Varroa resistant worker bees

Magnus was a beekeeper in his youth in western Sweden. He quit in 1996 but started again in 2013 with his wife Ulrika. Then they bought from an older beekeepers a pavilion with seven bee colonies, most of which were splits, new colonies.

Varberg1 It was a big pavilion on wheels that they bought.

It was not crowded with bees where this beekeeper lived from whom they bought the bees. Maybe a couple of miles (3 km) to other bees than his. He treated with oxalic acid against Varroa once a year. Nothing more was used for keeping the Varroa population down. And he bought a Buckfast queen now and then to help the genetic variation.

Varberg2 The hives in the pavilion are long hives with 30 combs 12″x12″ (30 x 30 cm).

The pavilion was moved to Magnus and Ulrika in September. They saw wingless bees from three colonies. Two of these were splits from the third. Of the other four were at least two splits from one of the rest, No. 9. The fourth, No. 10, appeared to be related to No. 9, because of the behavior and appearance. Maybe No. 9 was a split from No. 10 in 2012. The argument for this is that in 2014 the queen just fell of the combs in No 10 and died. Perhaps the queen was the oldest of the two.

Magnus and Ulrika has their bees quite isolated too (about 3 km) in relation to other bees. In October 2013 they treated all seven colonies with oxalic acid. From the three with wingless bees fell very many mites due to the treatment. From the other four just about 10 mites from each. These four were also the only one to survive the winter.

 

Low level start in 2014

In August 2014 they treated all colonies with thymol. Now they were ten. Magnus and Ulrika wanted to bring all colonies into a low level situation concerning mites as a start for the coming years. The next year they planned to check the infestation level of mites with the bee shaker bootle and treat only those with an infestation level of at least 3% in August.

They probably did too many splits, as some were a bit weak in autumn. No. 10 was still there, but with a new Buckfast queen from a queen breeder. No split had a daughter of No. 9 or No. 10 as its queen. Only No. 9 had its original queen.

No colony had been purchased and brought into their area from “outside”. All new colonies were splits from the first four who survived the first winter with Magnus and Ulrika.

The mites that fell after thymol treatment were about as many as the previous year after the oxalic acid treatment, that is very few.

Seven survived the winter. Three splits were obviously too small and did not make it.

 

Bee shaker 2015

In autumn 2015, they wintered 13 colonies. They controlled the infestation rate in August with the help of the bee shaker (http://www.elgon.es/diary/?p=794), ie alcohol sample of 300 bees. Only the “old” colonies were tested. Magnus and Ulrika did not want to weaken the splits made in 2015. Two of these were a bit weak in the autumn due to queen problems. If an “old” colony had more than 3% infestation rate (9 mites from 300 bees) also the splits made from it would be treated was the strategy.

Those which had higher infestation rate than 3% in August were treated with thymol. There were three colonies that had just over 3%. Only those three which no splits had been taken from. Some of the other “old” colonies had only one mite from 300 bees, i.e. 0.3% infestation level. All the others except the three were not treated.

Ten colonies survived to 2016. Two of the three dead were the weak due queen problems in the autumn. The third died of local starvation. There were some empty frames between food combs and the bee cluster.

No colony during the last two winters have died because of large levels of Varroa. Varroa is evidently not a problem. Varroa levels have always been low in these colonies that originated from bees from the No. 9 and No. 10, also in 2013.

 

The colonies from the No. 9 and No. 10th

What naturally would come to mind is that we have found a tiny varroa resistant local bee stock genetically, if the queens are all descended from the No. 9 and No. 10. But that is not the case! Several of the daughter colonies had received queen pupae from a queen breeder. Some had been laying queens from the same breeder. He doesn’t select for varroa resistance and use effective miticides. Still, even colonies with these queens have very small levels of varroa. But the worker bees that these queens were introduced into came directly or “indirectly” from No. 9 or No. 10. Some splits from No. 9 were made in 2015. The other “mother colonies” were splits made in 2014 from No. 9, though with queens from a Buckfast queen breeder. These colonies are not ffsprings genetically, “only” “social offsprings” through the worker bees. The colony No. 10, is the social offspring of the original No. 10. Eight colonies are social offsprings of No. 9. No. 9 have the original queen. Only No. 9 have a “true” varroa resistant genetic set up.

 

Naturrum 2016

The first weekend in April 2016, I had a lecture at the Visitor Centre at Getteron at the west coast of Sweden close to the little town Varberg. I talked about breeding bees resistant to varroa. In the afternoon there were some workshops. One on how to check the infestation level of Varroa with the Bee shaker. The other how to make dish cloth pieces with thymol to treat against Varroa.

Varberg3 Magnus and Ulrika pouring alcohol in the Bee shaker. Somewhat more.

Magnus had brought a colony that hadn’t been treated against varroa the previous year. The queen was an introduced egg-laying Buckfast queen from a queen breeder. A queen which was not selected for varroa resistance. We hoped it would be a substantial amount of varroa in the colony so there would be some to count at the bottom of the Bee shaker.

Varberg4 The fourth comb from the rear with a lot of bees on it but no brood, to minimize the risk of including the queen.

