Saving a hive from advanced PMS with powdered sugar only!!!

[fafrd]

Since the title of my original thread started in October was not appropriate for the below summary/recap, I am reposting my results here with a more appropriate title:

-fafrd

After losing my first hive to PMS this summer, I had a second hive showing signs of advanced PMS in the fall. Very high 24 natural drop mite counts (100's), bees with DWV outside the entrance, spotty brood pattern. This hive had been a strong double deep hive coming out of the summer, but by late October had started to dwindle and was down to about 1 deep (2 half-deeps).

I had never tried powdered sugar dusting before but decided to see if I could save the hive by dusting extensively (daily / whenever possible) over a several week period.

Between October 26th (when I started) December 3rd (the last time I have dusted), I dusted this hive a total of 25 times.

My other posts report the detailed mite drop data, so I will just recap a summary here:

Date(s) . . starting 1-hr dusting drop . ending-1-hr drop . average over period
10/26-11/1 . . >250 mites . . . . . . . . . . . 15 mites . . . . . 685/7=98 mites
11/6-11/14 . . . 110 mites . . . . . . . . . . . 30 mites . . . . . 207/7=30 mites
11/23-12/3 . . . . 25 mites . . . . . . . . . . . . 1 mite . . . . . 123/10=12 mites

The last three times I dusted the hive, there were only 2,3 and 1 mite, so this is when I stopped.

So one conclusion is that by dusting 24 times over a 38 day period, I virtually eliminated mites from the hive.

Another conclusion is that daily dusting did not appear to harm the bees in any way. The brood cluster was always cleaned of sugar by the next day (though as the hive dwindled from the effects of PMS, the empty frames towards the outside began to show signs of residual sugar from one day to the next).

On October 26th, when I started, the hive had 2 frames of open and capped brood in the upper deep, on top of 4 frames of open and capped brood in the lower deep. There were probably about 10 frames of bees total at that time and the brrod pattern did not look good (spotty).

By November 14th, the hive had dwindled down to 3 frames of brood and less than 5 frames of bees but the brood pattern had improved on one frame to a small, solid cluster.

On December 1st, the hive had dwindled to 2-3 frames of bees, no open brood, only a single frame 25% full of capped brood. I spotted the queen and she looked fine. At this point I was down to a small nuc and compacted the hive/nuc into a single deep with the cluster in the middle and stores on either side.

On December 24th, I did a quick inspection and the hive/nuc now has a softball-sized cluster spanning three frames with open and capped brood and a good pattern. Quick inspections of the bottom boards have not shown any signs of mites, but I will try to do a more careful 24-drop measurement or another dusting when we next get a clear day.

In a colder climate, this hive would be dead by now, but because I am in California where our winters are relatively mild, I think this hive/nuc has a good chance to make it now. The bees are already bringing in tons of pollen and the nuc is expanding, so unless we get a severe cold snap and the bees do not survive because of lack of critical mass to maintain the temperature of the brood cluster, I believe this hive which was severely stricken with PMS has been saved with nothing but powdered sugar.

If I were to try this experiment again, I think I would not have tried to save the brood at the beginning. If I had removed all open and capped brood (brushing the bees back into the cluster) and confined the queen to my Nicot cage for a few days, I believe I could have eliminated all of the mites in the first few days of dusting between 10/26 and 11/1. Then releasing the queen she could have immediately started to establish fresh uninfested brood while she had a larger mass of bees to establish a larger cluster and I would not have had to keep dusting to clean out the newly-emerging mites from the infested capped brood.

The theory about dusting is that it knocks off approximately 50% of the phoretic mites in a single 24-hour dusting. My results generally support this, and assuming that this is correct, sacrificing all open and capped brood, confining the queen, and dusting 5-7 times as quickly as possible should reduce the phoretic mite count to between 1/32nd and 1/128th of the starting level. Strictly speaking, the queen can be freed 4 days before the dusting is finished, since the mites should not be able to enter open brood that is less than 5 days old.

