Changes in a population of Apis mellifera L. selected for hygienic behaviour and its relation to brood disease tolerance

Honeybee colonies were evaluated for hygienic behaviour using a pin-killed brood assay. Presence and absence of visual symptoms of brood diseases were recorded. Colonies that removed more than 80% of dead brood after 24 hours were selected for queen and drone production and new colonies were evaluated for hygienic behaviour. This procedure was repeated yearly from 1992 through 1997. The degree of total hygienic behaviour (brood removed) and partial hygienic behaviour (brood uncapped but not totally removed) were determined. Colonies were classified as hygienic and non-hygienic and these data were related to the incidence of brood diseases. Total hygienic behaviour increased in the population after four years of selection on queens without mating control from 66.25% in 1992 to 84.56% in 1997. Hygienic colonies had a lower frequency of brood dis- eases when compared to non-hygienic colonies. It is suggested that this trait can be used as a selec- tion criterion in queen breeders' apiaries. hygienic behaviour / Apis mellifera / selection / brood disease / tolerance