Mon, 15 Aug 2005 Dick Marron said: My friend from Germany wants to know why we are still talking about liquid treatments with O/A when it is so easy to sublimate. and: Mon, 15 Aug 2005 Bill Truesdell said: I would definitely go the vaporizer route, in spite of its additional hazards (dealing with a corrosive vapor). Hallo all, Russians has been dealing with oxalic acid long time before West Europeans (1980's, than USSR). Their primary recommendations, regarding metod of application, were vaporizing (sublimation) and spraying (late 1980's). In those times they did little research on dripping method. They did not recommend OA in our days. I suspect that they use it, but not on large scale. Why? Yes, there is a some anegdotal reports of varroa resistance to OA. But... Primary reason is special beekeepers desease (attack: kidney, result: stones). (We are talking of long term exposure!) Why sublimation metod is not recommended? Because it leaves (contaminates) around 60% of OA crystals distributed at all surfaces of hive (inside)! (After sublimation 40-60% of acid will return in crystalline form) There is no way for bees to clean the hive 100% in short time (it is just opposite, they avoid it, because it is too acidic for them), and there is no way for beekeeper to not catch some OA crystals on his skin - even if he is using gloves all the time. OA crystals in dry and dark conditions can be "active" long time. That's why beekeepers use twice smaller quantity of OA dihydrate, when they use sublimation metod, and why this method is much better for varroa kill, but... Regards, Aleksandar Mihajlovski Macedonian beekeeping journal: "Melitagora" :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and other info --- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::