In message <[log in to unmask]>, "Allen G. Meek" <[log in to unmask]> writes >As a new hobby beekeeper I have questions about Apistan. Where to start! Apistan is a strip impregnated with a synthetic pyrethroid known as tau-fluvalinate. It is designed to dispense the compound by contact with it, as you say, it rubs off. The particular formulation of the chemical used is not really soluble in water (and so honey) but is partly soluble in wax. Some studies have shown that honey in contact with wax for a long time can become contaminated with fluvalinates but so far a different preparation of the chemical (eg.Mavrik) has been responsible. As a beekeeper therefore your concern is to limit the residue in wax. There is a problem in that the residue becomes locked into the wax (rather like in the strips) and so will not be exposed to UV light which would eventually break it down, or transported around. So it doesn't breakdown, isn't effective and it's an unlikely souce of aquired immunity. We know from research that in the main the residue is found near where the strips were placed and the reason supers are left off is to prevent the compound being incorporated into the newly constructed wax, rather than control its transfer to honey. Confining the bees and chemical to the brood will also improve the efficiency with which its dispersed. Control of the dose is very important because of the strategy we need to use to delay the probability of suceeding mite generations reproducing a chance resistance to the chemical. I find the genetics of this rather trickey so get someone else to explain that one. The upshot is that you follow the instructions, use them and then take them out. A good summary of the technical and toxicological data available for the compound can be found at <http://ace.ace.orst.edu/info/extonet/ghindex.h tml> and doing a search for 'fluvalinate'. As far as I know the most significant risk to human health is the chance of some hypersensitive people developing a skin rash so Sandoz suggest gloves! -- Dave Black Blacks Bee Gardens, Guildford, GU1 4RN. UK.