Africanized and European newly emerged workers were reared at the same time for 14 days in the same cages treated with 1) brood pheromone, or 2) blank control. On day 14, 30 bees per genotype were dissected per treatment and their ovary development scored. In 6 paired replications, the Africanized genotype invariably showed significantly greater ovary development compared to European workers in the brood pheromone and control treatments. Ovary development was significantly reduced in brood pheromone treated versus control treated bees in both genotypes. The lower response threshold for colony-level reproduction appears to carry-over to individual-level response threshold to reproductive stimuli in the Africanized honey bee compared to the European honey bee.