I've seen a lot of colonies with Apistan hive strips installed, spring or fall, and the queen continuing to lay, apparently normally. That's not to say fluvalinate strips cannot harm queens, though. At the Canadian Apicultural Research Symposium last week in Edmonton, Dr Rob Currie of Manitoba reported a set of trials with Apistan queen tabs in queen cages. The details will be coming in a proceedings, but as I remember, adverse effects on queens were slight at three days of exposure, definite at seven days of exposure (the treatment min-max range). Effects were increase mortality (40 % at 7 days, compared to 10%) and possibly increased supercedure (but not statistically significant). Placement of the tab under the screen, rather than completely in the cage, resulted in slightly less effect. Only 1 of 151 varroa subjected to this treatment, survived. Kerry Clark, Apiculture Specialist B.C. Ministry of Agriculture 1201 103 Ave Dawson Creek B.C. V1G 4J2 CANADA Tel (604) 784-2225 fax (604) 784-2299 INTERNET [log in to unmask]