I have just returned home from the annual meeting of our local bee association. Susanna Kivling spoke about the Beescanning project, beescanning.com We were also discussing to establish an Elgon mating place for queens of the members. The best report I got after the meeting from Arne Andersson who got two queens from me last year of the line H131. He treats all his colonies every year for varroa. So he treated these two Elgon colonies with sublimating oxalic acid (“heat-steaming”) some time ago. He decided to treat them again with trickling oxalic sugar solution as he got so few mites from the treatment. These two treatments gave together two mites each from the two Elgon colonies. Another type of colony close to them dropped altogether 1000 mites. Cellsize? 5.1. I hope the Elgon colonies survives the two tough treatments so I can consider grafting from them next year.:)
Last year I saw more wingless bees than I had expected and I used more thymol than I had expected. I realized that I could partially thank the bad weather fort thias. The bees had got too little of pollen. Their immune system was not at its peak.
It was not easy to find suitable breeder queens, ie, who showed great varroa resistance. I found a colony that had not needed varroa treatment for a few years and it had not had any wingless bees. VSH test could not be done as I found only one mite in more than 100 pupae. And this mite had no offspring. So if you would allow it to determine the VSH-level, this would be 100% VSH. However, the so-called statistical significance was non-existent because of the low number of mites (just one single one). Well, the low number of mites were decisive. S241 was last year’s most important breeder colony.
This summer, I have not seen much of mites and almost no wingless bees so far. Some odd mites in 4 colonies, of more than 140 hives. Well, those who got the most thymol last year, got Thymol in May this year and then got its Queen replaced. So that’s one explanation, about 15 colonies. A colony that was a split from one of those 15, which raised a queen of their own was the first. Due to it’s history it got Thymol as soon as I saw the wingless bee. The queen will be shifted.
A problem hive had got a daughter of S241 last year. A Beeshaker test though showed 0% varroa level. Viruses still a problem in spite of no mites?
The other day I saw a wingless bee on the hard board in front of the entrance of a colony that had got a lot of Thymol last year. It did not get Thymol in May as it was shifting its queen in May, I found a dead virgin on the hard board and drew that conclusion. I decided to make a test with the Bee shaker due to the wingless bee. I did it yesterday, July 20, 19 mites out of minimum 300 bees , 6.3% varroa level. The hive got Thymol.
Today I came to an apiary with a daughter of the 241 (introduced in 2015) which have had no need for Varroa treatment in a couple of years, neither 2014 nor 2015. This colony was now a strong colony that given a good crop. With still some time to go for eventual more honey to come.
In May, I tested interesting candidates for being breeders with the Bee shaker. This 241-daughter was among those of course. The Varroa level was 2%. I didn’t give it Thymol as this was not more than 3%. I had several colonies, including several 241-daughters, that got only a few grams of thymol in spring 2015, which showed no mites at all (zero) out of more than 300 bees. The two best with different heritage (one was a 241-daughter) I used as breeders this year.
2% -colony I tested today July 21 regarding the Varroa level, 4 mites out of a little more than 300 bees. 1.3% infestation level. At least not higher Varroa level after 2.5 months. A strong hive that has given a good crop. The Varroa level would have been much higher if the bees could not get rid of mites themselves. This colony has thus been able to get rid of mites by themselves. What a great feeling!
Now this does probably not only depend on the queen. It was introduced to a colony that had not needed any treatment for at least a year. The worker bees might have learned the new queen’s bees some tricks how to deal with mites. It would not surprise me if there is a combination of reasons for the mite fighting ability of this colony. http://www.elgon.es/diary/?p=880 http://www.elgon.es/diary/?p=890
It has been discussed where to take the bees when making the test for infestation level of Varroa mites with the Bee Shaker. From a brood frame or just near the brood. The first week of May, I did a test with the Bee Shaker of a number of bee colonies. After that I inserted sticky boards to collect the natural downfall. This happened to coincide so that two colonies tested with the Bee Shaker also got sticky boards. The sample of bees for the Bee Shaker were taken from the middle of a the super just above the queen excluder.
