Seasonal Bee Size

A smaller spring bee with her small cell reared sisters.

My test yard consisted of both large cell and small cell colonies.Determining which hives were large or small cell was impossible by observing flying forager bee size.

To understand what effect cell size and seasonal influences have on bee size, flying bees were measured from large and small cell hives through time. Measurements included:

  • bee length
  • wing length
  • thorax width
  • abdomen width

The data gathered indicates:

  • September – large cell bee sizes average larger than the small cell bees
  • November – both the small and large cell bees are essentially the same size
  • October to November – abdomen width increased for all colonies
  • February – newly hatched bees, in large and small cell hives, are small and look like the early spring small cell bees
  • May – most of the larger over wintered bees are gone. All bees are more uniformly sized and smaller
  • July – bees are slightly larger than in May. No typical spring small cell sized bees. Large cell bees measure slightly larger than the small cell bees. The differences are discernible by measuring but not by looking at bees at the hive entrance. No visible differences
  • August – bee sizes are beginning to diverge resulting in the slightly different sized September bees

After 1500 measurements, some differences in bee size, in a hive, through time can be seen. Probably because I’ve taken so many measurements. The differences are subtle, but visible.

Yet, I can’t tell the difference between the small cell and large cell bees without my records.There’s as much variation, throughout the year, within a hive, as there is between different cell size hives.

Situation – First Season

Large cell comb generates large bees. And small cell comb generates small bees. Right? That’s what small cell literature states. When the first spring brood hatched from my small cell hives, those bees were smaller than the over wintered bees raised on the larger cell sized comb.These small cell bees were visibly smaller and had a more tapered abdomen.

By midsummer, the over wintered, large cell bees had perished. Hives consisted of bees raised only on the small cell comb. These bees should be easy to spot in the field. Yet, when searching for them, I couldn’t find a single small cell appearing bee.

Barry Birkey had both large and small cell colonies. They contained fully regressed Lusbees. But, he couldn’t see any size difference between his foraging bees either.

That winter, I monitored a small cell hive in my backyard using a plexiglass inner cover. Those bees gradually got larger through the winter.

When the first brood hatched in the spring, the size difference size was apparent. The typical small cell sized bee was easy to recognize when compared to her over wintered small cell sisters. Did I have genetically large cell bees squeezed into a small cell comb?

Next March, I obtained several Lusbee nucs from southern Arizona. They contained fully regressed bees. These bees looked like the typical small spring bees seen in my small cell hives.They were noticeably smaller than my own over wintered small cell bees. It was summer in Arizona when I picked up the nucs and late winter in Wyoming.

One month later, I couldn’t see any size difference between my over wintered small cell bees and the Lusbees. I joked that they had filled up their canteens. 🙂

Second Season

This small spring bee is several days old. She’s much smaller than her small cell over wintered sisters.

Four years of severe drought had decimated the spring bee forage. And summer bee forage was looking rather bleak. Brood rearing was decreasing.

So, I fed the small cell bees with large cell frames filled with granulated honey.

  • a super of large cell feed was placed beneath an excluder, on the bottom board
  • the bees began moving the honey upward
  • the queens started laying more brood

Then, all those queens promptly squeezed through the excluder. They filled the bottom super of large cell sized comb with perfect wall to wall worker brood, not the drone brood that foretold in small cell literature.

The queens were moved above the excluder. Yet, most returned to the bottom box. It appeared the queens preferred to lay in the larger cell sized comb, even when open small cell comb existed above the excluder.

The excluders were removed.

Now these small cell hives had a full box of large cell brood! Were these small cell hives wrecked? Would they need treatment to resist the mites?

Not all was lost. The opportunity was accidentally created to compare large and small cell bees from:

  • the same hive
  • the same queen
  • at the same time

When the larger cell brood emerged, I returned expecting to see some fat, long, large cell sized bees. I couldn’t find a one! All the bees looked exactly the same. What was going on?

Third Season

I decided to expand my hive and yard count. Lacking enough small cell comb, I used both large cell and small cell comb in each hive. I put 4 to 6 small cell frames in the center of each large cell brood box.These hives prospered with:

  • no discernible size differences between the bees in each hive
  • natural mite drop remained low, about 1 mite/week

Natural Comb

A top bar hive was established from a small cell colony to observe natural comb. By season’s end, it was no longer large or small cell comb. But a full range of cell sizes grading from large to small. It was natural sized comb.

Large or Small Cell Bees?

If it isn’t large or small cell comb, is it large or small cell bees? Test time.

