Varroa resistant bees in Norway

It is positive that the research community is becoming increasingly focused on varro-resistant honeybees. The latest report comes from a doctoral student, Melissa Oddie. She has started an investigation why a Norwegian beekeeper’s population of bee colonies can be called resistant because, according to his information, he hasn’t treated his bees against varroa in at least 19 years. Their article is a pre-presentation before it is peer reviewed. It could be read and downloaded here when I was writing this: https://peerj.com/preprints/2976.pdf

The result showed that the varroa population of the test bees had a growth rate of 0.87, ie a decrease over time. While the non-resistant control colonies had a growth rate of 1.24, i.e. an increase of the mite population over time.

 

Positive details in the study

  1. One of the beekeeper’s own apiaries was used and its colonies were used in the test.. Thus, no queen was introduced to other types of bees in another place. The resistant bees and their queens were tested in their normal environment.
  2. The distance between the test and the control colonies were big, 60 km.

 

Details missing

  1. The name of the beekeeper. He had earned a place among the authors.
  2. The beekeeper has exchanged breeding material with another commercial beekeeper since 2004. This beekeeper has also not been treating his bees for many years.
  3. The number of bee colonies forming the resistant colony population is not mentioned.
  4. The cell size used by the beekeeper is 4.9 mm, ie small cellsize, for almost as many years as he did not treat against varroa.
  5. The cell size of the control colonies is also not mentioned. Is it also 4.9 mm or larger?
  6. It is not mentioned if there are other bees close to the test and control colonies. The test beekeeper has several apiaries. If any of them are near the test apiary, it would probably not affect the test. How many other type of bees could be found near the test and control apiaries (if any) is not mentioned and, if so, the distance to these bees. It is important for the reinvasion risk.
  7. Nothing is mentioned of annual losses for the years backwards for the test and control colonies. It may be of secondary significance and these figures may also not have been secured. However, some kind of data about of the losses at the beginning of the adaptation of the test bees could have been interesting to take part of. But the article is inspiring anyhow.
  8. There are also no tips for beekeepers inspired by their article to start developing their bees to become resistant. Of course, it is not a task of the test I understand, but some kind of comment about this has been positive since many beekeepers will certainly appreciate the article and be inspired by it. However, such advice I look forward to find in follow-up articles in bee magazines.

Small cell size important in breeding Varroa resistance

After reading the blogpost ”Breakthrough?” an European PhD-Scientist wrote me an email with the following comment:

After reading your post I realized that you do have small cell size, but you’re not mentioning it in the actual post. To make sure that the reader’s get the full picture, the main components of your management system, this should be explained for them.

For instance, for me it’s a fact, that the cellsize used in a selection program is a factor incorporated in the population just like springfeeding appears to create a dependency of that feed to make bees start an explosive spring behavior.

As our bees are still wild animals, you can select whatever you like (or forget to see as selection-factor) to specialize your bees. Feel very good that your selection works.

But looking at the picture I have, some more ’vitality’ comes with better Varroa control. More or less ’Race’-independent. Question for me: ’slight inbreeding effect’?”

A valuable comment which gives food for thought. Thanks!

Small cell size (SC) is so natural for me, that it’s the normal thing. I forget it sometimes. Those small quick bees flying directly into the entrance are what I expect when looking at a bee colony.

It’s interesting Eric Erickson in Tucson when he started his breeding project for Varroa resistance found that many survivors that he used in his program were on 5.1 mm cell size. This was quite smaller than the most common 5.4 mm. http://www.elgon.es/diary/?p=457

Eric_EricksonF Eric Erickson when I and Hans-Otto Johnsen visited him and Lenard Hines about ten years ago talking Varroa resistance.

Erickson is said to have been forced to retire earlier than he should have. He died earlier this year (2016) well above his 70th year. There were nice obituaries, but I couldn’t find a word about his Varroa resistance program. Strange.

Every spring since I started to take my bees down to small cell size, when I took care of the dead outs after winter I saw that many combs were poorly drawn. The bees had many times failed to follow the 4.9-pattern and drawn patches of sometimes bigger worker cells and sometimes a lot of drone cells. Also when managing struggling colonies during the season the same observation was many times made. This year very little of this was seen. But I still have some colonies that can’t follow the 4.9 pattern when drawing their own combs (but they do well on already drawn small cell combs, especially colonies with heritage from queens from other beekeepers I have found interesting to try.

At the same time I’m aware that there are beekeepers that havn’t treated against Varroa for many years that still use large cell sizes. I draw he conclusion that it is possible to keep bees on large cell size and still be treatment free. But I see very little reason for not going down in cell size. The most important reason is that the bees themselves go smaller when given the chance. It must have something to do with their fitness and survival, not actually in first place in relation to Varroa.

Concerning the earlier blog post “Breakthrough?” and that I have used very little Thymol this year. Last year at the end of July I had used Thymol on about 70% of the colonies. This year at the same time of the year I have used Thymol on 2 colonies out of about 150 (I had about 150 last year too). I find it hard to believe that the only reason would be a successful breeder queen. I think better pollen availability this year has given a better immune system. And reinvasion I think is less problematic. With the latter in mind, I can imagine that adaptation to better control the mites is developing in the bees. And the absence of chemicals, in this case thymol, do not disturb this adaptation.

Another change in management is that I don’t move bees between apiaries. When making splits they stay in the same apiary. If there’s only one colony in a yard I split that colony and build up the apiary again this way (from now on). Some minor movements of bees have been done though.

Learning and teaching

 

Hans-Otto Johnsen was very skilled already in his youth keeping old American cars and trucks going. That skill can be very handy for a commercial beekeeper.

For many years he worked as an expert on explosives, but he got poisoned by nitroglycerine and had to change his job for making a living, so he turned to beekeeping.

At the university

For a number of years he worked as a technician under Prof. Stig Omholt in Norway and at the same time developing his commercial operation. His experience from these years has helped him in developing his Varroa resistant bee stock.

HAns-Otto brood A good brood comb in one of his Norwegian type of combs before he switched to medium Langstroth size.

Quite soon he got to know me and wanted Elgon stock to work with. He imported quite a number of splits from me. He kept track of the Varroa levels in the colonies and stopped using any type of chemical to fight anything in the hives. He wanted his bees to develop their ability to survive, which they did.

Hans-Otto & Ed Ed Lusby and Hans-Otto discussing small cell beekeeping at a fuel filling stop on our way to one of the apiaries of Lusbys’ in the Sonoran desert.