A good compromise place to take the beesample from to the Bee Shaker is in the middle of the first super above the queen excluder. You don’t have to look for the queen. Not close to the entrance where the number of mites are fewer than average. And not far awav from the brood, when there are many honey supers. The number seems to vary more there.
Those colonies tested were choosen as I had found them to be potential breeders. The two colonies mentioned both had one (1) mite in the Bee Shaker out of about 350 bees, ie about 0.3% infestation level. Three weeks of natural downfall thereafter gave 7 mites from one and 8 from the other. The sticky boards covered almost the entire bottom. Let’s say I missed seeing two mites. If so it was thus about 0.5 mites per day.
Multiplying this figure with 120 I have heard gives a figure for the total number of mites in the colony. 0.5 x 120 = 60 mites in total then. The number of bees in the colonies were at least 30 000. But let’s say it was 30 000. Then 60/30000 would maybe give an infestation rate = 0.2%. But now I’ve seen reports that one should multiply by 30 (20-40). Then it will be completely different figures (in “favor” of the Bee Shaker). Collecting natural downfall should be done during the normal brood period, not in the very beginning or the very end of the brood season. In the case of the natural downfall of varroa mites, mites will also come from mites emerging from brood cells that have hatched during these three weeks. The natural downfall should therefore have given more mites compared with the Bee Shaker if these methods should have given corresponding figures. Therefore, the conclusion should be that the Bee Shaker revealed a greater proportion of the total number of mites in the hives than the natural downfall did.
The Bee Shaker could therefore be trusted to be an enough reliable tool to show infestation levels of Varroa mites, when samples are taken close to the brood, but not from brood frames. http://www.elgon.es/diary/?p=914
Before varroan came there could be seen occasional bees with undeveloped/deformed wings in spring. Maybe it was the influence of DWV, Deformed Wing Virus. But it may also have been chilled brood. During the final phase of the pupa development to finished bee the wings are formed. Cold nights and too much of brood could maybe have caused undeveloped wings.
Today, one can probably assume that when you see a wingless bee, it’s DWV responsible. Varroa mites are paving the way for many viruses into pupae and adult bees that had not previously bothered bees. Moreover, these viruses multiply in mites. So today mites spread viruses more efficiently than when the mite had just arrived in Europe. Why that is so is another interesting discussion that probably involves the use of miticides.
The Bee Shaker
The Bee Shaker is a great way to keep track of the level of mites in the bee colony, especially in spring and late summer, so the amount of virus can be kept reasonably low by allowing people to fight the mite if it exceeds a certain degree of infestation. (If that is the strategy chosen.) A good benchmark that many use today is 3%, three mites on one hundred bees (9 mites in 300 bees/1 deciliter of bees).
It also means that to develop a bee stock towards better varroa resistance, you don’t treat against the mite, especially below a mite level of 3%, whenever in the season it is measured.
But if there are wingless bees in the bee colony? It’s usually a sign of DWV and thus too many mites. Here is the Bee Shaker again a good tool, to find out if there really is a high degree of infestation of mites when you see a wingless bee. If you decide to treat against mites if the level is high you might do it to prevent the spread of mites to other colonies nearby.
A colony with a wingless bee
Last year’s breeder queens seem to have produced many queens that have given colonies that control the mites quite well. One of these daughter queens was introduced to a colony that had problems with mites. Perhaps the biggest problem was virus.
This colony was quite weak in this spring and developed slowly, compared to the other colonies in the apiary. I concluded that I would have to check the brood nest to find out the cause. Maybe the colony was shifting their queen?
On a later visit to the apiary about June 20, I saw one, only one, wingless live bee on the hard board in front of the entrance. I then looked in the brood nest, but saw no more wingless bees on the brood frames. But the brood frames had a so called shot gun pattern with a lot of “holes” where you would have expected capped brood as the other cells on the comb contained capped brood. Many pupae seemed to have been removed by the bees. Most likely not due to inbreeding as the queen had mated in the apiary and the number Elgon colonies in the neighborhood was quite high. No trace of any brood disease could be seen so I concluded that a likely cause could be cleaning out of varroa-infested brood. Or could the bees detect virus in the pupae and remove it, without there being a mite in the cell, and remove the pupae?
Could that be the reason why the colony developed so slowly – that the bees were throwing out mites? How had they managed? The wingless bee could indicate that they had not done so well and that the amount of mites was big. Now it was time for a Bee Shaker test to find out the level of Varroa infestation. (Here you can read more about The Bee Shaker, its uses and possibilities: http://www.elgon.es/diary/?p=809)
Here you can see a video clip when doing this test (sorry I’m talking my mother tounge Swedish):
The sample showed zero (0) mites! Then it’s no use to treat, There were far too few mites in the colony. Why had there been a wingless bee recently before the test?
July 8 I was visiting the apiary again. Once again I saw a wingless bee on the hardboard. But now I knew the Varroa level was low. Still no use treating. I looked in the brood nest. The colony was a little stronger still and the brood frames had fewer “holes”. The bees look healthy. They were recovering.
Virus apparently remain in the colony for a while after mites are eradicated – by the beekeeper or the bees.
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.
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.
Karin is a new beekeeper. She got thrilled when I took the feral swarm from the wall in one of her houses, so she wanted to keep bees. And got a daughter queen from the feral swarm. She is very happy with that. GM in Germany got one daughter too to this swarm. It’s the one with him that has no mites in the natural downfall.
I make queens for my own beekeeping operation in first place. I make some more to share with other beekeepers, selling them in Sweden and other European countries. I appreciate feedback from those I sell to. I hope it can help me in my work developing the Elgon bee.
One of the beekeepers I get feedback from is GM in Germany (of some different reasons he just now doesn’t want to use his name). He got some queens in 2014 and some in 2015.
He doesn’t like to treat bees with chemicals and looked for alternative ways of treatment free beekeeping. He wanted to start with queens that probably had better resistance traits than average against the Varroa mite.
He has one apiary at his home. Also he has a couple of new places relatively isolated from other bees. There are some colonies of Carnica bees not far from his home apiary. And quite some Buckfast colonies about 1 km away. So his home yard is not isolated.
One of the Elgon queens he got in 2014 was very promising with lowest natural mite downfall per day and good vitality compared to all his other hives. He succeeded in getting a few daughters from this queen. The original good queen was lost in a pesticide incident in May 2015.
In 2015 GM got some more Elgon queens. He also catched some carnica swarms. He wintered 15 colonies in 2015. In his home apiary he placed many new smaller colonies. He placed his new Elgon queens and daughters of the best one from 2014 in splits in his home apiary. All colonies in his home apiary are established on small cells, 4.9 mm. None of the colonies here was treated with chemicals, organic or not, against the Varroa in 2014 or in 2015. In autumn in 2014 he made a capped brood removal (both worker and drone), but not in 2015.
GM says it’s essential in treatment free beekeeping to have an understanding of the resistance status of the colonies to be able to act at the right time in a right way. Therefore during the second half of the season of 2015 he counted the daily natural downfall of mites in his home apiary. Each month he counted the downfall several times. Of the resulting daily downfalls, he calculated an average for each month.
GM finds mite count of natural downfall to be a tool for judging the resistance quality. Other tools he finds valuable are looking at hygienic behavior concerning mites in worker and drone brood, eventual presence of wingless bees (DWV), ability to produce drone brood late in season and ability to draw small cell foundation (4.9mm) correct.
This is sometimes called bald brood, a type of hygienic behaviour. The bees are identifying capped brood with mites and uncap such cells, sometimes recap them and uncap again, sometimes keep them this way, sometimes clean out the infested cells. As can be seen there are pupae in the uncapped cells, one almost mature. Bald brood can be seen together with colonies showing high VSH%, also with colonies with lower VSH. VSH can maybe be seen as a special case of this kind of hygienic behavior, uncapping and cleaning capped brood cells in which a mite has offspring. This is a daughter colony of a colony with high VSH.
