Beekeepers were asked by different Austrian print-media to submit bee samples, in case they observe severe weakening of bee colonies, colony losses, or bees with unusual behaviour. The beekeepers were asked to tell us the location of their apiary (altitude), varroa control measures carried out, degree of varroa mite infestation, and other observations of colony development and unusual behaviour of the bees.

18 beekeepers and the institute for Apiculture sent samples for this study, so there were samples from 23 apiaries from all Austrian federal states. The beekeepers were asked to send bee samples from two of their colonies four times in 2005 according a time schedule (5th-15 th May, 21 st -31 st July, 1 st -11 th September and November-December). Also information about the surrounding of the apiary (altitude, agronomic structure, honeyflow etc.) and about their measures and success of varroa reduction and observations on degree of varroa infestation and colony-health in general was given. Bee samples (ca. 30 bees) were collected in the bottom board of the hive near the entrance to obtain old bees, they were killed by freezing. We also received varroa screens, which have been left about one week in the hives. The varroa mites on the screens were counted.