In America

We travelled together several times to America and studied small cell beekeepers and wax foundation producers. Hans-Otto bought equipment and started producing wax foundation, small cell and large cell as well as different sizes of drone foundation. His mechanical and engineer abilities showed themselves to be very useful as he changed and improved the equipment, for example the cooling of the drum for producing rolls of uniform sheet for feeding the plain and foundation rollers. Also the setup of plain and foundation rollers needed according to his opinion more controls of individual speeds for different parts of the production process, which he included in the setup.

Hans-Otto and GAry Dadnt Hans-Otto and Gary Dadant discussing wax foundation production during a visit with Dadant’s in Hamilton.

Research

He started to plan and set up different tests for looking at the effects of different cell sizes in brood combs and to produce virus free drones to mate with virgin queens. He saw that bees easier recognized (and removed) when drone brood was infested with mites when these cells were smaller, which they naturally are with smaller worker brood cells. He also saw that mites more readily infested the biggest drone cells.

He was involved in small cell tests, of his own and together with others. One can be found here: http://beesource.com/point-of-view/hans-otto-johnsen/survival-of-a-commercial-beekeeper-in-norway/

Today Hans-Otto has research money from the Department of Agriculture in Norway.

Resistant stock

He developed his bees in quite isolated areas, but not totally isolated, so sometimes the bees were mated to carniolans, buckfasts and the native brown bee (Mellifera mellifera). He also worked together with Terje Reinertsen, another Norwegian beekeeper, very similar to him when it comes to beekeeping. They exchanged breeding material. Both of them have discovered that their bees teach other bees how to get rid of mites. It seems this ability to teach new bees is very important knowledge when developing a Varroa resistant stock.

Today Hans-Otto hasn’t treated his bees for 15 years. The levels of mites are normally very low in his and Terje’s colonies and he never sees any wingless bees. In 2014 the bees of Terje were tested for Varroa levels by the Norwegian Beekeeping Association in preparation for planned research. (Birøkteren, vol 131, 2015(1), pages 13 and 24. The Bee Journal of the Norwegian Beekeepers Association.) The levels were so low it was difficult to calculate the reproduction rate.

When Hans-Otto moves his bees to the heather in late summer, for producing heather honey, his bees quickly pick up quite some mites. The natural downfall of mites will then be higher until about a month before the frost will make the bees form winter cluster. Then the downfall is almost zero again.

Book contribution

In 2010 Georgia Pellegrini (https://en.wikipedia.org/wiki/Georgia_Pellegrini) published her first book on natural food: Food Heroes (http://www.amazon.com/Food-Heroes-Culinary-Preserving-Tradition/dp/1584798548) She included a chapter about Hans-Otto and his focus on natural production of honey. For example he concludes that small cell bees are more biologically optimized than large cell bees. Thus research done with small cell bees are more reliable concerning what bees are and how they react naturally. In short, research results with small bees are more reliable.

In this context it’s interesting to notify that Norwegian wax is almost pesticide free.

HansOttoJohnsen An important part in his quality control is producing wax foundation as he thinks will be the best help for the bees.

Learning and teaching

Today we understand that adaptation of bees to fighting Varroa isn’t only selection breeding, natural or beekeepers’, for changing the DNA composition, but also epigenteic adaptation, the change of expression of the DNA as a result of changed environmental pressure on the bees. This turns the focus to the importance of locally adapted bee stock. Now research is going on with a third adaptation step, how bees learn how to deal with challenges and how they pass on this knowledge to other bees, worker bees to worker bees.

Hans-Otto caught a carniolan swarm of not resistant large bees that choose one of his swarm traps for their new home. After establishing this swarm in one of his apiaries he shifted its place with one of his resistant colonies. So this nonresistant colony received the field bees of a resistant colony. Afterwards they both behaved like resistant colonies.

One year he bough buckfast virgin queens not selected for Varroa resistance. He put them in splits made from his bees. The virgins mated in his apiaries. These splits were spread out in different apiaries of his. For two years they kept their colonies working fine and resistant to mites as good as his other colonies.

Now these two experiments absolutely are food for thought.

More than15 minutes of fame

Definitely Hans-Otto Johnsen is worthy of more than the 15 minutes of fame, one commentator thought was enough.

More Varroa resistant bees

Darrel Jones lives in a rural area in northern Alabama. He is an enthusiastic grower of heirloom tomatoes, http://www.selectedplants.com/ Being a beekeeper as well is a natural fit with his gardening activities. Keeping bees treatment free was his goal from the time he first saw varroa mites in 1993.

Darrel Brandypeace Brandypeace, an heirloom tomato of Darrel Jones.

In 2004 he found a single feral swarm that showed significant varroa tolerance. He saw a lot of hygienic behavior and uncapped pupae with mites combined with very low overall mite numbers. It showed some unwanted characteristics as well with a high stinging tendency and yearly swarming. He concluded that the swarm was a combination of typical Apis mellifera mellifera with Italian bees. The bees flew at low temperatures and overwintered on very small amount of honey reserves.

Digital StillCamera A feral swarm

Combination partner

He purchased 10 queens of mite tolerant stock from Dann Purvis and used them as drone source colonies next year when he raised queens from his feral tolerant swarm. A couple of years he deliberately encouraged his new colonies to swarm planning they would stay in the vicinity and establish a good buffer of resistant drones for his virgins to mate with. He pushed more than 60 swarms into the woods.

Darrel Purvis

Darrel says there are many feral bees living in the forest around where he lives. And he catches some feral swarms in swarm traps every year. He could easily catch more if he wanted to.

Darrel natur Forest area in Alabama.

Breeding better beekeepers’ bees

There are about 100 managed colonies some miles east of him, but they are far enough away that there is no risk of interfering with the matings of his virgin queens. His conclusion is that they don’t interfere with the matings of his virgins. At least to any degree it matters.

Today he has 14 colonies in four apiaries. One apiary is far away (200 km) from any other bees including his own. This apiary gives him possibility to mate virgins somewhat differently or with an experimental drone source.

 

Bringing in external mite resistant stock

In 2011 he bought 3 queens from Mike Carpenter. Mike has been selecting for bees that groom and injure mites (Allogrooming, bees grooming each other from mites). Darrel wants to combine different varroa resistant traits in his stock and also reduce stinging tendency and swarming behavior.

