Counting Verroa in drone brood

[Elaine]

I am trying to establish the level of verroa infestation - there are usually no verroa on the (solid) floors of the hive. I do NOT take this as an indication that they are not there! The bees keep the floors spotless - no cappings, bits of bee etc to be seen, but it does mean I have nothing to count

The only verroa control I have done this year is the removal of some free comb with capped drone cells. This I froze, and then opened up the cells to see if there was verroa inside. Problem I have now, is knowing what these counts mean! Does anyone know if there has been any research in extrapolating percentage of infected drone cells to level of problem in a hive?

These hives are all the result of splits or swarms, and have had brood breaks, and at every inspection I look closely for DWV - and have only ever seen the ocaisional bee with deformed wings.

I am still trying to decide how I want to treat this autumn/winter. As we have heather nearby, nectar is still coming in, so I don't have to make an immediate decision, but do need to bear in mind the temperatures if I am going to treat with one of the proprietry products.

I am still trying to decide how I want to treat this autumn/winter.

 

[Luka22]

Hi,

I don't have an answer for you, but got a similar issue. I hardly ever saw Varroa, just from time to time I can could see a Mite sitting on a Bee, so nothing too bad I thought.

Last Sunday than I inspected and found 2 Frames in the Super with Drone Cells. Strange enough, because we use a Excluder, so we assumed that this was a worker. The Queen only hatched about 3 weeks ago, but is laying already so no issue on that part, anyway we removed the 2 Frames with the Drone Cells, must have been around 100-200 of them and we thought its a good chance to check for Varrora as we read somewhere to check on Drone Cells. And yes, we had in nearly every cell Varrora, some Larvae was just mashed up, I guess that is what Varrora does? We stopped counting on around 80, as said, some had nothing, others could be 2 in it.

What does that mean now? Do we have a serious problem or is this normal?

Sorry for taking your post for this question, but answers on either your or my issue might help both of us.

 

[jackbee]

Beebase varroa calculator - https://secure.fera.defra.gov.uk/beebase/public/BeeDiseases/varroaCalculator.cfm

 

[alanf]

Quote from a bee inspector asked the question was that if your drone cells are showing more than 15% cells with varroa you should be planning to treat soon. Count the cells with one or more as a percentage of the sample, not the total varroa count. The calculator (as linked above) gives a rough estimate of numbers.

 

[Elaine]

Hi - thanks for the pointer, I looked at this, and it seems to err very much on the side of caution, with very big ranges of indicated infestation, and warnings regarding amount of drone brood being outsidethe norm for this time of year - giving me an outcome of treat between 0 and 8 months

 

[itma]

... I hardly ever saw Varroa, just from time to time I can could see a Mite sitting on a Bee, so nothing too bad I thought.


... anyway we removed the 2 Frames with the Drone Cells, must have been around 100-200 of them and we thought its a good chance to check for Varrora as we read somewhere to check on Drone Cells. And yes, we had in nearly every cell Varrora, ...

If you actually see mites on bees, the strong probability is that it is actually rather a BAD sign.

While not in itself a signal to treat instantly, it is certainly a signal to promptly CHECK (as carefully as you can) by the recognised means, whether or not the infestation has reached problematic levels.

 

[mbc]

I find it easier to count in binary ( 1 or 0 ), a very slight infection (~1 or 2 varroa in several forkfulls) or no varroa = 0 and anything above = 1 and needs treating at some point.