Resistance traits – VSH, VSHD, Grooming and more

Sometimes, the term VSH is used as meaning the same thing as varroa resistance. I think it’s helpful to clarify what VSH is. It is one of several resistance characteristics that affect the bees’ resistance to the Varroa mite.

VSH is not the same as uncapping capped brood cells with varroa inside and remove the pupae. It is one of a few different varieties of cleaning varroa invaded brood cells.

– VSH is opening (+ possible recapping, and / or + possible removing the pupae) of capped workerbee brood cells (not dronebrood cells) in which one or more varroa mites have entered AND the presence of offspring (children) to this (these) varroa mite(s) in these cells.

 VSH

As we see from the description here there could be different varieties of this trait. It isn’t needed that the bees remove the pupa for this behavior to de called VSH. It is enough that they uncap pupae with invaded mites with offspring. The bees may well recap it again. Uncapping is enough to disturb the reproduction of the mite. Is this difference in behaviour (recapping the cell and not removing the pupa) due to genetic difference?

– Uncapping and cleaning of capped workersbrood cells with varroa which have no descendants is not VSH.

– Uncapping and cleaning of dronebrood with varroa is not VSH. (But this is though also a valuable feature.)

– Other properties like grooming (removal and biting of mites from the body of other bees or themselves is an important feature, especially if the colony is reinvaded by mites.

– Resistance to viruses, for example in the form of good production of suitable peptides (short amino acid strings) which “eat” viruses is important.

– Reduced inclination for robbery is not VSH, but is a good feature, as it means less risk for reinvading/reinvasion of mites from bee colonies with increased varroa level and as a consequence thereof a reduced defense against robbery.

– Good defense at the entrance not letting foreign bees enter the hive prevents bees with mites on them from other colonies to raise the varroa level..

– Bees that return to their own hive and not to the neighbor’s (drifting) is an important feature to prevent the spread of mites within the apiary.

– Forcing virus infected bees to leave the hive is one way for the hive to get rid of viruses, it’s not VSH, still very good. The house cleaning bees treat virus infects bees like trash, bees with damaged wings (DWV) or worker bees hatched too early (grey bees crawling around, APV-types).

– There are I’m sure more traits that are important for resistance.

 

VSH is a good feature!

VSH can sometimes be confused with less good development for a bee colony. This depends most often on a queen not laying eggs very well. But if a VSH colony is getting a lot of mites through reinvasion from colonies with high varroa levels in the neighborhood (within a distance of 2 km/1.5 miles) the result may be a lot of shotgun pattern brood combs due to a lot of uncapped and cleaned brood cells to get rid of mites. The consequence will be a slower development of the colony. But as mentioned above a true VSH trait give room for the variety that the pupae are not removed but they are recapped after uncapping. And this can happen more than once. In such a case the consequence needn’t be slow development of the colony even if the varroa level temporarily is a bit high.

This is a good example of VSHD. You see clearly that pupae in drone brood are removed as brown cocoon residues are left. This is the first round with brood. Also we see uncapped drone pupae with purple eyes, and some cells with uncapping having started with holes in the capping. Click on the pictures to make it bigger

 

 More acronyms

Perhaps it’s good if more short names, such as acronyms as VSH, become common, names for different characteristics of resistance.

– With regard to the concept of Grooming, This term is well established. Bees have mites on their body and these are removed by other bees or themselves. We need no other term here.

– As far as VSH on drone is concerned, it is quite newly discovered and no special acronym is used as far as I know. VSHD = Varroa Sensitive Hygiene Drones.

That’s an important feature, maybe more important than VSH. The acronym VSHD could work well.

The mites are more attracted to dronebrood than to workerbrood. If a colony has 5-10% dronebrood in the brood area, as is often found in feral colonies (at least) and bees have a strong VSHD, the bee colony will not lose so many worker pupea (future valuable worker bees). Many mites will invade drone brood and will be cleaned out from this drone brood.

