Responding to your comment about leaving Apistan strips in hives continuously. This practice places a continuous selection pressure on the mite population - only mites that do not respond to Apistan treatment will live to produce the next generation of mites. Treatment followed by a period without treatment, as recommended on the label, allows mites that are not resistant to Apistan to reproduce. In addition, mites from the surrounding area are likely to invade the colony and further dilute the resistant population. If you want more information on why this procedure is the recommended practice look up recent references to "refugia" in entomological journals. Your acquaintance is doing what is easiest for him by leaving Apistan strips in his colonies continuously. He is, however, putting the entire beekeeping community at risk by applying treatments in a manner that will shorten the life expectancy for Apistan being a valuable beekeeping tool. He should treat according to the label and develop a sampling or monitoring program for deciding when another treatment is merited. This is easier said than done for a commercial beekeeper, however, we currently have only one option for controlling varroa in our colonies. We should do all we can to protect that option. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Marion D. Ellis Assistant Professor and * * University of Nebraska Extension Apiculture Specialist * * Department of Entomology email: [log in to unmask] * * P.O. Box 830816 Phone: 402-472-2125 * * Lincoln, NE 68583-0816 Fax: 402-472-4687 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *