Characteristics of north-eastern population of Varroa destructor resistant to synthetic pyrethroids

The aim of the study was to discover whether strains of Varroa destructor resistant to synthetic pyrethroids can be found in north-eastern Poland and whether cross-resistance occurs in the north-eastern population of mites. The research was carried out from July 2009 to August 2011. Varroa mites from 79 apiaries from north-eastern Poland were examined. Varroa mites resistant to fluvalinate and flumethrin were found in one apiary situated near Olsztyn. These parasites showed an unusual ability to survive as compared to parasites from the other apiaries. In this apiary LC95 for fluvalinate was 5000 ppm, and for flumethrin, 100 ppm. Mites with a high risk of developing resistance to fluvalinate and flumethrin were discovered in two apiaries situated near Kwidzyn (about 100 km south of Gdansk).