The Norwegian Hans-Otto Johnsen has shown (he is conducting such surveys and there is some notes about this in Norwegian bee magazine Birøkteren and on this blog) that bees more easily identifie mites in smaller dronebrood cells (6.2 mm) than in larger (7.2 mm), and clean out them from mites and pupae. Bees make smaller dronebrood cells naturally, the smaller the cell size is for workerbee cells. This is probably an important characteristic that small cell size provide. The drone cellsize is naturally 6.2-6.4 mm when the bees live on 4.9 mm worker bee cells.

These acronyms may work

ED  for entrance defense.

LR  for low robbery.

LD  low drifting.

VP  for virus peptides.

VB  for trashing virus infected bees

– If you have suggestions or comments don’t hesitate to share them, for example concerning more resistant traits. Maybe you have ideas how to measure resistance traits? Maybe the best selective tool is just measuring the varroa level a few times a year?

Keeping track of the infestation level

In the search for breeders for this season I tested a number of hives for the infestation level of Varroa mites in the beginning of May. Those choosen had not been treated for mites either not at all last season, or very little with thymol in the spring last year after showing an odd wingless bee. This was before the time of the Beeshaker with me. Better hade been to use the Beeshaker before using thymol to really know the infestation level.

I used the Beeshaker (more info about it and how to use it: http://www.elgon.es/diary/?cat=85). There were colonies with 0 mites from somewhat more than 300 bees. The best of those I use as breeders this year.

I also gave a number of colonies a thin tray with a coarse mesh that bees couldn’t pass hrough. High enough from the bottom of the tray so the bees couldn’t clean the tray. It covered almost the entire bottom. The purpose was to collect natural downfall of mites over a period of time.

I send some queens abroad and the Board of agriculture wants to be sure I have no tropilaelaps mites and no small hive beetles. (Both of those two pests have not been found in Sweden, tropilaelaps not even in Europe, the small hive beetle only in Italy.) Three weeks before the veterinary and the bee inspector came to visit for checking my bees I inserted these thin trays. Of course the inspector and vet also checked for American foul brood.

Varroagaller Varroa trays for checking natural downfall of mites. The one to the left without mesh cover.

Two of those hives I had checked with the Beeshaker got a tray. Three weeks later one of them had 7 mites on the tray. The other had 8. The bee shaker had given 1 mite each for these two hives.

1 mite per 300 bees is 0.3% infestation level on the bees (not counting the mites in the brood, those are usually at least the double amount).

Let’s say I missed 2-3 mites of the natural downfall. That would then be 10 mites in let’s say 20 days for easy math. That gives 0.5 mite per day. It’s been said that natural downfall per day during the brood season multiplied by 120 gives about the total number of mites in the colony. That would make 60 mites in total in those two colonies. The number of bees in those colonies were more than 30,000 each. But let’s say it was 30,000. If we divide 60 by 30,000 we get an infestation level of 0.2%. This level is though including the mites that had been in the brood during these 20 days, so the figure is not directly comparable with the 0.3% to confirm that the two methods give about the same result. The estimation of multiplying with 120 and other uncertainties makes comparison and/or the methods not exact anyway.

Does this comparison give an indication that these methods are good enough for checking the varroa infestation? Both methods have been used by others to decide when to treat or as a selection help for varroa resistance.

When the infestation level is so low as given above, it’s not possible to check the VSH trait either, as you will find too few pupae with mites. You can ask yourself if it’s at all necessary to test for mites anymore. I agree. But all my hives are not as good as these and reinfestation occurs. So I think I have to keep track in some way. Not in first place I think to find the best ones, but to find the ones with most varroa so I can protect the others from reinfestation.

The perfect resistant colony is of course such a one that is not very much affected by reinfestation, not letting in bees with mites on them for example. I will test colonies in August as well and I will check the hard boards in front of the hives for crippled wing bees or grey young bees crawling around as indications for viruses following to high varroa infestation.

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!

Treatment select for increased reproduction rate

Varroa mites multiply in bee larvae. After they come out of the cell when the bee is fully formed, they sit on the adult bees and suck hemolymph.

It was observed many years ago that during the brood period of the bees, 2/3 of the mites was found in the capped bee brood cells while 1/3 was on the bees.

