Andreas say : > I am relatively new to treating varroa and I need somebody's experienced > comments on the concentrations of fluvalinate based drugs used in treating > varroa. > > What we have here (CYPRUS) is a drug called MAVRIK which if I am not wrong > indicates that it is 240gr/liter concentration. I was a bit sceptical in > using MAVRIK since on the label it said nothing about treating varroa and it > only gave concentrations for other (agricultural) uses. Fluvalinate (merck index 10th ed. no 4107; 11th ed. no 4137) : synthetic pyrethroid pesticide. Yellow-amber liquid. Vapor pressure : very low. Solub. in water : 2 ppb ... ! Thus : volatility very low, insoluble in water (and in honey) but soluble in the wax ! Used against varroa as plastic insert which contains 10 % of pure fluvalinate : trade mark APISTAN (Sandoz-Zoecon). The drug ooze slowly out of the plastic (very small cracks visible with electron microscope) and the bees are spreading it over the whole hive. The other fluvalinate mixtures (Klartan, Mavrik, ZR-3210) contain compounds which allow solubilization of the drug in the water and thus in the honey ... The use of these drugs is prohibited in beekeeping. N.B. to Andreas : I transmit your request to the Sandoz co which will answer directly your questions Regards Jean-Marie ----------------------------------------------------------------------------- Jean-Marie Van Dyck Fax +32 81 72 42 72 B.P. 102 email : [log in to unmask] B-5000 NAMUR(Belgium) Medical school - Biochemistry dept -----------------------------------------------------------------------------