He bought 3 queens from Bweaver in 2015. These bees are advertised as treatment free and from evaluation, are very hygienic. He found the resulting colonies to have good temper but they produced many swarms out of the normal swarming season.

The traits he is selecting for in his breeding are decent honey production with at least 60 pounds per year, very high mite tolerance, good quality honey, and overwintering with small clusters that build up very fast in spring. He selects against high tendency to swarm and aggressive behavior. He is not satisfied here yet, but working on it.

 

Africanized bees

Africanized bees are not currently present in North Alabama. Cold winter temperatures will prevent highly Africanized stock from surviving in his climate. They probably will be able to survive if crossed with bees that form clusters and winter well.

Bweaver is situated in Texas, declared as heavily Africanized. Their bees show significant introgression of traits but without the increased stinging impulse typical of Africanized bees. Darrel has decided to replace the 3 queens he bought from there, with his own stock, which winters better. He says Africanized bees have some good traits that could be exploited in combination breeding

 

Spreading the stock

His goal is to spread treatment free stock in the surrounding area. For this reason, he has sold a total of 25 colonies to 3 local beekeepers. They too are also keeping their bees treatment free. Darrel has an agreement with these three beekeepers to share stock when it comes to raising queens from the best breeders. In 2016, he plans to make another 10 colonies to start other beekeepers with mite tolerant bees.

 

Cell size

He uses standard Langstroth equipment with 11 frames (instead of 10) and 31 mm end bars (instead of 35 mm). He also uses small cell 4.9 mm wax foundation. He has a few colonies on 5.3 mm cell size and sees no difference in varroa tolerance or honey production. But the large cell colonies build up slower in spring. This is a bad factor for him and he doesn’t produce any more colonies on 5.3 mm.

Darrel Cellmätning How to measure cell size. You can do three ways on a comb, or foundation. Two ways diagonal as well as straight.

 

Infestation level

Darrel does not do any mite level checks. They are not necessary as he never has seen any big die offs or any bees with virus or wingless bees with DWV. He did check one random colony in 2014 to see how many mites were dropping naturally. Some other beekeepers had asked because they thought his bees were full of mites. This colony dropped 15 mites in 48 days proving them wrong. This makes a downfall of 0.3 mites per day.

 

Conditions and characteristics for Darrel Jones’ resistant stock

  • His area is relatively isolated from nonresistant bees.
  • A large population of feral resistant bees are established in the vicinity. This is quite a different situation compared especially to many European areas with bees.
  • He began with bee stocks that have excellent resistant traits.
  • He is not bringing in non-resistant bees in the form of queens, nucs, or colonies.
  • He is at most trying a few new queens from outside per year.
  • Small cell size is positive for colony build up but not necessary for resistance.
  • No treatments of any kind have been used for the last 11 years. Natural mite resistance in his bees is enough that they are thriving.
  • Yearly sales of honey pay all expenses to sustain his beekeeping activities.

 

 

A locally adapted Varroa resistant bee stock

Reid Hives

http://www.happyhollowhoney.com/

Richard Reid in a Virgina rural area in the US began with bees 1973. Beekeeping was simple, almost only it consisted of putting on and removing supers.

By 1995 all of his bees died due to the Varroa mite. He didn’t like drugs and didn’t use any in his colonies. A package bee colony he bought also died, after only two months. He couldn’t take more, dropped the bees, and devoted himself entirely to his construction business.

 

Survivors

After a number of years, he discovered that a few swarms had settled in a few stacks of supers. He went and looked at these wild bees sometimes and saw that they lived on. They lived and swarmed for 12 years unattended. After a few years he was encouraged and decided in 2008 to give beekeeping a chance again.

Reid feral12 One of the feral swarms settled in his stacks of supers.

There are no big farms nearby (thus not so much of agriculture chemicals) and some smaller beekeepers were at least 3 km (2 miles) away from his bees. So the conditions for healthy beekeeping was good.

 

Come back

He took care of the two feral swarms and began to expand the number of colonies using these, VSH, and Russian lines. He decided again not to use any kind of chemicals against Varroa. He didn’t buy any package bees or colonies from other areas (well, none at all). He multiplied his own colonies.

Reid SwarmtrapBox He also catches some swarms.
He bought however queens from different places which he believed to have resistance characteristics, VSH Carnica, Russian bees, and survivor bees from different places. He never monitored mite levels in his colonies.
Annual losses since 2008 have been between 10-15%, except after the winter of 2012-13 when 40% died. Each year, he had seen some wingless bees in some colonies. After the winter with the big losses he hasn’t seen any wingless bees. He has since bought fewer queens from outside and bred most from his own.
Every year he breeds from several “lines”, now about 18 of them. Queens are mated in his home yard. He makes many splits every year. Some of these get pupae of those he breeds. Some splits rear queens themselves.

Reid queen One of his queens.

 

Increasing

2015 he wintered 75 production colonies and 105 nucs. 30 of the colonies are kept in the vicinity of his home yard. There he keeps 17 of them. The nucs are also kept close in the home yard.

Reid Hives&Nucs Some of his nucs and production colonies in his home yard.

He has altogether nine apiaries. He wants to have at least 10 colonies in each apiary, but he hasn’t reached that goal yet for most of them. He is now aiming to increase his number of production colonies to 100 and the nucs to 150, as well as an additional 2 apiaries.
Regarding cell size, the great majority of brood frames in his colonies are Mann Lakes standard plastic frame with plastic foundation. (http://www.mannlakeltd.com/beekeeping-supplies/category/page19.html) The cell size on those are 4.95 mm. The rest of the frames in the honey boxes have a larger cell size. Some frames are started without a foundation. The intention is that the bees will build some drone comb there. He wants to flood the area with desired drones. But bees are also building fine worker brood in some of these frames, especially in the nucs.

 

Selling nucs, queens and honey

He split the nucs in the spring and sells one part with the queen, saves the rest to build up a new nuc. It’s usually used for a mating nuc or nuc production depending on the season.

Reid Brood One of the worker brood frames built by the bees without the help of a foundation.

He usually has a very good spring flow that will carry the colonies through the rest of the year, but there’s usually a dearth in the summer, which means the nucs may need to be fed sugar syrup to prepare for winter. 2015 he had so much spring honey production, he only had to feed about 20% of the nucs for winter.

He says that now he has enough resources so he can share honey between production hives and nucs. Thus he feeds less. He usually only feeds a handful of production hives (mostly new ones) to prepare for winter. The production colonies go through winter on large supplies of honey. Quite often he has extracted honey in April. You can say he uses his colonies as a honey storage.

