Monday morning myth: small-cell foundation discourages Varroa mites

The idea that small-cell foundation may limit the reproduction of Varroa mites resurfaces frequently. However, carefully controlled research has shown that mites may actually increase on small cell foundation. A carefully researched paper on the subject by Berry, Owens, and Delaplane was recently published in the journal Apidologie and can be downloaded here.

In the states, small-cell foundation has cells that are 4.9 mm wide and standard foundation has cells that are 5.3 mm wide. But what we now call “small cell” was actually the natural cell size back in the early 1900s. At that time bee breeders thought that they could improve on honey bees by growing bigger bees that would produce more honey.

They created these beasts by manufacturing foundation with larger cells. Sure enough, in not too many generations, the bee larvae filled the cells and the resulting adult bees were bigger. We are still using these “big bees” today.

Then in 1995 some scientists noticed that Africanized bees—which are slightly smaller than European bees—had lower mite counts. So the idea was born that the natural (smaller) cell size might impede the growth of Varroa mites. This idea was supported by earlier research that showed that when immature male mites are squeezed between the bee pupae and the cell walls, they often die.

With this in mind, beekeepers started regressing their colonies. That is, they tried to do the opposite of what the beekeepers in the early 1900s did: they provided smaller foundation in the hope that male mites would get squeezed to death in the tight confines of the smaller cells.

But, just as bees on large foundation grow bigger, bees on small foundation become smaller. So, in not too many generations, the male mites were no longer squished against the cell walls—and everything was just fine and dandy in mitedom.

This is not to say regressing to small cells is a bad thing. In fact, other research shows that natural sized bees may be more efficient pollinators and more healthy in general. But don’t count on small cells to take care of your mite problem . . . it just won’t happen.

Rusty
HoneyBeeSuite

Comments

Therel Utsey

I would like for you to give me some information on the small hive beetles. Is there a trap of some kind I could build or what can I do? I live near Charleston, South Carolina. Also one of my hives just swarmed. What should I do? Do I need to look in the hive? If so, how long before I go in? Thank you. I really enjoy reading all the information you put on the web . Thanks, Therel. I have three hives and I want to increase the number to about ten.

Rusty

Therel,

There are many kinds of plastic beetle traps available that fit in the hive and are usually filled with vegetable oil. They are very inexpensive so you can probably buy them cheaper than you can make them. Try the website at Brushy Mountain Bee Farm. They are close to you.

After your hive swarms you need to check to see that a new queen is replacing the old one. It will take awhile for the new queen to hatch, mature, mate, and start laying eggs. You should see some evidence of egg-laying within two to three weeks. If no eggs are showing up by then you will have to provide the hive with eggs and/or very young larvae, a swarm cell, a virgin queen, or a mated queen.

shelby

Back to small cell for a moment. I seem to remember one benefit being resistance to tracheal mites due to smaller bee.

bill castro

The upsizing of cell sizes done at the turn of the century resulted in many issues including the advancement of tracheal mites and eventually the perfect storm for varroa and brood diseases. If a colony is put on small cell foundation (SC) and allowed to regress through the season, that same colony will eventually no longer be pulling large sized cells for brood rearing. Most times bees will be pulling larger cell sizes for drones and honey stores while worker cells will be much smaller than modern conventional commercial foundations. Regression takes more than 1 season to accomplish, but with sincere patience and good management we can have bees that require nothing more than seasonal checks, splits for propagating, and harvesting the honey.

Sarah

When I was watching my honeybees on the bush honeysuckles this spring some seemed to be smaller than others. Can their size vary or am I imagining things?

Rusty

Sarah,

Yes. Size, coloring and lots of other things can vary. Remember that sister bees have the same mother but a variety of fathers.

Jim Whatley

Down here in Texas there’s a bee company called Bee Weaver. They were losing the mite battle by using chemicals and decided to let nature take its course. The bees that survived naturally were then used to breed their new colonies. They seem to be having great success for several years now without chemicals. It is true that their mite-resistant bee may be a little ‘hotter’ temperament due to Africanized influence. The honey production has been outstanding. I have a colony of their bees and although you do need your protective gear to work the hive, the bees don’t seem to notice me standing within a few feet of the hive.

I allowed my colony to build their own comb and am not using chemicals . . . we’ll see???

Rakesh

We have thought about bees but we need to do more research. We live in a subdivision and we are not sure how our neighbors would feel about it.

Aram

Bee Wrangler has done a few experiments with small cell. His conclusion was that 40 percent should be small cell, 40-50% larger cell, and 10-20% drone cell. I might be a little off on percentages, but I believe I am pretty close. In the fall/winter the center frames with small cells will be used to raise small cell bees, as the growing season proceeds and bees move to the periphery, they use large cells for summer bees. Larger bees are just a bit more efficient at nectar gathering. The drone cells will be used for drones and honey storage as needed. The most interesting finding was that bees will be larger in the summer regardless of the cell size. They just get better fed. All-small-cell hives are nearly impossible to maintain if one gets larger than a 5 frame nuc. They rework the frames for drones. Drones are such a cheap propagation method, and each worker’s genetic make up will have an equal chance of being spread out. With only 1 or 2 swarms per year, the virgin queen is unlikely to be a full sister to any worker bee.

Jim Whatley

According to ‘unscientific’ studies, it is said the mites are not necessarily reduced simply by cell or bee size. The positive results are gained by smaller bees being more vigorous in cleaning themselves (and others) of the mites and the mites fall harmlessly out the bottom of the hive. I would enjoy hearing other thoughts along (pro/con) about this theory.

Troy

I wish people would comment with an understanding between correlation and causality.

Varroa mites may correlate to early 20th century larger bees, but so does growth of automobiles and paved roads.

The question is one of causality: did bigger bees cause more ailments or not?

Until I see data that supports that, I believe that cars are equally likely to have caused bee disease increases over the past century.

Andrey

I’m not sure why Rusty talked about the size of the bees and squeezing of the mites in the article. Why don’t you be more open minded about it? What about the fact that the longer the the pupa stays in the cell the more mites will form? The sooner the pupa comes out the less mites are on it!

Rusty

Andrey,

I wrote about the size of bees and the squeezing of mites because that is the subject of my post.

Mike

Hello Rusty,

I’m a new beekeeper. my hive is from last summer. It is very strong, but I don’t think I had much to do with that. I have the hive for pollination on my farm. I have cherry, plums, pears, apples for fruits that I’m testing for compatibility where I live in Quebec, Canada. So, a few years ago I was dismayed to see the Japanese beetle in my fields attacking all my fruit plants.

I tried many homemade brews from the net but those that seemed to work, worked well on my plants as well! I do my own chipping and put some around my small cherry plants to control grass. Well, I have not had a Japanese beetle since, and that”s two years now. My hive is raised about 18 inches above ground and I spread wood chips on the ground. I don’t have any mites, not one and I’ve been looking since Christmas. Since this costs little to try I thought I might share this for everyone and see if this helps any.

Jim Whatley

Mike, could you share what type of wood you used for chips??? Or was it just a mixture of whatever. We have primarily juniper, oak, & mesquite.

Mike

Hello Jim,

It was a mix from the fence line but poplar was one. One other thing, the hive is along a machine shed made of cedar.

ORoedel

Scutellata and mite tolerance/resistance is another myth. Whoever had scuts and OBSERVED them, knows this fact. Scutellata migrate if they have a “problem” in the hive; they try to leave the problem behind.