OAV For Mites

[Terri Yaki]

Should I gas my bees one more time? And if so, what temps are suitable?

[The15thMember]

In my experience, the best time to do OAV is when it's cold enough that the bees are not really flying, but warm enough that they aren't tightly clustered, and of course, when they have no brood.  So like 40-50F I feel like is a good temp.  Do you have screened bottom boards?  If so, what was their mite drop when you treated them the first time?

[Terri Yaki]

No screened bbs and failed to check on mite drop. So it sounds like a day when there are a few on the porch and they are using both entrances but nothing serious going on. Thanks.

[beesnweeds]

According to research above 32F for OAV and above 37F for OAD.  I've had to treat both ways below those temperatures (around 30F) and didn't have any issues.   It should be above 32F here by mid week to treat, if not I may treat anyway.

[Terri Yaki]

From what I've read, the only downside to OAV is the initial cost. If that is the case and nobody knows better, I'd err to the side of gassing vs not. But isn't that kind of cold to open up a hive for a drip?

[beesnweeds]

But isn't that kind of cold to open up a hive for a drip?

It takes less than a minute with no negative effects and if I waited until higher temperatures I would miss the window of opportunity to treat before the bees start brooding up. I use OAV now but would switch back to OAD if I ever had high Nosema spore counts.  There hasn't been any research that I know of on the effects of OAD on lowering Nosema or diseases but from what myself and others have reported is that is does seem to have an effect.

[Terri Yaki]

But doesn't the drip have a negative effect on the bees? From what I'm gathering, the short lived workers aren't so much the problem with that as it is with the queen, who we want to keep for a couple of years.

[beesnweeds]

But doesn't the drip have a negative effect on the bees?

Sure, if you mix it incorrectly.  Follow the instructions and use a 2.5% solution and you won't have any problems.  Mites and diseases will kill your winter bees and queens every time.  A weak solution of OA never will.