 

Richard Reid’s locally adapted Varroa-resistant bee stock

• There are at least 3 km to apiaries with other bee colonies than of his stock.
• The area where he lives is not a highly developed agricultural area, so there is not so much agricultural chemicals there as can be the case in many other areas.
• He started with bees which had a degree of varroa resistance.
• In most brood combs, he uses small cell size.
• He doesn’t bring in colonies (such as packages) from outside the area with his bees.
• He splits nucs (with new queens from his breeder queens) to make more nucs, which later become production colonies or bees for sale. He also splits a few of the smaller, less productive, production colonies to create new nucs.

• He doesn’t requeen on a regular schedule. He has some colonies with queens finishing their 3rd and 4th season.
• The bad colonies die or have their queens replaced.
• He breeds after queens from many different lines each year.
• He tries each year just a few queens from other breeders.

 

Encouragement to all beekeepers

Richard Reid is one of several beekeepers who has managed to breed a varroa resistant locally adapted bee stock. Let us be encouraged by that and despite what some other beekeepers of all kinds say, that this is not possible. How can one be so ignorant to what others achieve? Make use of what you can of the experiences of Richard Reid.
When he started, he hadn’t many bee colonies, so even if you have few colonies you can do something.

Perhaps your circumstances are such that it is good to monitor mite levels in your colonies. There are various methods, for example the Bee Shaker (http://www.elgon.es/diary/?cat=85).

Don’t take it as a failure if you choose to use pesticides at times. Each of us decides what is appropriate for ourselves and our bees, in consultation with the laws of your country. A treatment that doesn’t involve any chemicals at all is to remove all capped brood (worker and drone brood) twice, a week apart. It is effective, weakens the bee population as well though, but not the health of the bees. The bad colonies get new queens as soon as possible.

Next season will always be better!

Cell size affects water content

I started taking down my bees to small cell size 15 years ago. 10 years ago I had combs with 4.9 mm, 5.1 mm and 5.4 mm cell size in the supers. At one time I did some measurements of moisture content in honey from the capped cells in supers.

The supers were square sized for 12-frame Shallows. Single walled wood, not very thick to keep the weight down. Almost all my supers are like that. I measured moisture content in honey from cells close to the top of the frame, in the middle. When comparing the different cell sizes in the same box it was done from two frames, comb sides next to each other.

What I found then was that the moisture content in the center of the box was 1% lower than from the outer combs. This was the case when all combs in the super had the same cell size. I speculated that this was due, at least partly, to the fact that the uninsulated walls of the super made the temperature vary more in the super during day and night, especially close to the walls. During nights water drops could well be formed on the outer frames. And the honey could thus take up more moisture.

The moisture content was then 1% lower in cell size 5.1 than in 5.4. And it was 1% lower in 4.9 compared to 5.1.

The moisture content was so low in the smaller cell sizes that I became braver to harvest combs that were not fully capped. I started harvesting whole boxes even if the outer combs was not fully covered or even 2/3 covered. Sometimes outer combs were and also are today only capped at the top. Shallow frames are low, 137 mm, so it will not be as large area of ​​non-capped honey compared to a higher frame where only uppermost part of the honey is covered.

Water content in my honey is usually around 16-17%, rarely above 18%, sometimes below 16%. Before I used small cell size, moisture content was often around 18%, even though I tried to harvest only capped honey.

Project with plastic frames and insulated boxes

This year (preparations began last year) we (I and two others) started a project to test a number of different things (will probably come back with a report). The project uses insulated plastic foam supers for 10-frame Medium frames (159 mm high). All frames are supposed to be plastic with plastic foundation. Two different cell sizes are used, 4.95 mm and 5.5 mm. Thus a group of colonies have only 4.95 and another group 5.5. Not all combs are completely that way in all colonies. Next year it will.
Vettenhalt Yellow plastic frames with 4.95 mm cellsize and black with 5.5 mm.

Low moisture Heather honey

This year cell sizes were somewhat mixed for different reasons, especially in supers. So when I harvested a number of supers with well capped Heather honey combs with different cell sizes in the same super I took the opportunity to measure the moisture content again in a similar way as 10 years ago.

This time, I could compare 4.95 with 5.5. And 5.3 with 5.5 (I had some plastic frames with cell size 5.3 also for a certain reason I will come back to in the report to come).
The notes I had from the test 10 years ago I have not found. But I found those I made this year. They are seen in the table.

Super

4.95 mm 5.3 mm 5.5 mm capped honey

uncapped honey

1

16.0% 17.0% X
2 16.5% 17.5% X
3 16.0% 16.2% X
4 17.0% 17.3% X
5 15.9% 16.0% X

 

Similarities and differences

The tendency that smaller cell sizes means less moisture in the honey holds. But the differences between cell sizes are smaller this time. Another difference is that the difference between the middle frames and the outer ones in supers with the same cell size was not found now with well insulated supers.

The difference between the cell sizes are greatest when 5.3 and 4.95 are compared. The difference between 5.3 and 5.5 was not as big (not per 0.1 mm cell size either).
The moisture content was for me surprisingly low considering that it was almost pure heather honey in the combs checked. Usually Heather honey has higher moisture content, probably due to it’s gathered late in season when temperature difference between day and night is bigger. But it was unusually warm in August this year when the Heather was in bloom and remperature was not very low in nights.

When trying to understand the results I think it helps being aware that when bee colonies build their own combs without the help of foundation many have observed they build (when they are adapted after a period of perhaps several years) mostly between about 4.7 and 5.1 mm cell size in the brood nest and 5.2-5.5 (approximately) in honey area.

When the bees have collected a lot of honey for the winter period, most of the empty cells are small. When spring comes the first brood is reared in small cells. Low moisture honey is closest to brood then. Is that of any importance for the bees? Later in season some brood is reared in slightly larger cells as well. Towards the end of the season the queen lays almost only in small cells again.

Treatment free feral bees

Up till now anyway, this colony of bees (and their ancestors forming this colony’s ancestor colonies) that has lived in a wall since several colony generations, has never been treated with any kind of chemicals ever, against Varroa mites or anything else.

June 29 last year I caught a swarm that came from this wall in a non-heated old house. (http://www.elgon.es/diary/?p=515) Towards the outside of the wall from the bees they had no insulation whatsoever. Just a thin board of wood. At the inside though a thick log wall.

