>I've looked through the archive here and couldn't really find a good comparison between all the different kinds of varroa treatments. Besides some being stronger and some being "organic", what are the real pros and cons for each one? And lets not talk sugar shake or home remedies, I'm curious about Checkmite+, Apistan, Apiguard, Surrocide, and the rest.http://www.bushfarms.com/beespests.htm#varroa
Most Varroa around here and elsewhere are resistant to Checkmite and Apistan. Apistan and Checkmite build up in the wax and make the drones sterile and the queens fail. So basically they no longer kill mites, but they will kill your hives and they have now contaminated the entire beeswax supply so all your foundation is contaminated. Fluvalinate (Apistan) reduces the immune system of the bees and it increases the reproductive rates of the Varroa that survive it. Checkmite at slightly higher than the levels lethal to mites, is lethal to bees and at slightly higher than those levels is a serious threat to human health. Enough so that at one time it was not allowed by the FDA in hives raising comb honey.
Several of the products (Apilife Var etc.) are thymol treatments. Thymol stinks, drives the bees out of the hives and is very temperature dependent. Assuming the right temperature etc. it will kill mites very nicely. Too cold and it doesn't work. Too hot and it runs the bees out of the hive. Thymol is a plant derivative (from the thyme plant). I'm sure there is SOME in thyme honey, but otherwise you would not find it in honey.
Formic acid is also very temperature dependent. Too hot or too much and it kills the queens. Too cold and it doesn't work. Just right, it's very effective. Formic acid occurs naturally to some extent in honey already. The commonly available commercial (not made for beekeeping) formic acid contains a lot of lead. The preparations being sold for beekeeping do not.
Oxalic acid vaporizers are not at all temperature dependent. If you follow the recommended dosage there is no problem killing queens and it is not hard on the bees. You can, in fact, treat once a week for several weeks with no noticeable decrease in the bees life. It is very inexpensive (enough to treat 100s of hives is available at the local hardware store as "wood bleach" for about $6). Oxalic acid is the sour in rhubarb and is that naturally occurring bite in honey. It is not approved as a treatment in the US. Since any pesticide requires someone to pay the cost of the research and the cost of the certification which must be periodically renewed, and since oxalic acid is readily available for $6 a tub, it seems very unlikely, given our approval system, that it will ever be approved and if it is it's unlikely anyone will be able to afford to keep the certification since cheap beekeepers will just buy wood bleach.
Oxalic acid dribble. This is very hard on the bees. It is not recommended to do it more than once as it shortens their lives considerably. There has been some speculation (and I think some research) that shows that it is hard on the bees kidneys or whatever organ it is that does that job in a bee. :) It's easy to do, cheap and effective. It is also not approved in the US.
I have not heard that Sucrocide is very effective from those using it.
All of these continue to propagate bees that cannot withstand the mites while favoring mites that reproduce like wildfire. :)
ALL treatments have this problem:http://www.bushfarms.com/beesvarroatreatments.htm
Which is the mathematical model for why you want to treat when there is no capped brood if you can.