GM focus on identifying the best colonies concerning resistance traits (for breeders next year), the loosers which will be requeened as soon as possible and the medium performers that maybe have a chance to learn how to fight the mite properly. Keep a special eye on those one he says, if they adapt well.
|Average||E1 (S241)||E2 (S241)||E3 (C243)||E4 (F1 of 242)||E5 (F1 of 242)||C1||X1|
The table is showing the average monthly natural downfall of mites, August-2015 – January-2016. E3 has a sister queen to the one in Karin’s hive.
About 25% of the mites from C1 (only from C1) at the end of December and January were lighter colored young mites pointing to brood in the colony. The table shows the monthly average daily downfall of mites from the colonies in the home apiary. (E2 was moved to another apiary and combined in late October.) GM used the overwintered Carnica colony, C1, to make many splits during 2015. This colony showed some DWV-bees (crippled wing bees) in early spring. They disappeared later, probably with the help of making many nucs and the appearance of drone brood. This colony also showed some hygienic behavior, uncapping brood with mites.
X1 is a swarm (looked like a mix of Carnica and Buckfast) he catched 2015 and hived on drawn small cell 4.9 comb. E4 and E5 have daughter queens of his Elgon queen from 2014. E1 and E2 had sister queens from 2015. E3 is a daughter (2015) from a feral colony in Sweden highly influenced of Elgon heritage.
You can speculate if the figures of E2 are a result of mites coming with the split from the C1-colony, from mites from the neighbor’s bees or less good genetics, or a combination. In any case the colony shifted its queen in late in autumn, and succeeded in getting mated in early October (maybe with Buckfast drones, as Buckfast colonies more often have drones later than Carnica)! The colony E2 was now small and was united with a small colony in another apiary. E2 had initially a few DWV-bees.
E1, E3 and E5 especially, seem to be interesting to watch the development of in 2016, test for VSH and maybe breed from.
If you want to know the Varroa level in the bee colony this tool is handy. Twice a season can bee good if you use it for example in selecting your breeders. And which colonies need a new queen (high Varroa level). It’s quick and you get an answer directly in the apiary.
Now a bee supplier in Sweden has the Bee shaker for sale. He calls it Erik’s Varroa shaker. Maybe it’s too expensive to send it to US. But some beekeepers in European countries no too far from Sweden may be interested. If you don’t want to make one yourself. http://www.elgon.es/diary/?p=660
You can communicate with the producer Bjorn Gagner through e-mail: firstname.lastname@example.org Price is probably somewhere between SEK 100-200 + shipping (about EUR 15 + shipping).
You can read more about it here: http://www.elgon.es/diary/?cat=85
The shaker is meant for making a an alcohol wash test.
- Fill one of the 500 ml jars to 2/3 with for example methylated spirit or rubbing (isopropyl) alcohol.
- Take a frame closest to a brood frame, don’t include the queen! She’s most probably walking on a brood frame.
- Shake the bees from the frame into a bowl or pan.
- Scope with a measuring cup little more than a deciliter (3.5 oz) of bees and pour them into the jar with alcohol (the bees die☹)
- Screw the glued lids with the netting and the the two jars together and shake for a minute.
- Turn the jars upside down and continue shaking until all alcohol has come down into the former empty jar.
- Lift the cans above your head to the sky and count the number of mites on the bottom of the lower jar (which now has the booze).
- If it is less than 3 mites in May and 6 in August you will probably do nothing about the mites.
- If one decides to treat, you can use several methods. One method is to use thymol. Another to remove all capped brood frames (worker- and drone brood) twice with a week apart. The latter method is perhaps the one to prefer if you breed varroa resistant bees. Because then you interfere the least with the epigenetic adaptation of the bees to fight the mites.
I understand that sometimes it’s a good idea to get an idea of the infestation level of varroa mites in bee colonies. You can take samples from a couple of colonies in an apiary to get an idea when to treat. But my first concern is breeding varroa resistant bees.
I have never monitored the varroa infestation level in my colonies. I haven’t had time and I haven’t found any reason for it because I thought I had found a good compromise – treating with Thymol when I saw wingless bees on the hardboard in front of the hive entrance, checking every 10 days or so.
