[log in to unmask] +++++ Eric Abell wrote: >It has been my understanding that the acid >will not kill the mites beneath the capping. If you have a way to treat the >brood with Formic acid would you please elaborate. ----------------------- While awaiting news of the method the author had in mind, I thought that I would add that last November there was a presentation at the OBA (Ontario Beekeepers Association) convention about mite control with Formic acid, From what I remember it did indeed kill the mites under the cappings since the fumes travelled through the wax cappings much as water vapour does. In a nutshell: Place a 8" X 9.5" piece of .5" thick tentest (Homosote) in a 12" X 12.4" Ziploc vegetable bag and soak in 250ml of 65% Formic acid until all was absorbed, Place on top of brood frames on .5" thick spacers. Place a 1" rim around the brood chamber to accommodate this and cover hive. Leave for 15 to 21 days. During treatment the temperature should be between 12 and 25 degrees Centigrade with night temperatures not below 7 degrees C. All materials and technique are critical in order to obtain the wanted evaporation rate of 10 ml./day which kills the mites and has no significant effect on brood. Treatment must stop before honey supers are put on. BTW Formic acid treatment is legal in Canada, This vapour treatment is recommended to use in spring along with Apistan (a contact chemical spread by the bees as they crawl over the strips). These two different chemicals and method of transport help to avoid breeding resistant mites. BTW2 I understand that Formic acid is effective for controlling BOTH Varroa and Tracheal mites. BTW3 Drone trapping is being used by some here when mite build-up is observed but during honey flow in on and thus no chemical treatment can be used. george fielder