Topic: Varroa Treatments for Honeybees

[bombus]

What Varroa treatment will you be useing this year? :-\

[Robert_Brenchley]

I just treated with oxalic acid. It was probably superfluous since I had a massive influx of the horrible things last autumn, presumably from collapsing hives, since I know there were a lot of colonies lost in the area. I did an emergency treatment with Apiguard, and only lost one hive out of the three. But I particularly want to be sure of starting this season with a very low mite count, as I've been having trouble with queen mating. I'm pretty sure that this is due to a lack of viable drones, which seems to be the usual cause, once you've eliminated strains where the virgins won't fly in anything but perfect weather. There's some evidence that parasitised drones may not be able to catch a queen, and as varroa prefer drones, I want to be sure that there are next to none, so I can see whether it makes a difference.

[bombus]

Hi Robert, What method are you using to administer it? I'm thinking of using it myself this time. I'm been monitoring mine and at the moment they seem  OK,but I'm hearing of a lot of resistant mites in the county.

[Robert_Brenchley]

I trickle it; I won't use vapour as I'm not convinced it's safe. You use 7.5g of oxalic crystals, 100g of sugar, and 100ml of water, mixed up, and trickled on (I use a syringe out of an old injet refill kit) at 5ml per seam. Use it when the hives are as near broodless as possible; normally this will be about New Year, though there are several months over winter when there won't be enough brood to make any difference.

There have been a lot of hives dying out round here over the last season, hence my problems, and I'm pretty sure resistant mites have arrived unnoticed, wiping out the 'rote' beekeepers. The answer is not to use fluvalinate.

[bombus]

I understand that Thornes are awaiting delivery of a ready prepared oxalic acid based product. I think i will be using it this year.
Did your Bees tolerate it ok, i suppose you could use it warmed up.

[Robert_Brenchley]

I haven't had any problems with tolerance. It does some damage, and you can't trickle more than once in a bee generation or it starts doing real harm. The problem, of course, is that bees and varroa are sufficiciently similar that anything which kills one will inevitably do some harm to the other. The real problems arise when the poison is persistent in wax like fluvalinate is. Allegedly, oxalic vapour can be used repeatedly within a single generation, but it's what it may be doing to the beekeeper's lungs that worries me.

I don't bother warming it up. I just lift off everything above the broodnest, and trickle it into the seams. It causes minimal disturbance, and doesn't seem to bother the bees.