The only registered (legal chemical) treatment for Varroa mites in the United
States at this time is Apistan strips (fluvalinate). Accordingly, Thymol is
presently "off limits" to U. S. beekeepers.
Hopefully one of the many alternatives to Apistan that I read about on Bee-L
will be registered in the U. S. very soon.
W. G. Miller
Gaithersburg MD