For a couple of years there’s been an Elgon apiary 3 km away (2 miles). But the bee colony has been longer than that in the wall. Further back in time the closest apiary was 6 km (4 miles) away. At that time the Varroa mite had not arrived to these bees. For many years this colony has swarmed every year.

The swarm I caught was not big, but it had an egglaying queen and built up strength well enough to winter safely. To help it make a lot of brood I provided it with a shallow super above an excluder. I shouldn’t have done that I think as it was too easy for me to just take away this honey super when it was time to prepare the colony for winter. That is stressful time.

Now the bees hadn’t much honey left so I gave them 20 kg (44 pounds) of sugar in sucrose solution. If I hadn’t taken the small amount of honey it would have had about 10 kg (22 pounds) of honey for winter storage. Seeing how the colony behaved I think it would have made it well through winter with that amount. My first colony ever in 1974 had about that amount its first winter.

I saw no wingless bees during the season last year, so they got no Thymol against mites. I didn’t then have any quick way to measure the mite population (but here is at least one: http://www.elgon.es/diary/?p=354) And as I mentioned it was stressful times for me.

The queen stopped laying entirely in late summer. In November I saw through the plastic sheet used as kind of inner cover that the bees was sitting tight together like vacuum-packed peanuts.

FeralWIntered

About 10 March this year when the bees had their main cleansing flight after winter the cluster had spread out and filled more room than in November. It was very few dead bees on the bottom board. And not one defecate spot at the entrance.

These bees seems at least to be more winter hardy and be more Varroa resistant than common beekeepers’ bees, which have not been selected for Varroa resistance.

 

A possible scenario

A swarm of Elgon bees flying from the Elgon beekeeper 6 km away finds the cavity in the wall. Varroa mites havn’t arrived yet to the area. No beekeeper robs the honey or exchanges it for sugar. The cavity is not bigger than maximum two big boxes a beekeeper uses. The amount of brood can’t be as big as in a beekeepers hive. And the restricted area makes the volume finally too small for the bees (no beekeeper puts on boxes) and they swarm, every year mostly. Insulation is almost none. No beekeeper renews the wax and the bees build what they want when it comes to for example cell sizes. The Elgon beekeeper used small cell size to begin with. Here the cell sizes may become still smaller due to cocoon residues.

The bees adapt to the new environment now when they are on their own, like they were before there were any beekeepers around. In this adaption process the epigenetic process is most important, at least at first. The different environment created by a different “hive”, different food (more natural) and different cell sizes (also still smaller) gives a different chemical environment of many aspects. For example the different cell sizes give somewhat different food for the larvae, amount and probably composition also. This results in switching off some genes and turning on others in the DNA. Disturbing chemicals like pesticides and treatments in the hive can hinder this epigenetic process. But not for this swarm. It lived in a non-farming area and no beekeeper put chemicals in their hive.

There were no neighbor bees. Thus no bad influences from non-resistant bees drifting into their hive and no reinvasion of mites.

When the Varroa mites arrived the drones that became “fathers” were those that the mites didn’t parasitize. Maybe they avoided those drone larvae. And also those drones that were parasitized but were not as affected as others, became “fathers”. Thus also an adaption for resistance took place with a change of the DNA. Natural selection thus took place.

As the colony swarms every year there is a break in the brood production. This hinders the reproduction of mites. Also there is both an epigenetic and a genetic adaption with the new generation.

The smaller cells give less attractive food for the mites. They get less fertile on larvae in smaller cells. http://www.elgon.es/diary/?p=596

Drone cells get smaller in colonies on smaller worker brood cells. With smaller worker brood cells you get worker bees that get more hygienic. http://medycynawet.edu.pl/index.php/component/content/article/336-summary-201412/5234-summary-med-weter-70-12-774-776-2014 or http://alturl.com/a8scb Small cell beekeepers, including me, reports a widespread occurrence of uncapping and chewing out of capped brood in both worker and drone brood parasitized by mites. http://www.elgon.es/diary/?p=544 But VSH is said sometimes to not occur on drone brood. But those bees are kept on large cells. At least it doesn’t occur as much in drone brood. But it is observed quite a lot sometimes in small cell colonies as mites are observed to be much more common there in drone brood than in worker brood. http://resistantbees.com/blog/?page_id=2471

 

What happen with feral bees in a beekeeper’s hive?

If a swarm from feral bees end up in a beekeeper’s hive with large cell size, the environment changes and a “reverted” epigenetic process takes place. If there are more bee colonies in the apiary or close by all bees will be drifting (as is common) in all colonies and be mixed more or less. If these other bees have no or very little resistance against Varroa they will have a negative impact on the more resistant feral bees. These were enough resistant in the wall. Are they enough resistant now in this beekeeper’s hive? Maybe not.

If the feral swarm ends up in a beekeeper’s hive with small cell size, and there are neighboring bees that have substantial resistance against the mite, it may be that this swarm will do very well fighting the mites. Especially if there are no or very few bees around that can’t make life miserable for Varroa mites.

What will happen with my feral bees? Will they continue to be treatment free?

Understanding history

The first commercially wax foundation, in USA 1876, produced by A.I. Root, had imprints for 5 cells per inch for worker cells, a little less than 5.1 mm cell size. That was said to be an average of cell sizes found in a bee colony.1

Nowhere in the bee literature you could find notes that the smaller sizes mostly were used for brood and the larger mostly for honey storage. It seems this fact was not discussed. That means that you can’t be sure how well the measurements are made that constitute the ground for figures of cell sizes in the bee literature, even up to our days. To be sure to what extent you can trust figures given you need information how many and where in the nest samples are taken. Best is to get the range, smallest and biggest sizes found as well. And after foundation has been common you need to know if the combs are built with foundation or not. If the measurements are taken from combs built without wax foundation, you need to know if the bees have come from a beekeepers hive or from feral bees since several generations (with new built brood combs without foundation every year or so). The latest are the only really trustworthy to get an idea of the natural cell sizes.

In the beginning of the 20th century in USA beekeepers many times found that bees did a better job drawing foundation with somewhat larger cell size, about 5.2 mm. That’s easy understood as foundation mostly were drawn in the honey supers when the honey flow was good. Under such conditions bees want bigger cell sizes, honey storage cells. Brood sized cells they draw best in the broodnest early in the season before a strong honeyflow. And those smaller bees before the time of foundation that were born in smaller cell sizes than the average of 5.1 mm were now no longer born and could not help to build smaller cells.2

The beginning of wax foundation

When beekeepers began to experiment making wax foundation, they had to decide which size of the cell imprints they should use. Of course measurements took place. Evidently they found different sizes as the first molds and mills for foundation differed quite a lot concerning cell size. Some kind of reasoning must have taken place before they decided which sizes to use.

