Dale Marmaduke queried: > What are the techniques currently being used with Formic Acid (FA). Currently FA is not registered for use in beehives within the United States. Beekeepers from Canada are more likely to be able to offer first hand experience. I have heard differing accounts on the use of FA ranging from squirting it into a hive from a garden sprayer to placing absorbent boards soaked in FA into hives. There are also devices which hold reservoirs of FA and disperse it into the hive via wicks (such as the Nassenheider Evaporator and Popodi device, among others). Some problems with the application methods above are obvious; unknown doses being delivered, uncontrolled evaporation rates of unknown quantities, and varying FA concentrations. Also bear in mind that FA is very caustic, nasty stuff. Rubber gloves and aprons, respirators and eye goggles are always recommended when using FA. This is why so much effort has been expended by the USDA in developing a gel formulation of FA. Attempts have been made to make the gel formulation more user friendly, more controlled in its release within the hive environment and generally less dangerous and more controlled. I was surprised to read Andy's post which called gel FA a hobby beekeeper solution. One of the goals of the gel formulation was to come up with a product that would be financially sound for commercial operations also. Current application practices require repeated trips to apply more FA to a hive whereas the gel formulation may only require a single application. The gel developers kept commercial beekeepers in mind during the development process. Furthermore, FA is not without its drawbacks. Queen supersedure was/is a common problem with uncontrolled release of unknown quantities and concentrations of FA. This is another problem that a more controlled release via a gel formulation may address. Finally a disclaimer. I have never used FA. I am not to be considered an authority on its use or effectiveness. I have followed the developments in its use (much of which has been trial and error by pioneering beekeepers) and I have watched the trials and tribulations of Dr. Shimanuki as he has tried to bring gel FA to the marketplace. I have no vested interest in FA other than it may be a tool for me to use to combat both Varroa and Tracheal mites and I will most likely use it once it is legal to do so. There is a plethora of information regarding FA in the BEE-L archives. Send a single line of mail to: [log in to unmask] that reads: SEARCH BEE-L "formic acid" Aaron Morris - I think, therefore I bee!