Hi. Last fall I treated my 140 colonies with extender patties for tracheal mite and AFB control. I am noticing that many colonies now have about half the pattie remaining, but I'm not sure if this terramycin is still active. Should I remove the residue and treat again, or will the residue be effective thru early spring? Does anyone have knowledge or an opinion regarding terramycin stability to help with the above question? Thank you. Jim King, Riegelsville, PA