VarroaBin2 Varroa mites on bees. Many years ago 1/3 of the mites were sitting on bees while 2/3 was found in the capped brood. Today this has changed to 15% and 85%. (Photo: Anders Berg)

If the mites had been sitting longer time on the bees than they did, before they returned into a brood cell, a greater proportion than 1/3 had been found on the bees. If they had been sitting less time there would have been a smaller proportion found on adult bees. The shorter the time the varroa mites are sitting on adult bees, the faster they return into a new brood cell to reproduce. This would increase the speed of varroa reproduction in the bee colony.

It is thus from the beekeeper’s and the bee colony’s point of view desirable that the mites are sitting as long as possible on the bees, resulting in a slower development of the varroa population. So, if the proportion of mites had been ½ on the bees and ½ in capped brood, this would have been better than that found for a number of years ago when varroa mites had arrived.

In early December 2015, two professional beekeepers from the Spanish mainland came to the small island of La Palma, one of the Canary Islands, and lectured on the varroa problem (http://archiv.resistantbees.com/phoretische-varroen). One of them was Manuel Izquierdo Garcia, a biologist at the University of Seville. (Thanks Rüdiger Dietrich who drew my attention to this.)

30 years ago when varroa mites came to Spain, the proportion of mites on the bees was 1/3 and 2/3 in capped brood. During the past 30 years, the mites’ behavior have changed. You could say that during the 30 years of conventional treatment of bees to kill mites, the mites have responded by spending less time on the bees to accelerate their reproduction rate. They have also changed the place on the bees they usually sit, from the abdomen to the middle part of the bee.

The result of this change has resulted in 15% are found on the bees (previously 33%) and 85% in the capped brood (previously 66%).

VarroaYngel2 Mites are sitting shorter time on the adult bees. Thus you find at a given time 15% of the mites on the bees today and 85 % in the brood. This have increased the reproduction rate of the varroa population.

Increased treatment

This change has consequences for beekeeping. It explains why we in Europe have had to increase treatment to kill mites. There are examples of recommendations in several countries where the fight starts in spring and continues throughout the season. And anyway, or should one say, maybe sometimes also because of this, the bees have difficulties to survive.

Powdered sugar

Some types of treatment will also be less effective due to this change. Treating with powdered sugar, only kills the mites sitting on the bees. One must fight very often if powdered sugar should have any effect of relevance.

Oxalic acid

If there are still small areas of capped brood when one uses oxalic acid against the mites, the oxalic woun’t have the effect one wants. This becomes more relevant when climate change means warmer winters, as it will be more common with brood in winter times, the time when oxalic usually are used. It becomes even more important keeping bees that really have brood-free periods during winter, also for treatment free beekeepers.

Treatment is a dead end

It is becoming increasingly clear that it is a dead end using all kinds of chemicals against varroa mites. And it is with the increased reproduction rate of the mites more difficult to select resistant bees and get areas with treatment free bees – which is the solution.

Focus on varroa resistance

All this show how important it is to focus on producing as varroa resistant bees as possible and develop management methods without chemicals. It is important that all beekeepers understand the problem and are involved at least somewhat.

Every beekeeper can at least try to identify which of his or her bee colonies are the least good in resisting varroa mites and replace the queen(s) in those. The simplest way is to just remove the queen in such a colony and let the bees rear a new of their own. It is not the best method, but a start. Then you can make more steps in improving your bees, depending on interest and opportunities.

Aiming for a new season

In the beginning of March the bees had their main cleansing flight after winter. In the beginning of April most of them had more combs and boxes given. At the end of April another round checking food, need for thymol, collecting some dead outs and putting on supers took place.

Previous years winter losses were about 15 % with another 30 % were saved through thymol and queens shifted (no or little crop), This is the investment price for developing a more varroa resistant stock. I give some thymol when I see wingless bees.