Good results up till now
I give a colony one or two pieces of dish wash cloth containing 5 grams of Thymol each when I see wingless bees crawling on the hard board in front of the hive. But this means I don’t treat every colony at the same time (hopefully some not at all in a season). This results in some colonies with higher mite loads not showing wingless bees yet. So these colony (-ies) will through reinvasion increase mite levels again quite quickly in those colonies recently treated.
But this way I’ve been able to develop more and more resistant bees and still produce a good crop. There have been a number of bees not producing any honey. Winter losses have been reduced from 30 % to 10-15 % (except the first year with varroa trouble when I lost 50 %).
The bees have been better chasing mites and remove infested brood. I’ve got good reports from for example Poland and Germany of low populations of varroa in colonies headed by Elgon queens, compared to other bees. And the VSH trait is becoming better and better. Daughters of my colony with the highest VSH % (80) gave colonies that in Poland dropped 2-5 mites after effective treatment while other colonies dropped more than 1000.
Thymol is useful but hinders total adaptation
I now have been aware that by having this regime I have a constant quite high varroa population in the apiaries as a whole, and thus probably a climbing virus pressure. In a way this is good as selection is done also on virus resistance.
How do I know that? Now when I’ve used the bee shaker somewhat this year I’ve seen that colonies may show wingless bees (DWV-virus) at low mite infestation. Such low infestation you didn’t expect them to do so, sometimes even as low as 2 % infestation (a daughter from a colony with high VSH trait [80%]! This experience and others similar, raise the question if very high VSH comes with higher susceptibility to viruses.). Wingless bees at 2 % infestation is totally different from a report I’ve got from a test further down in Europe. (There they normally treat effectively every year.) In that test where they didn’t treat at all, my bees didn’t show any wingless bees at 35% infestation while other bees had a lot.
How to explain the high infestation level in the test
Now I have to try to explain why my good bees could arrive at 35 % mite infestation. This is interesting and brings up another topic as well. The importance of memories of the worker bees (their knowledge how to chase mites), not only their genetics (and epigenetic history). My queens in this test down in Europe were introduced to bees that had not been selected the same way as mine, and those bees had been treated effectively every year. The bees could probably not chase mites as well as mine.
But of course the genetics from my queens would more and more influence the workers to build up a better behavior when it comes to chasing mites. When the bees have arrived at a good mite chasing mood they learn new bees born in the colony what they have achieved, more than what just come directly with the genetics. In Norway with Terje Reinertsen and Hans-Otto Johnsen experiences are achieved pointing strongly to this.
In an apiary where many colonies are non-resistant as in this European test, you get a mixture of all bees in the apiary through drifting and robbing. This is taking place more and more when the mite populations in the colonies rise. As it did in this test as the colonies were not treated at all.
In a situation when colonies are receiving a lot of mites from neighboring colonies, even the very best kind of mite chasing behavior is maybe not enough to keep mite levels low.
In the test apiary previous to this test, effective treating every year had kept the mite and virus levels low, so the mite population could grow much in the test without showing wingless bees – like in the beginning when the mite first arrives to an area. Then the virus levels are usually very low and there could be 10 000 mites and more in a colony without any signs of viruses (documented case in Sweden in 1987 when the mites were first detected on the island Gotland in the Baltic).
The bees in this test were on 5.5 mm cell size, while my bees are kept on 4.9 mm.
Also Thymol hinders total adaptation
I have talked to some beekeepers whose bees are totally treatment free since many years (Hans-Otto Johnsen in Norway, Richard Reid in Virginia and Myron Kropf in Arkansas). Their bees have now small populations of mites and are showing no wingless bees.
I have come to realize that also Thymol is a chemical that hinders the bees to fully adapt to handling the mites successfully on their own. It is in first place the epigenetic adaptation I have come to think of that is disturbed when alien chemicals (like miticides of all kinds) are present. Epigenetic changes take place when a chemical change occur due to environmental changes, like for example the presence of the mite. (But it should be said also that if you use Thymol regularly spring and late summer in a system not selecting better bees like I do, winter losses can be kept low. I know because beekeeper friends do like this.) Also Thymol like other miticides is lowering the immune system of the bees.