With bigger sizes it was easier to extract the honey and less wax was used by the bees, thus they were quicker to build. Probably one of the reasons bees themselves want bigger sizes in the honey storage area.

When large sizes were used in the brood area the bees got bigger and their honey stomach as well. Many thought that such bees must be able to collect more honey. But there is no good designed test with many colonies over more than one season that give advantages for bigger bees. But many express their belief in bigger honey yields in the old literature. The arguments are longer tounges and bigger honey stomachs with enlarged bees. Roy Grout in USA saw no difference.3 The Belgian beekeeper Usmar Baudoux has been best known for working for an enlargement of the cell size to 5.7mm. The only argument he gives for a better honey yield is an invitation for beekeepers to come and see his bees.4

Constantin Antonescu from Romania experimented in 1954-1958 with a few colonies on two different enlarged cell sizes, 5.4 and 5.65mm, and meant that he could show a bigger honey yield from the largest cell size. But the information about the test is not sufficient.5

Those that wanted small sizes did so because they thought it was better to get as many bees as possible from a given comb area. In Belgium 5.0mm was introduced in 18916 and well accepted. Baudoux reacted against this and worked for enlarging the cell size.

In Switzerland there was even a mold made with cell size 4.55 mm.7 In 1857 Johannes Mehring made a mold with cell size 5.55 mm.8

Natural cell sizes

To find out which cell sizes are natural for Apis mellifera it would be best to be able to find good data before wax foundation became common. And the data should include many measurements giving a range of cell sizes. The best would also be to know if the samples were taken from different parts of the nest, from the core of the brood nest and from the outer frames. From where in the nest samples and combs have been taken I havn’t been able to find any notes of. But there are good presentations of data by Jeffries Wyman (1866) and Thomas Cowan (1890). Also there are some interesting observations given in a paper by Hugo Gontarski (1935).

Jeffries_Wyman2  Jeffries Wyman, Professor of Anatomy at Harvard College 1847-1874. (Foto: Wikipedia)

Jeffries Wyman

Jeffries Wyman was Hersey Professor of Anatomy at Harvard College (1847-1874), president of the American Association for the Advancement of Science (AAAS) in 1858. He wrote 70 scientific papers and was well respected by fellow scientists on both sides of the Atlantic.

Wyman reacted on the claims of Maraldi, Lord Brougham, Koenig and other mathematicians that the cells of the bees were perfect, made in accordance to theoretical perfect execution in terms of material consumption and strength. He writes that the best observers like Reaumur, Hunter, the Hubers and others had noticed irregularities, but that they were occupied of clearing up other points relating to the habits of the bee. The irregularities of the cells were passed by, for the most part, with merely a mention.

Wyman in an article for the University described the irregularities of the cells, Notes on the cells of the bee (1866).9 One irregularity is the different cell sizes. He first states that the average size is one fifth of an inch [5.08 mm]. The same says Reaumur and Huber, even if their inch, the French is about 5% bigger [5.33 mm]. But they don’t present any measurements like Wyman does

Cell measurement X2 Wyman did three parts (part measurements) like this for each measurement. Three such measurements (with three parts) on each of the four combs measured.

Wyman did three measurements on four different combs, which all were “in all respects god average specimens”. Each measurement was done in three parts. Each part measured ten cells in a row. The second part crossed the first with one of the the middle cells included in the first. The same goes for the third part, which also had the same middle cell as the other two measurements part. So each part was a measurements over ten cells and all three had the same middle cell. The first one parallel to the top list. The other two then in angles to the first forming kind of an X for all three parts. Three such measurements with three parts were done on each of the four combs.

The smallest average for ten cells was 1.85 inch [4.7 mm for one cell]. Note that the 4.7 mm for one cell here is an average. That means that some cells were smaller and some were bigger. So the smallest size was smaller than 4.7 mm.

The biggest average for ten cells was 2.10 inch [5.33 mm for one cell]. Note that the 5.33 mm for one cell here is also an average of ten cells. That means that some cells were bigger than 5.33 mm. The real range of cell sizes thus was bigger than 4.7-5.33. But on the other hand one singular cell was probably not regular in being smaller than 4.7, or bigger than 5.33, so I think we can go with the range 4.7-5.33 for actual cell sizes. The average of all measurement parts (36) is 2.01 inch [5.11 mm for one cell].

I din’t know of the sizes Wymann found until recently. Wymann is cited sometimes, but not his findings very often. Why? He is after all a very well merited scientist. His measurements are the best done before the times of wax foundation, the most trustworthy because of the way he did them.

Thomas W. Cowan

Cowan founded the Beekeepers’ Association in Great Britain with Charles Nash Abbott in 1874. He designed the cylindrical honey extractor. He was the editor of the British Bee Journal and the Bee Keepers’ Record. Cowan authored books on beekeeping and related topics and was a collector of beekeeping books.

In 1890 he published the book The Honey Bee: Its Natural History, Anatomy, And Physiology.10 On pages 179-182 he deals with the sizes of cells, citing also Jeffries Wyman. Cowan had examined combs from black bees in England, Italian bees in Italy and of Carniolian bees in Switzerland, also of various bees in Canada and USA. The summary is an average of 5 worker cells to the inch.

He made a test similar to that of Jeffries Wyman with a total of 36 measurements as Wyman did. His least average of ten cells was 1.86 inch [4.72 mm for one cell]. His biggest average was 2.11 inch [5.36 mm for one cell]. He also found that “…, generally speaking, the cells increase in size towards the ends [of a comb], although this is not invariably the case”.

Hugo Gontarski

Hugo Gontarski was the first leader of Das Institut für Bienenkunde in Oberursel, Germany, 1938, where he started a lot of reaserch. In 1935 he published a paper about cellsizes in Journal of Comparative Physiology,11 – Wabenzellmasze bei Apis Mellifica.

He wanted to see how bees built combs without the help of wax foundation. So he made new colonies with frames without foundation. The bees came from colonies with combs built with foundation with cell size 5.44 mm, 5.68 mm and 5.74 mm respectively. 5.44 Gontarski called normal foundation.