Last year winterlosses were about 10 %. This winter losses are also about 10 %. A good development is that only another 10 % are saved with thymol and will have their queens shifted later. Also breeders have been treatmentfree longer and VSH value for the breeders are better. And bees are putting more honey closer to the broodnest for winter storage, thus there is more honey for winter food. The bees are shutting down brood already in August and waiting till January or February before starting again. Thus they use less food in winter and save it for brood when starting the new season, which is started even somewhat before the main cleansing flight. The bees know what’s coming.

Most colonies got a super above queen excluder in late April and those splits wintering on two boxes their third brood box. And those 10 % fighting varroa and virus and/or something else maybe a few drawn empty frames, some food frames and maybe a piece of dish cloth with thymol (4-5 gram).

Bästa samhället 2015-04w

The best colony so far

The best colony in April was the best producer last year, didn’t need any thymol last year, didn’t swarm and has a very good temper. It was wintered with 20 kg (44 pound) honey and 10 kg (22 pound) of sucrose sugar.

In beginning of April it had about 10 kg of food left and was full of bees. For safety reasons so the queen shouldn’t stop laying, it got a frame of food in the super from the storage.

In late April this box above the excluder was half full with willow honey and full of bees. So the colony got another super. I plan to check the infestation rate with the bee shaker (http://www.elgon.es/diary/?p=660) soon and also the VSH value (http://www.elgon.es/diary/?p=146). Of course I have to breed from it.

 

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?

The queen of the wall

Five days after I hived the swarm from the wall I checked it. I placed it about three km from the wall where it originated, to help form the ”stock of the region”. It wasn’t a very big swarm, but it will make it well for winter.

Swarm queenSwarm drone

It had placed itself on the foundations I had supplied them with and drawn quite some combs, partially filld them with honey and the queen had layed eggs in four or five shallows. A big queen, small drone and quite small workers.

Swarm house The bees have occupied the upper right corner and round the corner on the other side. There the original entrance was.

The wall colony is living in one of the upper corners of the house, for more than 10 years. Now the nearest other bees are 3 km away. 10 years ago 6-7 km.

Swarm propolis The entrance just below the window to the left. Below the bees have sealed cracks with propolis.

 

Three years ago the owners tried to tighten up the entrance between a couple of boards in the oyter wall of the house. After some time the bees had made a new entrance around the corner. Some cracks in the wall the bees have sealed with propolis.

Swarm entrance The bees are entering in the upper part of the opening and leaving at the bottom of it.

The bees enter the upper part of the entrance and leave from the lower part.

Honey for winter

In US I understand it’s more common than in Europe to let the bees keep honey for winter. On the other hand I’ve heard more and more beekeepers giving sugar for winter. And the discussion which sugar is the best for wintering. It seems sucrose is the best, from cane or beet. Of the sugars. The very best is of course honey. But is it, if sugar is much cheaper? And how is it, doesn’t honey produce a lot of residues filling up the guts and producing dysentery and bad overwintering? Yes it might, if you have bees making a lot of brood during winter, thus having to eat a lot. And without any possibility for cleansing flights.

In older times in Sweden honey was used a lot for wintering bees. In fact I saw a comment in an old beekeepers magazine that this particular year the autumn flow had been bad so the bees had had no opportunity to gather winter stores on the Heather. Heather honey today is said to create big problems for bees’s if overwintering on it. A tixotropic dark strong honey. In Sweden normally the bees are confined to the hive without any cleansing flight for at least five months.

What’s happened I think is that bees that brood too much in winter to be able to winter on difficult honeys are surviving because they have been wintered on sugar to the biggest part. We have weakened the bees and because of greed, thinking we are smart. It had been a better investment letting the bees keep enough honey for winter to make up at least the major part of the winter food.

Tobias Olofsson and Alejandra Vasquez have discovered many lactic acid bacteria are important for the health of bees. They live in the guts of bees and feed on nectar, honey and pollen, just as bees. They originate from other bee guts, not from flowers, but bees that visit flowers share these microbes that way too, besides directly in the hive to new generations.

They are continuing their research concerning overwintering on honey or sugar.

