Larry asks about alternatives. First, Larry, in your climate I question whether any 'airing out' in the spring in necessary. When I used it (I no longer do, but that story is later) I made one application a stack, following directions. That was in September or October, depending where the supers were in the extraction process. The first time I put them on a hive was the following May, at least 5 months later. I found that amount of time was more than enough to preclude any bee/larvae damage. (I am near Albany, NY and Larry is near Chicago.) Around here we have lots of commercial beekeepers and none use PDB or anything similar. Instead, they let the bees rob the combs after extraction. While the wax moths are after the spent cocoons and not the honey, something about the robbing eliminates the wax moth larvae and makes the combs unattractive to infestation. (Perhaps someone can tell us why this is so.) Our first frost is typically about October 15, but beginning about Sept 15 we have many nights in the high 30's, and those temperatures slow down the wax moth so the pressure of infestation is relieved. In this climate, the rule of thumb is that no significant wax moth damage will result until after July 1, and in some fields nearby there are still huge stacks of supers waiting to be put on hives. Lloyd Lloyd Spear, Owner Ross Rounds, Inc. Manufacturers of Ross Rounds Comb Honey Equipment, Sundance Pollen Traps and Custom Printer of Sundance Labels. :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: -- Visit www.honeybeeworld.com/BEE-L for rules, FAQ and other info --- ::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::