“In all cases though were the newly built worker cells smaller than the brood cells in which the bees who built them were born.” (page 686)

This is also the experience of beekeepers today that want to take down their bees in cell size. After a couple of months all combs can be taken away from the bees again and only empty frames without foundation given. Once again the bees will build smaller cell size – and again and again, until they reach the sizes of their genetic disposition. So what Gontarski got with this test was not natural cell sizes, but the first step down in finding out the natural cell sizes. The bees Gontarski used had apparently a genetic disposition for cell sizes well smaller than 5.44mm.

Gontarski also tried some foundation with very large cell size and some with 4.71mm cell size, to test the limits of the plasticity of the bee’s ability to build different sizes of cells. (Actually it is not possible to find out that in one step like he did here.)

An interesting fact is that his bees born in 5.44mm cells drew 4.71mm cell size nicely. There’s a photo of such a comb on page 693. That would be very rare among European bees today. The genetic disposition for cell sizes in his bees must therefore have been for smaller cell sizes than what is common in Europe today.

Notes and references

  1. Root, A.I., ABC of Bee Culture, 2nd edition, 1884, page 146: ”The worker-comb measures very nearly five cells to the inch, on an average [emphasis added]. … The best specimens of true worker-comb, generally contain 5 cells within the space of an inch, and therefore this measure has been adopted for the comb foundation. (Comment 38 at the end of the book, comments made by G.M. Doolittle in 1880 to the first edition of this book reads: MAKING USE OF LARGE CELLS. We tried to so improve the bee as to make them take cells 4½ to the inch [5.64mm], but we had to give it up, and believe God knew best when he taught them that five is right.
  2. In Gleanings of Bee Culture in 1938 E.R. Root argued for 5.2 mm cell size, not smaller and not bigger as, in line with Frank Cheshire in England 1888, not to get the bees “out of tune with nature”. Cheshire though argued for 5.1 m cell size – Cheshire, Frank R., Bees & bee-keeping : scientific and practical”, L Upcot Gill (1886-1888), part 1, p 176, part 2, pages 315-318
  3. Grout, Roy A., Influence of Size of Brood Cell Upon the Size of the Worker Bee, American Bee Journal, April 1936: “… we must consider the fact that the crucial test for the commercial use of enlarged foundation is greater honey production. While this experiment should be a strong indication toward that end, the exact relation of this increase in the size of the adult worker bees to a greater yield of honey has yet to be proved. During the past four years, we have been conducting an experiment in a commercial yard with from fifteen to twenty colonies containing brood combs constructed from each size of foundation [5.2mm, 5.5mm and 5.7mm], making an apiary of sixty colonies maximum. To date we have not been able to find any significant increase in the honey production due to usage of enlarged cell foundation.”
  4. Baudoux, U., The Influence of Cell Size, The Bee World, Vol. XIV, no 4, April 1933, p 41: ”For those who are not convinced, Tervueren is always there.”
  5. Antonescue,, The Efficiency of the Use of Enlarged Cells, XX Jubilee Apimondia Congress, August, 1965, pp. 675-677. The variation of figures for the different colonies were not presented, just averages, so no statistical significance could be calculated. The strenght of the different colonies were not presented. No info of the heritage of the queens in the colonies were given, with so few colonies a group of sisters is a must. The text is online here: http://resistantbees.com/blog/?page_id=1254
  6. Baudoux, U., The Influence of Cell Size, The Bee World, Vol. XIV, no 4, April 1933, p 38: ”About 1891, foundatin with cells 920 to the sq. Dm. [5.0 mm] was introduced into our country. Beekeepers all adopted this size of cell. The experts of that time believed that it was advantageous to produce as many bees as possible on the least possible surface of comb.” My calculations to mm translations are made with the formula: X=100÷√(A÷2.315), where X=cellsize in mm and A=cells/dm2. Control the formula with: A=23150÷X2
  7. Zander, Enoch, Die Zucht der Biene, Neue bearbeitete Auflage, 1941. Verlag von Eugen Ulmer in Stuttgart, page 236: ”Um 1860 stellte dann der Schweizer Graberg aus unverständlichen Gründen Pressen mit 835 [5.27mm] Zellen her; es gab sogar solche mit 1120 [4.55mm] Zellen.”
  8. Zander, Enoch, Die Zucht der Biene, Neue bearbeitete Auflage, 1941. Verlag von Eugen Ulmer in Stuttgart, page 236: ”… die ersten Mittelwandformen von Mehring 748-750 Zellen je 1 qdcm ausweisen.“
  9. Wyman, Jeffries, Notes on the Cells of the Bee (1866), Cambridge: Welch, Bigelow, and Company, Printed to the University. From the Proccedings of the American Academy of Arts and Science, Vol. VII, January 9, 1866. Reprinted for sale today by Kessinger Legacy Reprints: http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Dstripbooks&field-keywords=Notes+on+the+cells+of+the+bee (short url: http://alturl.com/p6fgr) Downloadable pdf-file from this website: http://www.jstor.org/stable/20179545?seq=1#page_scan_tab_contents (short url: http://alturl.com/8jejf)
  10. Cowan, Thomas W., The Honey Bee: Its Natural History, Anatomy, And Physiology, London: Houlston & Sons (1890). The book can be read online here: http://babel.hathitrust.org/cgi/pt?id=wu.89094199411;view=1up;seq=10 (short url: http://alturl.com/eetaj)
  11. Journal of Comparative Physiology A- Neuroethology, Sensory, Neural, and Behavioral Physiology, 21, (5) 1935, Hugo Gontarski – Wabenzellmasze bei Apis mellifica. It can be downloaded as a pdf-file from this website: http://booksc.org/book/5935244

 

Small cells and VSH

There have been numerous tests of varroa reproduction with bees on different cellsizes throughout the years, with the assumption that you then test varroa resistance. As far as I understand that can be true, but you don’t know to what degree it is true. One thing is clear – testing varroa reproduction is focusing on mite behavior, not on bee behvaiour. Bee behavior is for example VSH (http://www.elgon.es/diary/?p=146).

VSHtest-14 VSH test in 2014. I use a reading glass with lens lamp plus a pair of reading glasses 2.5+ and tweezers.

Leaving out bee behavior when trying to understand varroa resistance is not a good choice. But mite reproduction is also interesting if you want to get full understanding of Varroa resistance. For the practical beekeeper though the easiest is to focus on VSH, maybe measuring mite population once or twice a year (http://www.elgon.es/diary/?p=354) (http://www.elgon.es/diary/?p=365) and listening to nature to get the fittest kind of bees, using small cells at least in the brood nest (http://www.elgon.es/diary/?p=224) (http://www.elgon.es/diary/?p=119).

