Authors
Krystyna Pohorecka
krystyna.pohorecka@piwet.pulawy.pl
National Veterinary Research Institute, Department of Honey Bee Diseases, Puławy, Poland
Piotr Skubida
Research Institute of Horticulture, Apiculture Division, Puławy, Poland
Piotr Semkiw
Research Institute of Horticulture, Apiculture Division, Puławy, Poland