, and I noticed the honey production in my hive slowing at the same time as the number of dead drones around the hive is increasing. I was concerned I had mites or some other invader, but the hive otherwise looks fine.

I wonder now if Bill’s theory can explain everything I am seeing. Thanks for the help!

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