Varberg5 The bees were shaken into a corner. With a measuring cup a little more than 1 dl bees were talken and poured into one half of the Bee shaker.

Varberg6 After the bees had been poured into one half of the Bee shaker the lids were screwed on top. Then the alcohol was poured on the bees from the other half. This half was then screwed to the rest. Now the Bee shaker was shaken for one minute. Turned around, still shaken until all the alcohol had went down in the lower part.

 

Too few mites

In August 2015 it was one mite in 300 bees in that test colony at the workshop. Now April 2 the colony was a strong and healthy colony of bees filling the box that had been the winter room. The bees were very calm and sampling went well. I lifted the fourth comb from the rear, with no brood, but close to the brood. To our “disappointment” it showed only one mite in 300 bees. One can truly say that we were surprised.

Varberg7 When all the alcohol had went down, the Bee shaker was lifted above the head and the mites were counted on the bottom of the Bee shaker.

How could this colony be varroa resistant? And No. 9? And the colonies that were made with bees from No. 9 but with no daughter queen from No. 9. All Magnus’ and Ulrika’s current colonies and their social offsprings have demonstrated surprisingly low amounts of mites all of the years with them. Although their queens are not genetically related to the original resistant colonies. They are though social offspring, as described above what that means.

 

The explanation

I had in my lecture talked about the experience of Hans-Otto Johnsen and Terje Reinertsen in Norway that can hardly be explained otherwise than that worker bees in resistant colonies teach other bees how to control mites.

Sampling with the Bee shaker on Getteron confirmed what I had lectured in a most interesting way.

 

Look for resistant bees

Now is the time for beekeepers that have had varroa in their colonies for a few years and have not yet checked the downfall of mites after treating. Check the differences of downfalls between different colonies. Especially you can discover good colonies in apiaries located somewhat isolated and in which there are not so many bee colonies. This lessen the risk for reinvasion of mites in the colonies. It’s good if the apiary have somewhat developed a stock of its own, ie no colonies or packages have been brought into the apiary in recent years and mostly queens have been bred from colonies in the apiary.

I’m sure there are many resistant colonies to be found today, but you must look for them.

You should make splits from the best ones.

The poorest colonies should not be used to make splits from, in any case you should avoid it.

You can buy Bee shakers here: http://www.elgon.es/diary/?p=809

 

Resistant genes are important but resistant worker bees are more important

Of course, it requires a certain amount of resistant genes for a colony of bees to be able to develop resistance and be able to teach other worker bees how to control mites. When there are colonies which have developed good resistance it seems less genetic resistance quality is required to be able to be taught ability to control mites than to initially develop and learn this property.

 

If you find resistant colonies

If you find resistant colonies, even if they are somewhat bad tempered, swarmy, and only give small crops of honey, take care of them like golden nuggets. Move them if you can to an apiary of their own somewhat isolated, a couple of miles (3 km) to the other bees. Make splits from them and give those splits pupae bred from good tempered bees, reluctant to swarm and high producing.. Then continue to do splits following year from the best varroa resistant colonies and let them make their own queens. Doing so also from the original resistant colonies and let them make their own queens. Now there are good drones in respect to other good qualities from the previous year’s new colonies. Continue the following years to replace the poorest queens with those bred from the best in the apiary.

Feedback on Elgon queens

GM 243-daughter 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.

GM Bald brood  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 Utrensad puppa Observing cleaned out pupae is most probably a sign of the colony showing some kind of hygienic behavior towards Varroa mites in the colony.

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
Aug-15 1 6 0 2 3 10 1
Sep-15 1 24 0 4 2 11 2
Oct-15 1 3 requeened 0 15 1 16 4
Nov-15 1 13 0 8 1-2 14 2
Dec-15 1 1 0 2 1 5 1
Jan-16 0 0 0 1 0 6 0

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.

Bee shaker for sale

Varroa Shaker_20160117_003

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: bjorngagner@gmail.com 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.

  1. Fill one of the 500 ml jars to 2/3 with for example methylated spirit or rubbing (isopropyl) alcohol.
  2. Take a frame closest to a brood frame, don’t include the queen! She’s most probably walking on a brood frame.
  3. Shake the bees from the frame into a bowl or pan.
  4. 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☹)
  5. Screw the glued lids with the netting and the the two jars together and shake for a minute.
  6. Turn the jars upside down and continue shaking until all alcohol has come down into the former empty jar.
  7. 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).
  8. If it is less than 3 mites in May and 6 in August you will probably do nothing about the mites.
  9. 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.

 

 

The bee shaker and varroa resistance

Skak botten 2lc One mite from 300 bees.

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.

Skak yngelrum 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. 

Skak deciliter Shake the bees into a pan or bowl. Scope up somewhat more than a deciliter of bees (3.5 oz)

Skakburk sprit Pour the bees into one of the halfs of the bee shaker, which is half filled with alcohol. Screw the other half tight on top. Shake it for a minute.

Skak botten1lc 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

‘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.

Biskak1

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.

Biskak2Biskak3Biskak4

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.)