Another option if one has a spare queen or is treating two infested hives would be to split the hive and use one split/hive with a confined queen to emerge all infested open and capped brood over a full 21-day period, only dusting down the phoretic mites once the brood has all emerged, and use the other split/hive to begin establishing uninfested brood after first dusting out the phoretic mites over a 5-7 day period. 4 weeks after this treatment, one uninfested split will have uninfested open and capped brood, many foragers and few nurse bees, and the other uninfested split wll have no brood but many uninfested nurse bees - recombining the splits (or rebalancing the hives) should result in a stronger hive(s) than if an entire generation of open and capped brood is lost.

I hope I never allow one of my hives to become this infested with Varroa again, but I have learned a great deal from this experiment and it has made me a believer of the powdered sugar treatment approach if it can be applied properly. Dusting once a week for three weeks is pretty much of a complete waste of time but dusting daily for 5-7 days without brood should be an effective way to all but elimiate mites from a hive. This technique would probably not be practical for a commercial operation, but for any hobbiest searching for ways to help his bees fight off the mites without the use of chemicals, I believe that intensive broodless dusting is an option to strongly consider.

-fafrd

[fafrd]

As a quick update to the status of my recovered hive/nuc, I did a careful 24-hour natural mite drop count yesterday. There were a total of 5 mites, one of which appeared to be immature. On a cold day with all of the foragers in, it looks like there are a total of about 3-4 frames of bees so this double-deep strong hive suffering from advanced PMS has now been reduced to a medium-sized nuc, but the infestation from mites is down to a manageable low level and the bees appear much healthier. They have stores, they are bringing in tons of pollen on any day reaching the 50's (which is most days lately), and I am pretty confident the hive is on the rebound.

The bees should now be growing at a much faster rate then the mites and so in any case, I expect the mite problem to be in check until the late summer. I plan to continue to monitor mite levels on a monthly or bi-weekly basis and will continue to post updates on this 'naturally' (no chemical treatments use) recovered hive.

-fafrd

[beekuk]

Sounds like it lot of mites to be dropping naturally in 24 hours,think they will need treating soon,long before the end of next summer.

https://secure.fera.defra.gov.uk/bee...Calculator.cfm

[Oldtimer]

Yes, although I've been very interested to see your success, and you have done well, imho 5 mites daily natural drop from a 3-4 frame nuc, at this time of year, is highish.

The question is can the bees outbreed them? I'll be following the thread with interest to see how you go, and if you have to continue the sugar treatments.

[alpha6]

Brother....if you want an accurate mite count use an alcohol wash. If you are basing your mite counts on natural drop and dusting you are doing your bees a dis-service. If you don't have a problem dumping all that sugar on them why not feed some 1:1 with some thymol in it. That would elimate your mite problem. Good luck.

[fafrd]

Yes, although I've been very interested to see your success, and you have done well, imho 5 mites daily natural drop from a 3-4 frame nuc, at this time of year, is highish.

The question is can the bees outbreed them?

At this time of year, the bees should be able to outbreed the mites and I think that the absolute numbers of mites should be more important that than infestation %.

As long as the mite numbers are significantly less than the number of open larvae approaching the capping stage, the bee population should be growing at a rate that is at least twice as fast as the mites, meaning that infestation % should be decreasing until the hive reaches full strength in the late spring / early summer

Let' say I've got about 1/6th of a full strength hive, or about 10,000 bees at the moment. The amount of open and capped brood I saw would total to at least one side of one deep frame, so let's say 3000 cells. Assuming this brood has been laid down continually over a 21 day period, this would correspond to about 150 new cells being laid per day (which is worst-case, there is amost certainly more laying going on now, so the actual number of larvae per day is likely already significantly higher).

