Apistan has a limited effect on tracheal mites, certainly not a high enough efficacy for control. Tau-fluvalinate has a very low vapour pressure, it works by contact action. For tracheal mite control you need something which can permeate the trachae of the bees, ie a gas or vapour. Apistan will not cut it, as it was not designed for that target. However, the new product which Vita is currently submitting for registration in Europe seems to be much more effective against acarine, as well as varroa - the main target. I'll keep you informed as we get more data. Max Vita (Europe) Limited ______________________________ Reply Separator _________________________________ Subject: Apistan and *Tracheal Mites* Author: [log in to unmask] at INTERNET1 Date: 8/14/97 6:28 AM I've been wondering: Apistan works on varroa when they are outside the cell -- the so called phoretic state. Fluvalinate is hard on varroa, but has relatively little effect on the bees. Here's the question: Tracheal mites have to spend time outside the bee in order to transfer to other (younger) bees. In such a state, are they susceptible to some extent to Apistan (R), or are they -- like the honeybee -- somewhat fluvalinate tolerant? Allen