THE EFFECTS OF COLONY LEVEL SELECTION ON THE SOCIAL-ORGANIZATION OF HONEY-BEE (APIS-MELLIFERA L) COLONIES - COLONY LEVEL COMPONENTS OF POLLEN HOARDING

Two-way selection for quantities of stored pollen resulted in the prod uction of high and low pollen hoarding strains of honey bees (Apis mel lifera L.). Strains differed in areas of stored pollen after a single generation of selection and, by the third generation, the high strain colonies stored an average 6 times more pollen than low strain colonie s. Colony-level organizational components that potentially affect poll en stores were identified that varied genetically within and between t hese strains. Changes occurred in several of these components, in addi tion to changes in the selected trait. High strain colonies had a sign ificantly higher proportion of foragers returning with loads of pollen , however, high and low strain colonies had equal total numbers of for agers. Colony rates of intake of pollen and nectar were not independen t. Selection resulted in an increase in the number of pollen collector s and a decrease in the number of nectar collectors in high strain col onies, while the reciprocal relationship occurred in the low strain. H igh and low strain colonies also demonstrated different diurnal foragi ng patterns as measured by the changing proportions of returning polle n foragers. High strain colonies of generation 3 contained significant ly less brood than did low strain colonies, a consequence of a constra int on colony growth resulting from a fixed nest volume and large quan tities of stored pollen. These components represent selectable colony- level traits on which natural selection can act and shape the social o rganization of honey bee colonies.