If we assume that the 24-hour natural mite drop reflects the number of new viable foundress mites emerging in 24 hours, I've got something like 5 foundress mites infesting 150 newly-capped brood cells per day, meaning that at most 3% of the fresh brood is being inifested (meaning more than 97% of the new brood is not being infested).

At this relatively low level of infestation (from the point of view of having the vast majority of the newly laid larvae emerge unscathed), the bees ought to be up to a population of 30,000 bees or more a month from now and the laying rate should be up to at least 500 new eggs per day. Limited to worker brood, the mites should have only succeeded to double their population over the same month (beginning of February), meaning that I can expect to have something like 10 foundress mites infesting 500 newly-capped cells, or down to 2% of the newly capped brood being infested and 98% of the newly emerging brood being unscathed.

Over the subsequent month (beginning of March), the bees will only double their population to a full-strength of 60,000 bees, meaning that the bees and the mites will be growing their populations at about the same rate and the contamination rate will remain at about 2%.

From that point forward, the mites will continue to double their population every month while the bee population will remain relatively constant (unless I simulate a swarm by making a split), meaning that the contamination rate will double every month to 4%, 8%, 16%, 32%, by which time (end of July) I will certainly be back in PMS land if I have not taken some action.

I'm going to continue to monitor the 24-hour natural drop counts to see how this hive handles the greatly reduced mite infestation they now have. By no means is this hive now mite-free, but I believe I have gotten the mite infestation down to a level that if the bees have any VSH genetics or other traits that allow them to combat the mites without my help, they shold have a chance. By monitoring the mite levels from here on out, I hope to learn something about how they are doing.

[fafrd]

If you don't have a problem dumping all that sugar on them why not feed some 1:1 with some thymol in it. That would elimate your mite problem. Good luck.

I'd prefer to avoid chemicals of any kind if I can. I am not concerend about the impact of sugar and a bit of starch on the hive and the honey I hope to extract from it. Dusting with PS seems to me to be far 'safer' than messing around with any kind of chemical whose dosage level, etc... needs to be carefully monitored and whose impact on the honey and the wax is more questionable.

I was worried about the impact of 'dumping all that sugar' on the bees, but now that I have actually tried it and seen firsthand how the bees deal with it, I am comfortabel that this 'mechanical' treatment has far less impact on a hive than virtually any other form of treatment. More work, probably. Worse for the bees, no.

-fafrd

[beekuk]

Keep us in touch with your findings,will be interesting to see how it goes.
If the calculator is anything to go by, they could have anything from 500 to 2000 mites at this present time.
I use very similar methods to Alpha regards control.

[fafrd]

Pete,

thanks for the link to the calculator. Not sure how it forms the basis of the calculation, but the mite levels it is estimating seem high to me (and I assume it is counting all mites including phoretic and foundress).

I did another 24-hour natural drop mite count and this time got 2 mites.

I don't have too much experience with natural drop mite counting - it seems pretty variable. I may do a count over a full 7 day period as the calculator suggests that averaging over 7 days is a good way to get a more meaningful count.

I have more experence using a 1-hour post-PS-dusting drop count, and the next sunny day we have, I will get a count using that technique as it is probably a better baseline for this hive that I was treating and monitoring earlier using PS dusting.

Based on what I have read, I've been assuming that the 24 hour natural mite drop is a approximate measure of the number of new mites emerging. If 5 cells emerge, there should be about 2x5=10 mites emerging from those cells out of which approximately 5 should drop or die over the subsequent phoretic period of 5 days. In a steady state, 10 mites emerge every day, 5 drop every day, and 5 new cells get infested by foundress mites just before capping. Total number of adult mites would be 5 days x 5 phoretic mites per day = 25 phoretic mites and 13 days x 5 foundress mites per day = 65 foundress mites for 90 mites total. Of course,steady-state is better than best case, and since the mtes are growing at about 2% per day, the actual number will be worse (but less than 2 times worse).

