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Counting the dead bees

You stroll past your hive for a quick peek and are dismayed to find five dead bees on the landing board. What does that mean? Is your hive in trouble? What should you do?

I can’t stress this enough: five dead bees is nothing. Nothing. The only difference between those five and a thousand of their sisters, is they happened to fall on the landing board. You aren’t worried about the other thousand because they fell somewhere else, a place where you can’t see them or count them.

I’ve read many estimates for the number of bees that die daily during foraging season, but depending on the size of the colony and local conditions, the real number is probably between 800 to 1200. For the sake of argument, I’m going to say 1000, which I think is a reasonable number.

The average lifespan of a worker bee

The first thing to consider is the average lifespan of an adult worker bee. For a healthy worker when all is going well, that lifespan is somewhere around 4 to 6 weeks. The period begins when the bee emerges from her brood cell and ends when she dies of old age or misadventure.

Old age is self explanatory and is often expressed by worn wings and hairless bodies. Misadventure can be due to anything, such as tangling with a spider web, getting blown away by the wind or smashed by a car, or getting diced by a lawn mower. As we humans say, stuff happens.

It turns out that four to six weeks is the number commonly cited for the average adult lifespan of most bees. That includes your mason bees, leafcutters, sweat bees, and miners. Basically, that’s how long bees working in the field live. The native bees emerge from their nests in spring and spend the next four to six weeks building a nest and laying eggs. They continue building until they die, and their offspring remain in the nest until the following year.

So in regard to an individual’s lifespan, honey bees are not unique. What is unique about honey bees is their ability to raise “winter bees” also know as diutinus or long-lasting bees. These bees are the ones that live inside the nest, survive the winter, and kickstart the colony the following spring. But that is another subject.

The egg-laying machine

The second thing to consider in a normal colony is the egg-laying ability of the queen. This number also varies, and I’ve read estimates that range from 1000 to 3000 eggs per day. To raise this many eggs, the colony needs a large force of healthy workers. Even so, we’re talking about a lot of eggs. Let’s take an average estimate of 2000 eggs per day during peak season.

Now, not all the eggs will grow into viable adults. Some will die at each stage of development. Let’s be conservative and say 80% reach adulthood. That’s .8 x 2000 or 1600 newly-hatched bees per day. If 1000 adults die during that one-day period, you still have a net gain of 600 bees. At the end of a month you have 600 x 30 or 18,000 more bees than you started with, even with losing 1000 per day. If 90% reach adulthood, you get 24,000 extra bees by the end of a month, which equals a good size swarm.

Yes, these are estimates based on averages, but they paint a picture. If you didn’t have all those bees dying each and every day, things would soon be out of control. If you took 90% of 2000 x 30 without deleting the dead ones, you’d have 54,000 additional bees at the end of a month—another whole colony. At the end of six months, you would have seven full-sized colonies. But it doesn’t work that way.

My point in reviewing the numbers is to illustrate that the daily loss of bees is much greater that we realize. The fact that we don’t see the dead, coupled with enormous amounts of brood rearing, lulls us into thinking that bees don’t die. In fact, nothing could be further from the truth.

Rusty
Honey Bee Suite

Bee-on-squash-leaf
Like most adult bees, a healthy honey bee worker lives about four to six weeks in the spring and summer months. © Rusty Burlew.

Comments

Sandra
Reply

Have you ever tried planting Euphorbia lathers (mole plant) for mole control? I checked your honey bee plant list and do not see this little beauty. Do you think the bees would not use nectar from this somewhat toxic plant? I was worrying about contaminating my honey with Euphorbia nectar.

Rusty
Reply

Sandra,

I did plant them once but they didn’t grow, so I don’t know anything about the nectar and I still have moles.

Steve
Reply

I have heard the 4-6 week lifespan, but where is a reference for that? I have an africanized hive that I requeened 2 months ago. I checked on them this past weekend and was again covered by a thousand stinging bees while I went through some frames until I found my marked queen. With a 3 week brood cycle, it’s been 6 weeks since the last africanized brood emerged. This is the second hive this has happened to me with, so to me it’s looking like either africanized bees live 8-10 weeks, or the 4-6 week number is one of those propagated myths that become fact. Let me know what you think. Thanks.

