Oxalic Acid

[Susan]

Can you use oxalic acid in 90 degree weather? Just removed supers and moving to cotton and want to treat, but the next week will be in the mid 90's here. Any ideas?

[Bob Harrison]

It is my understanding if you use OA when brood is in the hive brood will be killed. I have never used OA but what others have said. Most have said they use OA in late October or November.

[Ross]

Yes you can. I don't believe the brood will be harmed particularly. The downside is capped brood harbor mites and the OA vapor can't reach them. Hence the desire to wait until brood production is at a low point. Most mites will be exposed to the vapor at that time.

[Bob Harrison]

You are using OA in 90F. temps without brood loss?
Are you using a vaporiser or drissling?

[Susan]

Thanks guys. We used it in April and no increase in brood kill. We are spraying it on. Just do not the same thing that happened last year. We lost about 30 percent from mites last summer. Think we will wait for now.

[Michael Bush]

I've used it in the early spring with brood in the hive and there seems to be some brood loss. That doesn't mean, if you have a severe infestation, that it might not be worth it. The other problem with doing with brood in the hive, is you'll have to treat three times a week apart to get the ones emerging from the cells. It might be less stress on the bees to confine the queen for 24 days (time for all the brood inlcuding drones to emerge) and then treat once.

I wouldn't worry about the temperatures. Mites fall and die more easily the hotter it is.