I imagine that the same pheromones that attract varroa to drone brood also have some significant meaning to bees. Indiscriminate use of a synthetic version of the pheromone might prove confusing, perhaps convincing the bees that the queen is laying an undue quantity of drone eggs. If so, there may be an increased rate of supersedure. It will be interesting to find out the results of the research that Tom mentioned. Mike Swintosky Dellroy, OH