Rusty
Reply

Steve,

There are lots of references for the lifespan of a bee. On page 80 of The Hive and the Honey Bee (2015) the author says 4-6 weeks for spring and summer workers and 3-5 weeks for drones. On page 96 the same author says worker lifespan is 20-35 days for European honey bees (which is closer to 3-5 weeks) and 12-18 days for A.m. scutellata workers (which is more like 2-3 weeks) and the opposite of what you are saying. Of course, Africanized bees are a cross between these two, but I wouldn’t expect the lifetime to be longer than either, I would expect something in the middle.

Bill
Reply

Rusty,

I really like the bee photo. You take so many great photos I am jealous. I do not have that talent. Please consider a post of an album of your best honey bee or other pollinators. It would be a keeper.

Rusty
Reply

Thanks Bill. I have a wooden spool (like those used for cable) in my backyard that I use for a table. On top of it was a potted squash plant, ready for the garden. On top of that was this honey bee, just sitting there looking pretty.

I might consider putting together an album of favorites bee pics. It would be fun.

Andrew
Reply

Eloquent & informative, as ever. Thanks Rusty!

dan3008
Reply

Brill article 🙂 very reassuring for new beekeepers to understand bee death.
Although a quick correction. If each colony produced enough bees to make a whole new colony a month, you’d have more than 7 in 6 months, you’d have 64 colonies … That’d just be too many bees lol

Rusty
Reply

Dan,

You are absolutely right; I hadn’t looked at it that way before. I’d have to work through the math, though. Too funny.

Cooper
Reply

Yup. Just the nature of things. I still stop to help a struggling bee in a water trough or sometimes feel sorry for the bee that stings me. I was intrigued the other day at how the ants had set themselves up along a dirt horse path about 15 feet in front of a couple hives where the caretakers were dropping their deceased sisters. I always enjoy your blog, thanks.

AnubisBard
Reply

I just looked into my hive and saw the opposite problem. No brood at all. I’d peeked in a few weeks ago and the hive was so full that I figured it would swarm if I didn’t do anything. But things came up and I didn’t do anything. Now the hive has clearly dwindled somewhat (though it still looks like a vigorous hive), but no brood unless it’s hiding in the margins somewhere. I suspect that the colony did swarm and the new queen failed for some reason. Does that seem likely?

At this point, with zero brood, I don’t see anything to do about it, but give the considerable amount of nectar and honey remaining in the frames to my other colony. (I won’t do it until I’m sure there’s no queen in there, because this colony has convinced me it’s dead before, and somehow magically persisted. In three years, I have NEVER been able to find a queen in it.) The problem is the frames of nectar and honey are probably intermixed with stores from last fall – when I fed them sugar syrup, so if I do give it to the other colony I have to figure out some way to get the other colony to take it into the brood chamber so I can have clean honey supers when I put them on. Any suggestions? At this point I only have one colony, though my neighbor has another two. I guess this learning curve goes on for a while doesn’t it . . .

Rusty
Reply

Andy,

Remember that is takes two to three weeks from queen emergence to egg-laying, so be patient. As for the syrup/honey combination, can you save it for winter feed? Just freeze it and store it somewhere?

rachel
Reply

Thanks, this was perfect as I’m a new-bee and always feel bad when I see the dead bees on the landing board. I don’t want any of the bees to die.

Kris
Reply

I am actually grateful to see dead bees on the landing board and in the snow during the winter. It is a good sign that the colony is alive and well.

Rusty
Reply

Kris,

I agree.

sebastian
Reply

Rusty, this is a nice reminder, especially for new BK’s like myself who might be mortified (pun intended) by dead bees lying all around.

It seems like it’s important to learn how to distinguish between dead old bees with worn wings and dead young bees that exhibit signs of DWV. There’s a balance to maintain between careful observation and overreaction.

Rusty
Reply

So true.

Dale Puckett
Reply

When using entrance reducer in the fall, do I turn small entrance to the inside or up and down and will external feeder interfere with entrance.

Rusty
Reply

Dale,

The small entrance should be on the top of the bar (facing up) so that a layer of dead bees accumulating on the bottom board will not block the entrance. Whether it blocks the feeder depends on what kind you use; there are many designs. Just pick one that doesn’t interfere.

Richie
Reply

Rusty, However many bees that are hatched a day, die a day (on average). The way a colony increases in size is the 14 day (average) difference between days to hatch (21) and life expectancy of 35 days (average). Yes?

NOTTELLING
Reply

The bees are dying because of the cell phone towers; the radiation is messing with there heads and hurting them so bad it kills them.

Rusty
Reply

I disagree. Controlled experiments with cell phone radiation cannot produce those results.

Patrisha
Reply

Yeah I agree as well.

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