Varroa drop in February

[beeno]

Go right ahead. You're welcome to try.

Not me I certainly don't have the knowledge, the facilities or the amount of bees required, but that would be an interesting research project for someone.

 

[B+.]

I have no idea how you find these things Beeno but this article is quite interesting Reproductive parameters of female Varroa destructor and the impact of mating in worker brood of Apis mellifera
The implication is that the anywhere between the 5 to 20% of mites not in brood cells that are infertile are still capable of reproduction

They're able to produce male varroa which die in the cell without females to mate with (unless there are multiple foundress mites in a cell). Most beekeepers are concerned with the growth in varroa populations within their hives.
In VSH/SMR testing, we consider varroa that produce a male and protonymphs/deutonymphs at the purple-eyed pupa stage as non-reproducing as the varroa mite would die when the honeybee emerged.

 

[Erichalfbee]

They're able to produce male varroa which die in the cell without females to mate with (unless there are multiple foundress mites in a cell). Most beekeepers are concerned with the growth in varroa populations within their hives.
In VSH/SMR testing, we consider varroa that produce a male and protonymphs/deutonymphs at the purple-eyed pupa stage as non-reproducing as the varroa mite would die when the honeybee emerged.

The paper says they can mate with the male mite they produce. Ie their son. Then go on to produce females. Now how long does the male mite live? Not long enough to mate with the female varroa I presume?

 

[B+.]

The paper says they can mate with the male mite they produce. Ie their son. Then go on to produce females. Now how long does the male mite live? Not long enough to mate with the female varroa I presume?

Yes. I suppose that is theoretically possible but the male would die when the bee emerged from its cell and the female wouldn't live long either.
The point about SMR/VSH is that they target reproducing varroa in the cells and don't remove healthy pupae. Usually, we don't even find a male. I have seen lots of cells where the foundress goes into the cell and dies without even producing a male

 

[North End Bees]

Yes. I suppose that is theoretically possible but the male would die when the bee emerged from its cell and the female wouldn't live long either.
The point about SMR/VSH is that they target reproducing varroa in the cells and don't remove healthy pupae. Usually, we don't even find a male. I have seen lots of cells where the foundress goes into the cell and dies without even producing a male

But it's not just theoretically possible. The paper shows that it happens in actual practice, both in natural and artificially introduced cells. The immature females are able to survive eclosion of the bee and reinfest another larva.
Towards the end of the paper they report that these females lose one brood cycle (while mating with their son) so instead of having the average 2-3 mating cycles, they have 1-2. Enough to increase numbers exponentially.

I don't doubt you're right that this may not happen with SMR/VSH bees, but the general discussion is about 'ordinary' bees.