What about mite reproduction in small cells? At first when mites arrive in an area, mites reproduce well enough to grow very big mite populations, also in colonies with small cells, in South America and in South Africa – and with me. But after 5-6 years the bees have developed what is recognized as mite resistance. Maybe with me too soon, this is the fifth year and I have seen very promising results.

The best reproduction test

The best test on mite population growth in different cell sizes I find “Brood cell size of Apis mellifera modifies the reproductive behavior of Varroa destructor”, by Matı´as Maggi, Natalia Damiani, Sergio Ruffinengo, David De Jong, Judith Principal and Martı´n Eguaras in Exp Appl Acarol (2010) 50:269–279 (http://www.ncbi.nlm.nih.gov/pubmed/19768560).

It’s a test under natural conditions, not a designed test. The scientists have collected data during a natural condition, well, a natural beekeepers condition of today. But they didn’t treat for varroa the 18 months before the data collection to have an enough big varroa population to get reliable data. I think the paper is interesting enough for anyone interested to buy the full text. It contains a good discussion, which reveals a lot of knowledge on the subject.

The test confirms other tests showing that Varroa mites prefer bigger cells. This test also shows that the distribution of mites in the brood with different sizes of cells is in line with that preference, the smaller the cell size the less probability that the cell is infested with a mite.

SC Maggi

But what then if there are only small cells in a brood nest – would the Varroa population grow at the same rate as if there were only large cells. That’s the really interesting question to get an answer to. That’s not what this test tried to get an answer to. But there is an interesting discussion in it.

They took a capped brood frame from a number of colonies, uncapped all brood and registered and measured all cells with mites. When a colony in this test had a comb with different cell sizes the reason was that it was such an old comb that the bees had reworked the comb with patches of smaller cell sizes. Also old combs had smaller cell sizes due to a lot of cocoon residues. Some of the brood combs tested came from combs relatively newly drawn from foundation with 5.4 mm cell size imprint (personal information).

The colonies had a mite infestation between 16 and 63 % in the worker brood. So the group of colonies did not form a resistant stock. The more resistant colonies (with lower infestation) would have big problems with reinfestation from more susceptible ones if all were left untreated in the same apiary.

Why do mites avoid smaller cells?

Why did mites avoid cells with smaller size? Probably because they and their daughters will become infertile quicker in those. Last sentence in the abstract:

“Infertile mother mites were more frequent in narrower brood cells.”

There is a discussion why this is so. A probable answer is the food for the mites. They feed on larvae and pupae and bees. Larvae in smaller cells get different food, the phenotype becomes different. This is a logical explanation why mites are more attracted to larvae in bigger cells. The food is tasting better there and is more nourishing for the mites giving them a longer and more fertile life.

Yves Le Conte

In a lecture in Versaille in France 2006 on the SICAMM conference, the association for breeding the dark honeybee Mellifera mellifera, Yves Le Conte showed the graph on the picture here, taken by a Swiss beekeeper attending. The graph shows results from tests LeConte had done (most probably involving the varroa resistant feral stock he is working with), showing a decrease in fertility for mites in cells with smaller volume.

SC Le Conte Varroa cellsize

This is almost the same as saying cells with smaller cell size. It’s just adding the depth of the cell to the bottom area (“cell size”, mm between the parallel sides of the cell, is a way of presenting the bottom area of the cell). Maybe this also indicates that the distance between the combs might influence if it’s narrow enough to give shorter cells.  If the distance between the combs are bigger than necessary the depth of the cell will though not be bigger. The space to the other comb will though be bigger if on that side there is brood as well. The results of Le Conte and Maggi et. al. are confirming each other.

“Infertile mother mites were more frequent in narrower brood cells.”

Mites don’t lay eggs forever. After a number of rounds in capped brood cells laying eggs (about three normally) their fertility is over. Next time they enter a brood cell they are infertile, lay no eggs.

Fewer rounds in smaller cells you might well don’t see in a short test, all those tests from two and a half month to a year that have been done. Especially if large cell control colonies are close by sharing their mites, more the higher the mite population grow.

In an area with only small colonies then, why did the mites develop at all so heavily, in the beginning few years (with no or relatively little treatment)? Good question. Evidently some kind of adaption to the presence of mites had to take place. It seems the bees had to learn how to chase the mites. They developed better hygienic type of behavior against the mite, both a general reaction against mite infested brood and a more specialized like VSH (where only mites with offspring are cleaned out of brood). On top of that genetic selection that favor these behaviours.

When queens from resistant feral bees from France were tested in Canada against “native” stock the result showed no difference. The queens were introduced in bee colonies that hadn’t learned how to deal with the mite because the mite pressure was in general to low, the bees were on large cells, the control colonies were to close to the test colonies sharing mites and the test period was too short.

Could some of the VSH-result obtained in small cell bees be caused of or explained by the small cells? Are the small cells helping the bees and the beekeeper finding the VSH trait in the selection process? Will good VSH queens on small cells not give so good VSH bees on large cells? Or to put this another way.

Do small cells contribute in expressing the VSH trait through making the mites infertile quicker? The results of Yves Le Conte and Maggie et.al. indicate that.

Are the more phenotypic changes from small cells that have impact on resistance against varroa and viruses?

Swarm from a tree

Vildbiträd2

Last year my friend had a call in July about a swarm that had come from a big old tree. The cavity couldn’t bee very big. And the swarm was not big. http://www.elgon.es/diary/?p=235

But the bees in the tree survived the winter and was thriving this year too.

The swarm was last year strengthened with a couple of brood frames from his other colonies. It was not treated against varroa last year. It survived winter well. This year it was used as his other colonies to produce splits for sale. A couple of weeks ago he was too curious about the amount of mites in the colony so he gave it 15 grams of thymol and collected the downfall. After a week 150 mites. Under the circumstamces it’s not much at all. The bees must have some kind of trait that keeps down the number. He has had thousands of mites falling in a few odd colonies in earlier years with such a treatment – as comparison. Normally he just give his colonies 15 grams of thymol, but in the middle of August. As the only treatment in a year. He has Elgon bees and uses 4.9 mm cellsize. His winterlosses is always below 5%.

Next year he plans to breed from this colony as it is a very nice one.