Three all large cell hives were started in clean equipment. Once established, I visually compare bee size difference between the large and small cell hives:

  • different bee races displayed some size differences
  • little size difference was seen between large cell hives and small cell hives

I could not tell, by looking at the bees, whether a hive was large or small cell. Maybe the old wrangler needs new glasses, huh 🙂

The Test

So, new glasses it was! Digital ones. Seasonal bee size was monitored and measured using photos were taken at each hive entrance. A scale was included in each shot. At least three shots were taken per month. Nine suitable bees were picked, per hive, per month, for measurements.

Some basic measurements were obtained. Bee length, wing length, thorax width, and abdominal width were chosen. The first three measurements are obvious. Abdominal width was measured at the front end of the third abdominal segment, in front of the tomenta.

These measurements were averaged for each hive. Then, they were compiled and averaged for all large cell hives. And again for all small cell hives.


The first five months of data are in. Here’s a summary of what I’ve measured so far:

Here are some measurements for a ‘typical’ large and a ‘typical’ small cell hive.

September large cell bees average larger than the small cell bees.

By November, both the small and large cell bees are essentially the same size even though they were raised on different size cell sized comb!

It’s also interesting to note the abdomen width increased, slightly, from October to November for both large and small cell bees. Maybe both the bees and beekeepers picked up a little width during the winter. 🙂

I had trouble getting enough bees for a good sample in December. I measured a few bees and have included the data, but don’t think it’s a random or a representative sample.

January’s sample was better than Decembers. Obtaining shots, of enough flying bees, during the winter, is difficult.

Enough is Enough

It’s February and new bees are hatching out in my large cell hives. They look like the early spring bees did in my small cell hives. I’ve measured enough. About 300 measurements were taken in a good round of samples. That’s about 1500 measurements over all. I don’t need to numerically quantify these observations for myself. I hope they give you something to think about.

I see some differences in bee size, in a hive, through time. Probably because I’ve taken so many measurements. The differences are subtle, but visible. But I still can’t tell the difference between the small cell and large cell bees without my records. There’s as much variation, throughout the year, within a hive, as there’s between different cell size hives. It’s obvious when different size bees occupy the same hive! Drifting isn’t a factor as one large cell hive is over 2 miles from the nearest known hive.

Follow Up

By May, many of the larger over wintered bees are gone. All bees are more uniformly sized and smaller.

By July, Most bees are slightly larger than they were in May. All of the typical spring small cell sized bees are gone. And it appears the large cell bees are slightly larger overall than the small cell bees. The differences are discernible by measuring but not by looking at bees at the hive entrance. Bee sizes between the large cell hive and the small cell hives are beginning to diverge and result in somewhat different sized bees as measured in September.

Other Reports

The March 2007 Bee Culture, page 18, has an interesting article on cell size versus bee size. I haven’t seen the original study, but this article reports about a 1% reduction in bee size, tracheal size, and some wing venation when Apis mellifera mellifera is placed on small cell comb. Those bees experienced a significant reduction of about 11% in body mass. And the small cell diameter was reduced about 8% in width after five months.

Apis m m is a much larger bee, in some characteristics up to 30% larger, than the bees available in the US. I would suspect that a smaller cell size would impact the development of this larger bee more than the it would our smaller bees. I doubt anyone could visually detect that 1% change in appearance between large and small cell bees. It’s probably within the natural size variation caused by other factors like genetics and nutrition. Maybe, I’m not as blind as I thought 🙂

That body mass change is exactly opposite of what is speculated in the small cell camp. Some thinking and observations need more work in the small cell camp.

Done For

This bee size test about did my beekeeping in. I’d been working on a series of bee/mite tests and experiments since 1996. Much of what I observed was obvious after a few years. But I kept plugging along doing mite counts and colony observations following my scientific training. Modifications were often made to answer the criticisms and short comings of my methods.

Looking back, extending those tests wasn’t a trivial matter. Too much time, effort and money were involved. Not to mention the impact it had on my family. None are beekeepers.

One day I realized that all the joy and wonder, I’d experience in beekeeping, was absent for some years. That I was stubbornly plodding along on just momentum. And that after the last 1500 bee measurements, I didn’t have any momentum left. My living no longer depended on the bees and I couldn’t find a reason for continuing with them. I made plans to sell or give them all away which ever would come first.

But that didn’t happen. The bees essentially managed themselves for over a year. I saw them about 3 times. And didn’t manage them at all.

After that, they were all thriving. Once setup on a clean, natural broodnest, they didn’t need any help.

Rather than having hives that were done for, my whole approach to beekeeping was done for instead.

Today, my beekeeping is different than before this test. I work them when I have the need. Not because the bees have need of me. For when given the proper situation, they don’t.

It’s a humbling revelation, especially for this intensive beekeeper. But it’s a liberating concept as well.

It took almost a decade, a bazillion mites, many dead hives, thousands of hours on the computer and 1500 bee measurements to finally get the truth through to me, that Natural is not only better for the bees, it’s better for the beekeeper. 🙂


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