The occurrence of honeybee viruses in apiaries in the Koprivnica- Križevci district in Croatia

Viral honey bee diseases are an increasing beekeeping problem throughout the world because they can cause great economic losses and a reduction in biodiversity in natural ecosystems. Therefore, it is important to promptly identify the causal pathogens of honey bee diseases in order to develop appropriate measures and procedures for their prevention and eradication. In this paper the prevalence and distribution were determined of the fi ve economically most important honey bee viruses in the Koprivnica-Križevci district by Reverse-transcriptase PCR (RT-PCR). In addition, the honey bee samples were examined for the presence of the mite Varroa destructor. In the investigated apiaries the following viruses were identifi ed: Deformed wing virus (DWV) with 100%, Sacbrood bee virus (SBV) with 70%, Black queen virus (BQCV) with 20%, Acute bee paralysis virus (ABPV) with 10 % and Chronic bee paralysis virus (CBPV) with 10 % incidence. Multiple infections of the examined honey bee colonies were found in 80 % of samples. Key words: honey bee viruses, reverse-transcriptase PCR, Koprivnica-Križevci district_______________________________________________________________________________________