Biskak5

 

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.

Biskak6

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.

Biskak7 Randy Oliver counting

Biskak8

 

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://scientificbeekeeping.com/sick-bees-part-11-mite-monitoring-methods/ eller kort url: http://alturl.com/np8ez

http://svenskbihalsa.se together with Google translate

Biskak9Biskak10 Another Swedish alternative of the BeeShaker, Varroa Sampling Tool, which is for sale from http://svenskbihalsa.se

Sugar Shaker

Ssugarshake1

Larry Garret uses the powdered sugar shaker method to count mites. The method works well for his smaller number of colonies at each apiary and the tools are very easy to transport and store. Although there may be a slight difference in the actual counts provided via sugar shaker from those provided via alcohol wash the key is that the method and counts are consistently reproduced for comparison, he says. Above is a picture with his tools, below a result.

Ssugarshake2 Ssugarshake3

After each “shake” he writes the results on the back of the hive. The photo below shows a “hive log” of 2.3% mite infestation on 4 October with an oxalic acid dribble on 1 November.

SshakeLog

Randy Oliver tells us: The alcohol wash methods have the drawback of killing the bees, and possibly the queen if you’re not sharp eyed. Paula Macedo and Marion Ellis came up with a bee-friendly jar test (Macedo & Ellis 2001). Set up a jar as for alcohol wash, with a 1/8” screened lid. Shake in 300 bees from the broodnest, put on the lid, and sift 1 rounded tsp of powdered sugar through the lid onto the bees. Roll the jar until the bees are all white, then let them sit for a minute. After one minute, invert the jar over a white surface (or better yet, a white pan of water so wind doesn’t blow the mites away), and shake the sugar and mites out for a full minute (continue if mites keep falling). Macedo recovered about 80-90% of the mites; in my own tests, we recovered about 65-70%. The bees can be returned to the hive unhappy but unharmed. http://scientificbeekeeping.com/fighting-varroa-reconnaissance-mite-sampling/

Bee shaker

I wrote about counting mites recently. Even if I don’t, others do, and sometimes it gives information that may help you make a decision.

John Harbo mentioned when he lectured in Sweden in May 2013 that before choosing the method for selecting for varroa resistance at the lab in Baton Rouge in the 1990th, their statistician helped them evaluate different methods. Their conclusion was that selecting for infertility of mites, then called SMR, later VSH, was the best method. Using one-drone insemination on 43 queens from a source of collected survivors they started the work in 1995 and in 1998 the goal was achieved. Impressing to say the least. Why havn’t this result have had more impact during the years. The queens produced at that early stage in the process were so inbred they were superceded quickly and the honeyproduction was low. They got bad reputation and beekeepers didn’t understand how to use the resistant queens fully. The situation today is very different.

One selection method among those not choosen, was checking the mite population. Though this method is still promoted buy others and used as well. Maybe because some have found it valuable in this matter. And most of us are living in free countries and can do our own choice.

Another reason for doing mite counts is for making a desicion if or when mite tretament is needed. In US it’s been said the threshold for treating is 3 mites per 100 bees in an alcohol wash. Some say this number seems to have to be lowered as viruses are worse nowadays. That probably is valid for all those moving their bees to almond pollination, where the bees share the latest in pathogens, pests and pesticides. Maybe all this treatment used during the years has forced the mites to answer with reproducing quicker in that they stay in the phoretic stage (on the bees and not in the brood) for a shorter period before they enter brood cells again.

Anyway, my small scale beekeeper friend cooperating with me, Leif Stromberg, quite on his own with his bees but not totally; he has 15 colonies, use the threshold 5 mites per 100 bees for treating, in october only when there’s no brood. It’s a help for deciding if he shall trickle oxalic acid. He trickled 4 colonies in autumn 2013. His winter losses are small. He lives 100 km north of me and cooperates there with Bjorn Lagerman, 90 colonies, with basically the same stock of bees as me too. His story could be told in another post.

HDRtist Pro Rendering - http://www.ohanaware.com/hdrtistpro/ Pouring bees in the bee shaker (pictures used with the kind permission of Randy Oliver).

Leif has compared natural dropping of dead mites through the season and this late alcohol wash. And there is actually very little correlation, if any. His conclusion is that natural downfall of mites is of no practical value to get a good idea of a mite population having an impact on the bee colony, at least when it comes to his bees (he gets a couple of virgin queens from me every second year or so) that apparently has some resistance to varroa. Randy Oliver has also lost faith in the natural mite drop method for determining the actual mite population. http://scientificbeekeeping.com/mite-management-update-2013/

Shaker2 After shaking for 1-2 minutes, turn the shaker around…

Randy Oliver uses a very practical way of alcohol wash, the bee shaker. For some time John Williamson produced it for sale, but doesn’t anymore. As far as I know, no one does at the moment. But it takes 5 minutes to make one yourself from two suitable cans with plastic lids and a piece of beetight netting that let through mites. Follow the instruction here: http://scientificbeekeeping.com/sick-bees-part-11-mite-monitoring-methods/

Shaker3 … and count the mites