In an article in the Swedish journal Bitidningen Tobias is describing a new product for boosting bees with lactic acid bacteria. http://dmweb.v-tab.se/webpages/Bitidningen/bitid-13-0010.html, page 11-13. He is also describing a small test finding out what happened with the lactic acid bacteria when wintering on honey (2 colonies) and on sucros (2 colonies). The number of bacteria was much lower in the sugar colonies. These colonies used much more food, their colony strenght was much lower and they were irritated in temper.

Olofsson and Vaquez have produced a product they call SymBeeotic which is supposed to be used to boost a colony with low amount of lactic acid bacteria, for example after winter. But of course it’s better to leave enough honey in the colony for winter.

 

Plastic positioning and the mouse

You remember the previous post about the “multiple test”(MT)-colony, natural positioning, plastic frames, a mouse (or mice), mild winter and what a good condition this colony came out with now in spring. I’ve been thinking about it.

Mild winter

Yes the mild winter has contributed to the good condition. But what about varroa and viruses? Mild winter doesn’t help if you have too much of both in a colony. I would say maybe the contrary, or at least questionable. A lot of varroa triggers extensive brooding, to kind of replace the affected sick brood resulting in a bad rat race.

But less treatment

In fact one of the colonies in the apiary died during winter due to what looked like virus problems, in spite of some more treatment than the good colony got. And another colony which hadn’t received any treatment last year because it didn’t need it, it seemed, no DWV-bees, strong and healthy look – came out with fist size cluster and asking for survival until fresh pollen and steady temp around 60F (15C). We’ll see.

And this good colony got less Varroa treatment 2013 compared to 2012, actually half – at the most only a tenth compared to non-selected bees for Varroa resistance. With the same queen 2012 and 2013.

 Weaker varroa pressure

Now I think in spite of the dead colony and the one with the fistsize cluster, the average Varroa pressure, total amount of mites in the apiary, was less in 2013 compared to 2012. In fact I think this is the case in all my apiaries. Because I used in average about half the amount of thymol I used in 2012. This good colony I’m talking about specifically now got the average amount, 5 grams. Also, only 50% of the colonies going into winter had been treated during 2013, compared to 80% 2012. And, this spring winter die off will be less than 5% compared to more than 15% last spring.

The Varroa pressure I think is lower due to better Varroa resistance in average in my stock, also in this apiary. The least good ones are showing up every spring, either they die in spite of treatment, or they show up weak and get treatment and later their queens are shifted.

 Epigenetics and social learning

Also, from other beekeepers experiences, after about 5 years, mite pressure becomes weaker without any obvious reason. Probably some kind of epigenetic adaption (genes turned on and others turned off) is taking place that takes about 5 years from the first time the mites created problems. This spring is the fifth since the mites gave big problems the first time in all my apiaries.

This adaption to the presence of the mite and fighting it probably also involves social learning. Bees learning to handle the mite and pass this knowledge on to other bees in the hive (http://www.hindawi.com/journals/psyche/2013/768108/). Therefore it’s important not only to propagate good resistant bee colonies by making new queens from it, but also by making new bee colonies from it, including worker bees that can pass their knowledge to new generations of bees.

Plast49Yngel

 Uniform small cells

From the dead colonies through these diffcult years with Varroa I have harvested quite some badly drawn small cellsize combs. With too many patches of drone comb, and too many patches of bigger sometimes irregular “worker” cells. Good they have been culled.

These plastic frames with plastic foundation with cellsize about 4.95 from Mann Lake (http://www.elgon.es/diary/?p=119) that was used in the bigger part of the third (the uppermost) broodbox in the MT-colony at least didn’t have a big negative impact on the colony health. Plastic haters might draw such a conclusion right away. Now, I’m not a plastic lover. I don’t like using plastic. That’s because in general it isn’t degradable in nature. That’s what I want, degradable plastic. But here it is in our world and I tried it.

These plastic frames might even have contributed to the good health of the MT-colony. 10% more cells per comb, still quicker build up. No drone patches (BUT there should be drone patches here and there in the brood area to catch the mites that are there), no patches of bigger and irregular “worker” cells. No wavy combs (I use no wiring in my wax combs). No big bridges of hindrance of wood for the queen between brood boxes.

