>It seems to me that if several different approved, proven, and available >treatments are out there, the best approach would be to develop a rotation >scheme similar to those available for treating worms (fly larvae) in >horses. By alternating between 2 or more treatments, resistance >development would be greatly delayed, since the pests would need to develop >resistance to both forms of treatment at once. Otherwise, those mites (and >their descendents) that survive one type of treatment would likely be wiped >out by the second type. One critical factor that you must take into consideration: Safety. Cumophos is being issued under emergency conditions to combat two specific problems. The small hive beetle being the major one, resistant mites a second. If you do not have either of these problems, then avoid the chemical. Here is something I think that should be said over and over until we all get it: Do not depend on 99.9% solutions. Use anything that helps. Here is some of the list I have been putting together: 1) Screened bottom boards. This puts a slow, steady drain on the mites population. A constant 5-10% killing of the adult mite population that will be very hard for the mites to develop resistance against. 2) Good ventilation. Mites that are not attached to a host have a short life. The screen board gets the ones that fall, good ventilation dries out those questing for a new host. Mites "leak" and the more air you move past them, the better the chances that they will dry up and die. Many other aspects of the hive benefit from good air flow so there is no need to debate this one. This also helps with the tracheal mites. 3) Fight stress in general. If one area of health is neglected then other attacks will do more damage. Do not forget that the tracheal mites are still there and continue to weaken the bees. By now almost all hives have them, do not forget the grease patties. If a colony is under stress watch close for brood problems such as EFB and treat fast. If a hive gets into trouble get the feed on it. Nothing is cheaper than a little 1:1 syrup for helping a stressed hive. 4) Always follow the label directions. Where the labels allow room, follow best practices. Adjust to your areas timing for honey flows and winter conditions. 5) Re queen any hive that stays a problem for too long. A marked queen from a quality breeder can make your beekeeping experience much more enjoyable. While I like my home grown queens, they are still the first generation of purchased queens. All of the larger producers are working with stock that is much more tolerant of the problems we are seeing.