David, I 've been using Apistan for about five years. Always applied it for about six weeks during the months august, september or october. I have never noticed that a queen stopped laying during the Apistan treatment. hugo ++++ Hugo Thone / ALCATEL BELL TELEPHONE / SE121 / F.Wellesplein 1 / B-2018 Antwerp Email : [log in to unmask] / Phone : (32) 3 240 94 52 / Fax:(32) 3 240 99 50 do bee do bee do ....