Just wanted to comment that I really appreciate this information- fascinating stuff trying to correlate mite loads to long-term survival. While I have just started trying to keep systematic records of mite drops at regular intervals, it is sobering to note that it might not be easy (even long-term) to see any particular straight-line trends emerge between relative mite load and colony success.
Enjoyed reading the dialogue, though I had to read through both of your posts a few times each to feel confident I had taken it all in.
Sampling may be scientific methodology but I think interpreting the results is an art form! So many possible parameters to consider.
Have a great weekend.
Checked on one of my nuc sites. This is the one I had some hives starve. I think of the 30 I had out there, only one was an obvious deadout because of small fall size. The starve outs were definitely that. Some had a bit of stores below, but the boxes the clusters were in were devoid of stores. If February wasn't so cold, I could have done much better, probably close to 90 % survival like my other nuc site. Some of the late starts I assumed would need help and put a feeding rim with 3.5 kg of fondant right on the cluster at the beginning of winter Of these, 6 of 7 made it with small spring clusters, but all with brood. Some could use a shake or so of nurse bees, but will probably build on their own if left to their own devices. I looked at the bottom boards of the dead outs and found only a few mites. Reduced the box number on a couple of nucs that were not strong enough to take care of their winter set up. I did give one nuc a shake of bees. Kind of half heartedly as this was a strong nuc going into fall. With the number of hives I have, it may be better to let nature do its work. Its sister going gangbusters next door on 12 frames. Pollen coming in and brood present on all remaining 17 nucs.
So queen rearing season begins. I placed my first batch of cells yesterday and will place another batch a week from now. Will place about 20 a week and be done placing cells half way through June, depending on the interest in my nucs. Almost all my hives are in their permanent locations. Just some dribs and drabs left. Almost all overwintered nucs have been placed in big boxes. I am still making them like a banshee. I installed a new site which s about 1/3 full already.
The bees are really taking off. Even the weak sisters last put in big boxes have 5 frames of brood. I will have trouble keeping up to them. It was so nice to have lots of bees to work with making up nucs. I put so much strain on one site last year, draining them of bees.
So my strategy this year is to use strong hives with early fall brood mite counts of less than 10 percent and survive at least 2 years. My longest surviving hive was at 8 percent for perspective. She is doing well this year. My strongest 2 year survivor had a mite count of about 15 percent. I have a few in the 2/3/4 percent, and these will be over represented in the queen rearing. I will be requeening hives with counts over 20 percent. Nature has already taken some of these out of the equation this spring, and I don't believe there is a strong hive with fall mites counts in this range. There was one, but the queen disappeared with no brood. I will simply kill the queen, come by at 9 days and destroy all the queen cells and give them a frame of open brood from a good hive. An extra long brood break.
So there may be a 2 yr threshold resolving for my location for thriving bees. It is probably around 15 percent fall brood count. My medium term goal is to shift the distribution curve to be mostly under 10 percent. It is interesting to see how the genetics of poor hives is weeded out by nature over time. Death isn't necessarily needed. Weakened hives do not reproduce or put out very many drones. There were also failures at lower mite counts. I believe there is more going on than mites, and these failures indicate susceptibility to other factors such as viruses. I have an article in progress, and when it is published at will provide a more complete data set and outcomes here.
Just as a casual observation I am observing some chewed out drone brood. Indication of bees at work.
Excellent post. I apprecaited reading the specific matrices that you have developed for evaluating your propagation efforts- that is a very helpful jumping-off spot for those of us who are not yet at the point of moving past survival.
I also look forward to reading your article, and I assume you will be kind enough to post it here?
Thanks again for the update and the selection details- very helpful.
Have a great day.
I think the mite counting and tracking outcomes is proving useful. My writing is not the best so the editor will have to wrestle it into some sort of shape. May take some time. I will post a link.
Have you heard of the work of Eric Erickson in Arizona? There is something about his work in American Bee Journal 8/2000.
I have read about him only through some articles by Erik Österlund.
One is here: http://naturligbiodling.eu/blogg/?p=520
When he started his threshold was 15, then was dropped to 10 and after 6 years it was max 6-7%.
This relates very well what I have discovered.
Last edited by Juhani Lunden; 05-08-2019 at 11:37 PM.
I haven't heard of his work. I will do some reading.
How and when do you do your mite counts Juhani? I would guess that a brood count could be different than one taken from adult bees. In theory, with reduced brood nests in early fall, a brood count could be higher than an adult count. Then there were hives with such terrible brood that no brood sample was taken. The adult bee population was ok but I didn't think much of their chances. These all seem to be doing well this spring. I suspect a mite murdering spree was in progress. So many questions...
so far I haven't encountered this but my n is far less than yours. Two years ago the bee inspector did sugar shakes about this time of year and found my mites were only slightly above other operations in the area. My highest was about 3% and that colony died the following winter. I can imagine scenarios like the one you mentioned. I think I have seen my bees do a concerted effort of mite killing in an episode at the time of last years sampling. Very little brood and what there was, was very spotty. No sample to be taken. Yet those colonies were strong this spring. Hope to have a fairly complete description of mite dynamics in my system over time. This spring will do a few comparisons of low and high fall mite colonies to see what they did with the mites over winter. And I should look at the no sample colonies.
I was placing some queen cells today at one of my sites. Since I was there I tried to find and kill a queen of a hive that had a 30 plus percent brood mite count last fall. I couldn't find her, but since I was there I took a brood sample to have a look.
This hive started slow but seems to be picking up steam. It was a good honey producer last year.
So I won't be coy and ask for predictions, but I am wondering if a few could pause a bit, make a prediction before reading the result and post it.
I counted 100 pink eyed pupae and found 0 mites. Must be all in the drone brood.
very cool lharder. did you change your mind about requeening that one?
journaling the growth of a (mite) treatment free apiary started in 2010. 20+/- hives
you can call me Leroy.
Re requeening, confused and a bit dazed. Don't know