How do I then integrate these insights to go further in becoming totally treatment free?
A new strategy to try
I’m planning a new strategy, at least to start with in one quite isolated apiary. I have to stop using Thymol. First though I think I have to knock down the mites effectively to reduce the virus level. And then get a better control of the number of mites and take action without any chemicals if varroa populations are rising too much in colonies.
The role of the bee shaker
Here the bee shaker will play a role. And I have looked more into how Randy Oliver uses it. It’s much easier to shake a frame of bees into a bowl or pan and then with a measuring cup scope somewhat more than a deciliter (3.5 oz) of bees and pour them into one half of the bee shaker, half filled with alcohol (for example methylated spirit or rubbing[isopropyl] alcohol). Then screw it together and shake for a minute before reading the result. Compared to holding the bee shaker close to a frame side with bees and pour bees into it moving it slowly upwards, the alternative of Randy Oliver is quicker (at least for me). The next step is to test the VSH trait in the best colonies.
Start checking from one side in the uppermost box with brood. The queen hopefully will run to the brood if she is outside the brood area (probably not). The comb closest to brood you check so the queen is not there.
Turn the shaker upside down and continue shaking until all the alcohol has poured down. Lift it up against the sky and count the mites. This colony had 14 mites on 300 mites and it got two pieces with 5 gram Thymol each. It showed no wingless bees.
What I hated to do
So what I’ve done so far is something I hated to do. In one quite isolated apiary I used an effective chemical miticide (only this time I promised myself) in August 2015. I wanted to use something else than Thymol to give the bees a break from that chemical. And I wanted to knock down the mite population effectively to lower the virus pressure in the apiary. I collected the knocked down mites. (In the rest of the apiaries I plan at the moment to continue as before.) The colonies that had needed most Thymol earlier in the season had the highest downfall of mites. They got probably continuously reinfested from other colonies that happened to not show wingless bees while they anyway had quite high mite loads. The defense system of these quickly reinfested colonies was probably lowered by Thymol, which made this relatively quick reinfestation possible.
One colony that hadn’t needed any Thymol at all (and very little the year before) and still had given me 80 kg (175 lb) of honey with 20 kg (45 lb) left for winter dropped less than 200 mites. And this happened in this very bad season of 2015. This colony is of course a breeder for the coming season.
The new strategy
Next year I will in this new strategy apiary make splits from the best colonies and place them in the same apiary (or if the number is enough there, place in other apiaries). In the least good colonies in this apiary (those with highest infestation level) I will kill the queen and give them a ripe queen cell bred from a good colony in this apiary. I check the number of varroa (infestation level) with the bee shaker twice a season in all colonies in this apiary. Each time it will take about 5 minutes per colony. And I look for eventual wingless bees on the hard board in front of the entrances. Before the number of mites rise too high (whatever that is), or when I see wingless bees, I plan to remove all capped brood (worker and drone brood) once or twice with a week in between. I haven’t decided what to do with those brood frames yet. Any suggestion?
‘The Beeshakers’ would be a good name for a pop/rock/soul-band/group, wouldn’t it? Why not a group of beekeepers that have control of their bees and the Varroa infestation?
Regardless of if you are on the path of becoming treatment free or treating with whatever to get rid of pathogens and parasites in your hives (and creating other problems probably along the way – that goes for both groups unfortunately). Agree we can that the world would be a better place for bees and men without killers. That’s why treatment free is the goal!
A year ago I wrote about the bee shaker: http://www.elgon.es/diary/?p=354 Here are some more tips how to get control of the Varroa situation in the hive.
When a colony has problems you can speculate and discuss about how many mites there are in the colony. If that’s why the colony is dwindling. With a high number of mites often follows virus problems, more sensitivity to plant protection chemicals and more susceptibility to Nosemas, and all of this together in a spinning wheel. You can know the mite infestation much better with this simple method that is quick and done on the spot in the apiary, with some training in a few minutes per hive.
Make the beeshaker
I used two plastic bottles containing peanut butter of the brand Skippy, a bee tight but not varroa tight netting, mesh size 3 mm, a plate shears, a proper sized hole saw (in this case for a 60 mm hole) and a soldering iron at 80-100 watts.
