Hi Lloyd, I agree with what you're saying but Tony is talking about Bayvarol in the UK. It's different from Apistan and the kill profile is not quite the same. I don't have the Bayer figures but I'm pretty sure the % mite drop is slower than for Apistan. In message <[log in to unmask]>, Lloyd Spear <[log in to unmask]> writes >Tony Bloor asked about mites and strips. > >My understanding from a lecture just last week by Dr. Nick Calderone of >Cornell, is that approximately 50% of the adult mites will be killed in the >first 48 hours by the strips. The remainder will be killed over the next >several days, but the percentage is difficult to determine as the kill will >also include those emerging from cells. >Yes, your mite infestation is very low. >I have not heard of mite resistance in the UK. That doesn't mean it is not >there. If you leave the strips in for the recommended length of time you >will get a 99% kill, if you do not have resistance. It is not 100% only >because some mites seem to escape the fluvalinate. Unless resistance is >present, even those 1% would be killed upon exposure. However, at the end >of the 6-8 week time, the amount of chemical on the strips is very low. >Keeping them in the hive beyond then will eventually lead to resistant mites >as the chemical load on the strips is not enough to kill them, allowing them >to build a tolerance. >I hope this helps. -- Dr Max Watkins