Comparing varroa drop in your colonies

[user 20297]

Until my recent splits I haven't had much opportunity to compare the behaviour and other attributes of colonies of bees. But since a split I now have more colonies to study.

The recent swarm colony from an original, untreated hive of mine is dropping about ten varroa per day......which seems a bit scary. The parent colony, now headed with a cast queen, who stayed in residence without swarming, is dropping zero mites per day. The colony with the original 2020 queen of the parent-hive drops about two mites per day. All the colonies are thriving, with lots of healthy and evenly laid brood. But the varroa-infested one is doing best from relatively the worst starting point.....no brood, no food, no organised hive.

I have come to the conclusion that varroa drop to a removable board can be a good indicator of relative levels of varroa as long as all my hives have a board in all of the time and as long as I check them daily.

Being obsessed with my bees this is easy for me although I am aware that many people wouldn't leave the board in place and couldn't check it daily in any case. A few days ago I nearly decided it was time to grow up and get vaping. But I held my cool and the drop has reduced a little.

I hate the idea of any kind of varroa monitoring which involves killing or excessive handling of bees, so this comparative observation, although hardly a disciplined technique, gives me some idea of the state of colony infestation. I'm wondering if anyone else has seen varroa infestation fluctuate negatively by literally keeping their OA powder dry?

 

[pargyle]

Yes ... I've been testing for varroa for the whole of the time I've been keeping .. but for the most part I do sugar rolls which are far more accurate than the inspection board. I've seen some massive spikes in colonies which have subsided fairly quickly but I still live with the fear that one of these days the mite load is not going to go down. Of late in all my colonies the mite load has been consistently low - whether the conditions in my locality, whether the way I keep my bees, whether my bees have found ways of coping, whether my insulated hives contribute to the low levels of mites or whether I am just lucky - I don't know. Whatever it is my bees appear to survive and thrive without treatment - I am grateful for that - would I recommend it to anyone else ... probably not when OA by sublimation is available. If generic OA was made legal for sublimation - definitely not.

 

[user 20297]

Thank-you for a balanced response.

Yes ... I've been testing for varroa for the whole of the time I've been keeping .. but for the most part I do sugar rolls which are far more accurate than the inspection board.

I think that an active examination such as that is likely to be more accurate, but I'm making the point that comparative, natural drop observations done regularly may be a fairly good indicator of varroa infestation.

I've seen some massive spikes in colonies which have subsided fairly quickly but I still live with the fear that one of these days the mite load is not going to go down. Of late in all my colonies the mite load has been consistently low - whether the conditions in my locality, whether the way I keep my bees, whether my bees have found ways of coping, whether my insulated hives contribute to the low levels of mites or whether I am just lucky -

I think that with all the positive actions you've done...the least likely factor to have been the reason for your low varroa levels is the one highlighted. It's also good that you don't put emphasis on the bees having some special superpowers.

 

[pargyle]

I'm prepared to accept lucky ... altough ... there are a number of non-treaters in the area who also appear to be 'lucky' and a large number of treaters who, judging by their winter colony losses, appear to be very unlucky ... does make you wonder what's going on ? And I have no idea - I just keep doing what I've been doing ...

 

[Erichalfbee]

I'm making the point that comparative, natural drop observations done regularly may be a fairly good indicator of varroa infestation.

Natural drop is ok provided no varroa are scavenged from the inspection tray and that it remains in place for an entire brood cycle of 24 days. Not extrapolated from a weeks count.

 

[user 20297]

Natural drop is ok provided no varroa are scavenged from the inspection tray and that it remains in place for an entire brood cycle of 24 days. Not extrapolated from a weeks count.

My analysis comes from being so obsessed that I'm assessing it every day on every hive....with "3 hives and a few more" , that's fun for me; but I realise that it's hardly practical for most normal people.

 

[user 20297]

I'm prepared to accept lucky ... altough ... there are a number of non-treaters in the area who also appear to be 'lucky' and a large number of treaters who, judging by their winter colony losses, appear to be very unlucky ... does make you wonder what's going on ? And I have no idea - I just keep doing what I've been doing ...

As you imply and have proven....luck doesn't play the biggest part in keeping bees. Whether you treat them or don't treat, you can have really bad luck. But whatever management technique you choose, as long as healthy bees rather than dead varroa mites are the focus of your travails, the bees will be better equipped to deal with all of the variables.

 

[Levitt53]

Well just to join this polite conversation. Personally I don't treat mine and I don't monitor at all and in the last few years I have only had one colony that I would say had failed to thrive due to varroa. My queens are all fairly dark. Whether I am lucky or it's their genetics or bees have worked out this hygienic behaviour I don't know. What I would say is that it makes the whole beekeeping lark a whole lot easier.

 

[user 20297]

What I would say is that it makes the whole beekeeping lark a whole lot easier.

......well, it becomes beekeeping rather than a varroa eradication competition, doesn't it.?

 

[B+.]

Natural drop is ok provided no varroa are scavenged from the inspection tray and that it remains in place for an entire brood cycle of 24 days. Not extrapolated from a weeks count.

Natural mite drop is only reliable in the early part of the year. Once they start brooding, it's not even a reliable relative indicator as you don't know how many are reproducing inside sealed cells. A better approach at this time of year is to take 50g samples of workers from the supers, freeze them overnight to kill the bees (I use chlorophorm in a killing jar which is quicker) then wash the mites in a soapy water solution to dislodge the mites and strain them into a honey strainer. If you plot the number of mites per 10g over the course of the season, you can track the growth in the mite population much more accurately.

 

[Erichalfbee]

Natural mite drop is only reliable in the early part of the year. Once they start brooding, it's not even a reliable relative indicator as you don't know how many are reproducing inside sealed cells. A better approach at this time of year is to take 50g samples of workers from the supers, freeze them overnight to kill the bees (I use chlorophorm in a killing jar which is quicker) then wash the mites in a soapy water solution to dislodge the mites and strain them into a honey strainer. If you plot the number of mites per 10g over the course of the season, you can track the growth in the mite population much more accurately.

Thanks B+ that’s much clearer thank you