Improvement in the health of the brood in colonies of bees (Apis mellifera L.) selected for hygienic behaviour

Abstract

Brood infectious diseases, specially American foulbrood, caused by the bacterium Paenibacillus larvae, and the parasitic mite Varroa destructor, are responsible for great economical loses in beekeping industry. Control of sanity of colonies using antibiotics and acaricides, have given rise to numerous cases of pathogen resistance. With the aim of increasing bee resistance to brood diseases and varroa, we performed a mass selection of colonies, to improve bee hygienic behaviour (cells uncapping and ulterior removing of diseased or parasited larvae). After six generations, colony hygienic behaviour increased from 77.7 ± 20.9% to 98.7 ± 1.7%, and proportion of colonies with brood diseases reduced from 50% to O. Diseased colonies presented significantly less hygienic behaviour than the healthy ones. Regarding varroa infestation, our results indicate that hygienic behaviour is not an efficient resistance mechanism to control mites. Honey bees genetic improvement is an important tool to reduce the negative impact of brood diseases in the short term.