So I plan to try some more plastic frames from Mann Lake in brood boxes. But there should be a good balance between plastic and wooden frames as long as I will be using the plastic.

Europe versus USA: breeding varroa resistence

Rüdiger Dietrich’s comment is so good I made it into a post of its own as well. Thanks Rüdiger!

As a German I have of course to answer to Eriks contribution “Breeding for Varroa resistance: Germany versus USA”…:-).

When commenting about activities in the varroa resistance breeding area I guess it’s better to compare Europe versus US. Otherwise it would be too bad for Germany…

I think the main drawback for Europe compared to US is that a funded continuous breeding program is missing. The US seems to have at least 3 – Minnesota Hygienic Stock (MNHYG), Russian Honey Bee program (RHB) and VSH program, which all seem to have shown valuable outcomes. Moreover, the organic beekeeping community in the US, e.g. Ed and Dee Lusby, Michael Bush, Dennis Murrel and others have been innovative and could establish treatment free beekeeping since many years. And this could be achieved with local bee races or no complicated bee breeding scheme!!! Their impact with small cells, comb distance, not contaminated bee wax etc. is not only logic and inspiring, it works as stated above.

Europe did of course some funded scientific investigation of Varroa and could contribute to the understanding of infestation mechanism in the 90-ies, e.g. grooming behaviour (Bienefeld, Aumeier, Thakur etc.) or VSH (Rosenkranz, Vandame). However, efforts seem to be sporadic and as already mentioned not continuous, to yield in resistant queens that are distributed via the beekeeping community.

Besides, beekeeping organizations here I can only comment on Germany with the AgT (Arbeitsgemeinsschaft für Toleranzforschung) http://www.toleranzzucht.de/en/breeding-programme/, try to connect and coordinate different breeders in order to achieve bees that combine favourable and varroa resistant traits. However, improvement ratios seem to be small up to now.

But in my eyes Europe could contribute significantly by activities of bee breeders. The idea to use already varroa resistant bees for breeding was first established by Erik Österlund (1989) and John Keyfuss (1993), who cross African bees into A.mellifera mellifera/Buckfast. John uses a Tunisian bee (Apis mellifera intermissa) and Erik Apis mellifera monticola from Kenya. The resulting Elgon bee is since a bee that needs less or even no varroa treatment. The same is true for Kefuss bees and he gain merits by bringing this topic into broad public interest with his “World varroa challenge”.

This approach was copied by Rinderer (RHB), who used Russian bees that lived since 200-250 years with varroa mites and hence, should have developed resistance traits. The same idea was practically followed by P. Jungels (Buckfast – Primorski mixes) and J. Koller (pure Primorski) (Primorski synonyme for Russian bees) in Europe, who contributed significantly by providing varroatolerant queens to the European beekeepers.

A guy that use local (carneolian) bees for his breeding program is Alois Wallner from Austria http://www.voralpenhonig.at/, who has bred since 1990 for bees that groom and kill varroa mites by removing their legs. The result is now a bee that kill nearly every mite (varroa killer factor 100). Additionally his bees express VSH behaviour and hence, bees need only few or no treatment with formic acid.

In my opinion one brave European guy need to be mentioned as well which is Juhani Lunden in Finland http://www.saunalahti.fi/lunden/varroakertomus.htm He managed in a brute force approach to breed varroaresistant bees, which are not treated since 2009. He used a strong selective pressure to achieve his goal and hence, other traits as gentleness or honey crop might be compromised.

So taken together, these efforts need to put on a strong base in Europe as well and both, the spread of “resistant genes” by suitable queens and by suitable programs need to be pushed and furthermore the usage of organic beekeeping principles that result in treatment free bees should be distributed. That includes the courage of not using treatments to outselect non optimal strains. Here the community in Europe is already on the way see http://resistantbees.com/ (Germany and Spain), but Europe should definitely speed up and learn the positives from the US. This is especially true for the scientific sector and funded EC programs.