So I can see estimating mite numbers as high as 200 or so based on my natural mite drop count of 5 in 24h, but not 500. The calculator obviously must be based on a different set of assumptions, one of which may be that I now have no drone brood in my hive and the calculator does not seem to provide that as an option.

I will keep everyone posted on how this experiement evolves.

What level do you typically drop you mite levels to by winter using your tymol treatments?

-fafrd

[beekuk]

>What level do you typically drop you mite levels to by winter using your tymol treatments?<
fafrd
Usually down to no mite drop at all,using emulsified thymolised syrup feed,and thymol pads in autumn,also acts against nosema.

[fafrd]

Thanks. No mites dropping over what period? And is your thymolised syrup being fed during a period of broodlessness or could there be some surviving foundress mites hiding out within capped brood?

I'm hoping to avoid the use of chemical-based treatments including thymol, but since you seem pretty happy with your thymol treatments I would be interested to learn more:

Do you have any concerns about the effect of residual thymol on honey or comb?

How long to you apply the treatment?

Is the dosage level critical and if so how do you control it?

Are there any other negatives to treament with Thymolized syrup that I am not aware of?

I'm still a relative newbie (entering my second spring) and in the learning phase, so I would appreciate any additional information you can provide.

-fafrd

[beekuk]

fafrd
i will reply to your questions tomorrow,if Alpha does not beat me to it.

[alpha6]

I'd prefer to avoid chemicals of any kind if I can. I am not concerend about the impact of sugar and a bit of starch on the hive and the honey I hope to extract from it. Dusting with PS seems to me to be far 'safer' than messing around with any kind of chemical whose dosage level, etc... needs to be carefully monitored and whose impact on the honey and the wax is more questionable.

I was worried about the impact of 'dumping all that sugar' on the bees, but now that I have actually tried it and seen firsthand how the bees deal with it, I am comfortabel that this 'mechanical' treatment has far less impact on a hive than virtually any other form of treatment. More work, probably. Worse for the bees, no.

-fafrd

Thymol is an EO, not a chemical anymore then the processed sugar you are using. Bees naturally bring back these oils into the hive when forging on Thyme. So in that sense it is more natural than the highly processed powered sugar you are using on them. But...to each their own. Good luck with your powered sugar treatment when the mites really start to kick in at the end of summer. Controling mites at this time of year is not really an issue...not much brood for them to breed in.

[alpha6]

I'm hoping to avoid the use of chemical-based treatments including thymol, but since you seem pretty happy with your thymol treatments I would be interested to learn more:

-fafrd

Sorry, just read this post. I am happy with the way Thymol works and my bees are much more healthy for it.

Do you have any concerns about the effect of residual thymol on honey or comb? - No. I feed in the spring and in the fall when no supers are on. From everything I have read there are no negitives with thymol, including any kind of resistence built up by the mites as is the case with some chemicals used to treat mites. The dosage level is important as too much can cause your bees to act drunk and disoriented but then again all EO's are very powerful and should be used in the minimal amounts that are effective. HBH is comprised of both spearmint and lemongrass EO's...good for the bees but not if you use too much of it.

I run hundreds of hives and since starting treatments with Thymol three years ago I have had zero mite problems. I run alcohol washes on my bees to get an accurate mite count and have from zero to three counts at all times of the year which is to say that there is between zero to 1% infestation in my hives. I swear by the stuff and other commerical beeks around here are seeing the results and swiching from the likes of Maverk and Havistan to Thymol.

Hope that helps. I have posted good recipes on beesource if you do a search for them if you need the mixture amounts.

Again good luck...we all want to see heathy bees.

[fafrd]

Alpha,

thanks for the post and the information. I will check out your recipes. If I have to try a more 'serious' treatment than just PS, Tymol may be the first I consider. I was scared away from it partly because of concerns of some residue making its way into the honey, even if supering as you do.

I have witnessed my bees move their honey around, so there is no guarantee that 100% of the honey in a honey super has come from new post-treatment nectar.

