Das Projekt "Occurrence and distribution of insecticide resistance in stable flies (Stomoxys calcitrans) on dairy farms in the federal state of Brandenburg, Germany" wird vom Umweltbundesamt gefördert und von Universität Berlin, Institut für Parasitologie und Tropenveterinärmedizin durchgeführt. Stable flies (Stomoxyinae) frequently constitute a common problem in and around livestock farms or in agriculture. Nuisance by biting flies and the ensuing negative impact on livestock productivity plays an important role. Disease transmission may sometimes be an additional problem. The frequent and uncontrolled application of insecticides is likely to speed up the development of insecticide resistance within a few generations as was also shown in a previous investigation on the resistance status of Musca domestica in Brandenburg. Surprisingly, little is known about the resistance in S. calcitrans in Germany. But, there are clear indications from own, unpublished investigations that stable flies have already acquired resistance against pyrethroids. Estimates of the economics of stable fly-induced losses point to as much as Dollar 2billions/year for the cattle sector in the US. It is unfortunate that we do not dispose of reliable estimates of the economic impact of stable flies in Germany. Trials protecting dairy cows against attacks from nuisance insects point, however, to significant reductions of defensive movements and a resulting significant increase of milk production. In this survey it is planned to assess the present status of occurrence and distribution of insecticide resistance in S. calcitrans on dairy farms in Brandenburg, Germany. The goal of this work is to develop a rational approach in pest management, assisting farmers in applying best-bet and environmentally sound strategies for the control of nuisance flies on dairy farms.