Summary. The paper presents and analyzes the main pathogen of the honey bee, Apis mellifera L., their role in pathogenesis of diseases and mechanisms of an insect response to infections. Peaniba-cillus larvae larvae, a causative agent of American foulbrood and Varroa destructor, a hemato-phagous ectoparasitic mite, are now the greatest threat for beekeeping all over the world. The honey bee defends itself against parasites and pest by different protective mechanism: behavioral, anatomical and physiological barriers, cell-free and haemocytic defence reactions. Most of them, operating in harmony, can effectively prevent infections. The best know are behavioral responses, native and inducible polypeptides and proteins of antibacterial active. Due to antibacterial de-fences, the colony may survive in the environment full of entomopathogenic viruses, bacteria, fungi and parasites.

Key words: P. larvae, Varroa destructor, native and inducible immunity