Of course, the same comment can be made about any artificial nectar feed as well as powdered sugar, and if you are correct that bees foraging on Thyme naturally bring a certain amount of tymol into the honey anyway, this concern may be overblown.

I will look into it and let you know if I decide to give it a try.

Since you have obviously done quite a bit of research on the subject, what do the naysayers point to as the negatives and/or drawbcks of tymolized syrup treatment?

-fafrd

[Oldtimer]

Beekuk and Alpha I'd be pretty interested in the full rundown on how you treat with thymol.

I've started another thread for you, here it is:-

http://www.beesource.com/forums/show...811#post605811

[TxFirefighter]

http://www.henriettesherbal.com/ecle...gs/thymol.html

This will tell you everything you want to know about the makeup of Thymol.

[Oldtimer]

Thanks TxFirefighter, good info.

I'd still like to hear from those guys though, how they are actually using it.

[fafrd]

It was nice out today so I checked mite levels in my recovered hive. Here is an update:

Natural mite drop:

Dec 30 - 5 in 24h
Dec 31 - 2 in 24h
Jan 4 - 6 in 96h

6-day natural mite drop: 13 (a little over 2/day average).

I have been assuming that the natural mite drop is related to the rate of mite emergence, so at an average of 2/mites per day dropping, I would assume the number of phoretic mites to be between 5-7 days worth of emerging mites (5-7 days phoretic before the mites re-enter the cells to breed again). Based on this assumption, an average drop rate of 2 mites per day ought to correspond to somewhere between 10-14 phoretic mites.

I also dusted with PS sugar today and the result was a 2h PS dust drop of 6 mites. Another 1 or 2 mites should drop due to the PS over the next 22h and assuming that the 24h PS dust drop corrsponds to roughly 50% of the phoretic mites, this wuld correspond to somewhere between 14-16 phoretic mites, so the two estimation techniques are pretty close and both indicate that the number of phoretic mites in the hive was in the range of 15 before I knocked them down with PS dusting in the range of 7-8. If all of these estimates are correct, I would expect another 2 phoretic mites to emerge overnight (as well as 2 falling naturally) so that the resulting number of phoretic mites tomorrow oght to be in the range of 9-10 and if I can dust again, I ought to see 4-5 mites drop from PS in 24h...

I'll keep monitoring on warm days and see how this assessment hold up, but my feeling right now is that I have largely saved this hive from mites and PMS and now I have other problems to worry about.

I basically have a nucs-worth of bees in a full deep and they are unable to keep the hive chamber warm enough in all of the rain and damp we are getting, so I am starting to get mold growing on the outer frames.

Tomorrow I plan to move this hive into a nuc box where hopefully they can continue to recover more effectively in a more manageable space.

Will continue to post updates as I have anything to report.

-fafrd

[fafrd]

For those following my progress with this recovered hive, here is a quick follow-up:

I checked for more mites 24h after dusting on the 4th and there were none (so the 24h PS dusting drop on January 4th was a total of 6 mites).

I also dusted again on the 5th and the 24h PS dusting drop was 3 mites in the first 1 hour and another 1 mite in the subsequent 23 hourse (4 mites total in 24 hours post-dusting).

I've moved the cluster to a nuc box so hopefully they will be able to combat the mold more effectively.

I will continue to monitor natural mite fall but am going to hold off dusting any more for at least 3-4 days - dusting with PS to catch fewer than 5 mites does not see worth the trouble and I can probably catch the same number of mites total with less frequent dusting.

Every indication I have is that this hive/nuc now has fewe than 50 mites total (10-15 phoretic mites before they are dusted off) and about 26-35 foundress mites in capped brood cells (2-3 per day).

I still have work to do to save this hive given its reduced size, but I believe the severe fall 2010 mite infestation has been successfully beaten back. I will continue to monitor mite levels throuh naturalmite drop and follow-up with an update only when ther is anything significant o report.


-fafrd