Rod wonders if he should treat again for mites, as he had a 20 mite fall (with no Apistan) in 48 hours. This also sounds to me as if it is a large drop. Unfortunately, no one knows the significance of any counted drop. Moreover, the importance of a 20 mite drop in upstate NY (where I am) might not be at all important in Missouri! Have you tried your extension service for guidance? Perhaps they could put you in touch with someone at Missouri's ag school. You are now at the mid-point between treatments. However many mites are in your hives, they will roughly double in number every 30 days. Obviously, things could get critical very fast. Can you count on reasonably good temperatures for the next 28-40 days? If you can, I would treat now. Don't worry about over-using Apistan, as it is now a certainty that the formic acid gel pack will be available in the spring and that should be rotated into your schedule. Your bee supply dealer will have it. Hope this helps. Lloyd Lloyd Spear, Owner, Ross Rounds, Inc. The finest in comb honey production. www.rossrounds.com