OH, I am a fan of both of the Ellises I find both of them very objective.
OH, I am a fan of both of the Ellises I find both of them very objective.
Yeah, but HIVE+ and I have been having a PM discussion about methods, so getting in to the papers from formal studies helps us decide which methods we can actually handle. Maybe I can't evaluate correlation between hygienic behavior and certain volatile compounds emitted by dead pupae, because I don't have GC/MS, but I can certainly build the cages from wood and hardware cloth used in this study by the same guys who did the heavy sugar study above.
"A strategy for using powdered sugar to reduce varroa populations in honey bee colonies"
Determining varroa on capped brood is best done by sacrificing the brood, but that's what you do with the drone brood strategy anyway. Instead of feeding the brood to the chickens, evidently you drown them in alcohol to kill and dislodge mites (at least, that's what these researchers do with samples of adults). A mason jar of moonshine ... uh, I mean denatured alcohol is evidently good enough labware. Hey, drones either get kicked out to starve or die the first time they have sex. Maybe drowning in booze is not a bad option.
A perfect example of my point: the whole idea of "heavy" treatments with powdered sugar is a moot point. Experience already tells us powdered sugar is dusted on, Thomas Dowda's method perfected by Dennis Murrell. Always worked for me anywhere there are mites. Why? It removes mites from the colony when a mite count tells you the hive is approaching the economic threshold. Removing mites DECREASES the mite load. This combined with drone culling works anywhere. Brood is usually covered with bees anyway and the benefit exponentially out weighs the risk and as you pointed out drones are a dime a dozen.
Not saying stop reading journals, just don't blanket apply them without observing and adjusting. Environmental differenced require it.
Like I said, I'm more interested in the methods. Some of you guys already know these tricks but I'm scrambling to learn. Ferinstance, Mr. Bush mentioned an alcohol wash and I was not familiar with it. But one of the papers used the method, described what they were looking for, and now I know it is not some benevolent way of getting you bees all nice and clean and refreshed. But it gives the ability to count mites accurately on a sample of unfortunate bees, when otherwise you'd hardly spot any by just eyeballing frames.
If I want to study one of these factors that has not been looked at yet, I need to learn these methods.
Whatever I can learn hanging around this forum, or in bee class, or from a soon-to-be-assigned mentor is great as well. Fact is, I'm wallowing in this stuff and can't wait for mid-April when we pick up our nucs. Sorry, Duncan, I can't learn from my bees yet 'cause all I got is a couple of empty 8-frame hives. So instead I'm hitting the books, etc, and getting the stuff ready to go. Really pretty paint job on my supers, though.
If I freeze drone brood I will have already done the murder ... might as well count the mites. I don't have chickens or a fish pond as some have suggested, and the last time I tried feeding bark beetle larvae to the birds, the ants got 'em first.
Sorry I assumed.....But you are in for a fascinating ride. Good luck and be ready to report your observations because any one of us can learn something new, you may be the one who sees something I did not. HAVE FUN!!!!!!!
Trying to attach a photo we took of mite infested drone brood.
The section I removed was the only drone comb I saw and there had to be at least 300 mites in that section of about 150 cells with an estimated 90% infestation rate.Thanks jfb58 for the numbers. I've been curious to what extend varroa prefers drones. There are summaries of numbers that come up when I do web searches, but I'm digging deeper to find the context for those numbers.I did a count, had 7 mites on 203 nurse bees, 3.5%. These are locally adapted survivors from a swarm trap collected 6 months ago: not too bad to work with, but they were plenty p-o'ed when I brushed off a brood comb. This isn't my only hive, and no monetary risk, seems like a good opportunity to watch and see what happens. Mr. Bush, I look forward to meeting you in Arizona next month, hope you are still coming!
My current situation is similar to yours. Drone production is dwindling right now. I uncapped the small patch of remaining drones and found maybe 50-66% infested, often with multiple foundresses. As drone production dwindles do pretty much all remaining drone cells get infected?
About a month ago I did a full colony sugar dusting after a drone comb emerged and about 35 mites dropped. I sugared them twice since then and got little to no drop. Yesterday, after uncapping the highly infected drones, a full colony sugar dusting yielded 1 mite.
So it's hard for me to correlate any sense of the two measurements without assuming almost all the mites were in the drone comb. Maybe I do have to do a sugar roll of nurse bees, or protect my bottom board from ants, to get a broader picture of the infestation % situation.
What it may demonstrate is that sugar dusting doesn't really get them.
Last edited by BeekeepingIsGood; 08-17-2015 at 03:21 PM.
I find sugar dusting does a good job on broodless colonies also.
SO if I don't have much drone brood, sugar shake should help get some of the mites out.
Started 9/13, building slowly, now @ 12 Lang hives and no treatment yet
To answer that, goes like this.
First re drone brood, even in a hive with a natural amount of drone brood, about 40% of mites in brood will be in the drone brood, and about 60% in the worker brood, or at least that's what was found when someone counted them all. Of course the ones in the drone brood produce more offspring due to the longer pupal stage.
But in any average hive around 80% of mites are inside brood cells, and around 20% walking around on bees (phoretic). So if a sugar dust is done, only around 20% of the mites are available to be contacted by the sugar. Of that 20%, only a small % of those, are actually dislodged, and this can be demonstrated by doing an alcohol wash of a bee sample immediately after a sugar dust to see what was missed by the sugar dust.
Because of the way mite populations expand exponentially, often a mite population can be right back, or past where it was, very soon after a sugar dust.
However people still think it works, because they do a sugar dust and find some mites afterwards, so therefore it "worked". Many do not consider that finding 100 mites is not going to do much good if the mite population of a hive is 2000, which it easily can be. A better test than seeing how many mites dropped without knowing the total population, would be to see where the hive is a few months later.
In this context, I'm mainly looking at it to provide some indication of overall infestation levels. The problem is on 3 of 4 occasions virtually no mites dropped. Even if we extremely low-balled sugar dusting as only dropping 1% of the phoretic mites(20% of the overall mite pop.), and guess that despite seeing 66% infestation in the drone comb there's only a 9% total infestation, I'd still expect 14 mites drop in a hive of 80 000 bees. If we use Randy's 40% figure then I should being seeing 576 mites drop.However people still think it works, because they do a sugar dust and find some mites afterwards, so therefore it "worked".
Perhaps there's something else at play here? The reason why I peeked in the drone brood in the first place was because I saw an undeveloped worked getting pulled out of the entrance.
A small percent. Those that have found it useful were doing it at high frequencies before a serious mite problem developed, or during broodless periods. These are my notes on sugar dusting varroa.SO if I don't have much drone brood, sugar shake should help get some of the mites out.
Last edited by BeekeepingIsGood; 08-18-2015 at 11:57 AM.
Yes agree. Based on your best case, and worst case calculations, you should have seen minimum 14 mite drop, and maximum 576. But "The problem is on 3 of 4 occasions virtually no mites dropped".
Which demonstrates that sugar dusting is not effective, or at least not reliable. That's the something else that's at play.
Having said all that, if someone wants to sugar dust I have no issues with it, other than it can damage young larvae although they can be quickly replaced with minimal loss to the hive, and don't rely on it to rid your hive of mites.
I will acknowledge this as a possibility, but I don't have any reason to believe absolutely that it's so incredibly ineffective.Which demonstrates that sugar dusting is not effective, or at least not reliable.
There was a unique situation with 1 of 4 times that the sugar dusting did show a drop with this hive. Given the information available, I don't see why a low overall mite infestation in spite of the heavy drone infestation is not equally plausible.