Get rid of the peanut butter and wash the bottles. Saw holes in the lids. Cut a piece of mesh so it fits inside the lids and covering the hole. Put one of the lids on a table, then the piece of mesh, finally the other lid upside down. Keep it all together with one hand (or some one else’s hands). Solder the caps with the piece of netting in between.
Pour one deciliter (3.5 fl oz UK; 3.4 fl oz US) in one of the bottles. Mark the waterline around the bottle with a black marker pen. Get rid of the water. Now you have calibrated the bee shaker. When you fill this jar with live bees up to the black line you have close to or exactly or somewhat above 300 bees, enough accurate so you don’t need to count them. (If you use 2/3 of a deciliter you get 200 bees.)
Make a test
Don’t take bees close to the entrance. They have bad correlation to the real amount of mites in the colony, fewer mites on those bees. Take bees relatively close to the brood, but not from a comb with the queen (poor queen if she should end up in the shaker). You may well take bees from a comb without brood, but close to the brood. In the upper brood box is a good choice if you use two brood boxes. Check for the queen! Avoid the outermost comb in the box, unless brood is close and it’s filled with bees. Most secure and quickest is if you use queen excluder and you have super(s) above it (depends on the season of course). Take bees from the center of the first super close to the excluder.
Take the jar with the black line (black color doesn’t fade so easily by the sun), hold the opening close to bees on the comb and move it from below upwards. Bees will tumble down. Hit the bottom of the jar gently against something sometimes so that the bees will be shaken down on the bottom. You then see easier when you have enough of them.
Before this procedure you have poured 2 deciliter of some kind of high content alcohol fluid into the other jar. The soldered caps are on top of it (there’s a hole you know you can pour through). Pour the alcohol into the jar with the bees. They die. Screw the lids with the other jar onto the jar with the bees and the alcohol. Shake it for a minute, not too hard and not too soft, “lagom” as we say in Sweden (a frequently used word when you don’t know what word to use). Turn the shaker upside down. The alcohol and the mites will go down. The bees stay above. Lift the shaker up towards heaven. The light will shine through and you can count the mites. (Live mites now killed will sink to the bottom. Dry mites from natural downfall will float. Just want to make clear the difference.) Recycle the alcohol through a fine mesh into the now empty jar to get it ready for the next hive.
Count and calculate
You may find 9 mites on your 300 bees (which you DON’T have to count, it’s enough with the calibration done to get an enough good estimation of the mite infestation). That’s 9/300 = 3/100 = 3% infestation. You can find that small or big, depending on when you did the measurement and what you are up to. Maybe you are in the middle of a breeding program for Varroa resistance. Maybe you want to find out when to treat, so you will not treat to late, or making an unnecessary treatment.
In spring, especially in a breeding program for resistance, you don’t want 3% infestation. If you’re in a breeding program you will probably take another measurement a month later. If you’re not, you maybe want to treat now, if you find something that’s good using in spring (there’s really only one option here that is least damaging in different respect, thymol).
If you get 3% after the main crop in the middle of July or in the beginning of August (or September maybe), you may decide not to treat if you’re in a breeding program. If you’re not and the bees will be without brood in November or December (on higher latitudes in Europe and Canada) and you plan to use Oxalic acid (which I don’t recommend for different reasons [though you’re the boss in your operation]) you may wait until then. If you consider pesticide strips or Apiguard (Thymol) or Formic acid, you may decide for that now.
If you get 3% in October, November just prior using Oxalic, you may decide not to use any Oxalic. Like a friend in our resistance breeding program here in Sweden. He has the limit 5% for deciding when to treat. All colonies below that limit don’t get any treatment with him.
If you treat all your colonies whatever figures you get in your measurements because you hate the mites that much, you get at least figures you can use in selecting the ones with the highest numbers. Those are the ones that should have their queens shifted in some way.
More to read
http://svenskbihalsa.se together with Google translate
Another Swedish alternative of the BeeShaker, Varroa Sampling Tool, which is for sale from http://svenskbihalsa.se
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.