Shrivelled wings

[sean-a]

I spotted a solitary bee with shrivelled wings in one of the hives yestereday.
I have treated a couple of times early this spring with OA and had no mite drop, so either I didnt do it properly or there is a very low Varroa population.

Should I be worried?

 

[mjt68]

I spotted a solitary bee with shrivelled wings in one of the hives yestereday.
I have treated a couple of times early this spring with OA and had no mite drop, so either I didnt do it properly or there is a very low Varroa population.

Should I be worried?

What is your current mite count? One bee could just be a developmental abnormality.

 

[charlievictorbravo]

Deformed Wing Virus existed before Varroa mites came to the UK. Although Varroa have made the transmission of viruses easier (for the viruses), without the mites, the DWV would still exist on a smaller scale.

Maybe you've got non-varroa-transmitted DWV.

CVB

 

[B+.]

Should I be worried?

You are describing Diseased Wing Virus (DWV).
Although you may have only seen a single bee which is expressing the condition currently, there are very likely to be more (or will be).
It affects both workers and drones. Varroa mites are a vector of the virus so, if you can keep the mite infestation low, you should be able to reduce (but probably not eliminate) the condition.
OA sublimation only affects phoretic mites (i.e. those travelling on the adult bee) and doesn't affect reproducing mites that are sealed in the cells. This is why advocates of this method treat 3 times 5 days apart. It is believed that this will catch varroa as they emerge from the cell with the adult bee. It is also recommended that such treatments are applied during periods when there is little/no sealed brood i.e. winter.
Another approach is to use bees that naturally seek out reproducing varroa mites in the cell and disrupt their breeding pattern by uncapping and removing the pupae (VSH). It is still very early days for this approach and, at best, it can only disrupt the breeding pattern during periods when the mites population is expanding so it is not a complete solution in itself.