Influence of queen presence or absence and worker behavior on honey bee worker longevity

Aging is a universal process that occurs in all organisms. While a negative correlation between reproduction and lifespan is commonly observed among a variety of species, the inverse is found to be true in social insects. Individuals in social insect populations that specialize in reproduction exhibit significantly longer lifespans than their non-reproductive counterparts. This is particularly true for the honey bees (Apis mellifera), in which the queen can outlive a summer worker by up to several years. Previous research has attempted to identify the causes of this differential in life expectancy by directly comparing queens and workers, but the results of such an approach are confounded by the many differences unrelated to aging that exist between queens and workers. In this study, we expand these efforts and concentrate on the influence of reproductive activity on the longevity of honey bee workers. We hypothesize that there is a connection between reproductive social structure, behavior, and mortality. Nine observational hives were set up: three control hives containing a queen and six treatment hives without queens, three including brood. Equal sized cohorts of newly-emerged workers were marked with distinctive numbered tags and introduced to the hives. Worker mortality and different social behaviors were compared between treatment to investigate the life history of reproductive workers, as an intermediate between non-reproductive workers and queens. Our results contribute to the understanding of aging plasticity in the honey bee and how social structure, behavior, and aging are linked through social roles in the colony.