SummaryTwenty-four chemical components from the sting apparatus and 2-heptanone from the mandibular glands of the worker honeybee (Apis melliferaL.) were tested at the hive entrance for their effect on alerting, stinging, Nasonov gland exposure, and flight activity. They were further tested at experimental food sources for their effect on foraging activity. In each bioassay, 33–66% of the components appeared to have some effect. Only 2 components, iso-pentyl acetate and 1-pentanol, elicited a response in all tests, and 4 of the less-volatile components elicited no response in any test in which they were presented. Some components elicited different responses when they were presented at different concentrations. Some components had an inhibitory effect on flight and foraging from the hive entrance, whereas others had a stimulatory effect. When presented at food sources, many components were repellent to foragers; a mixture of 2 components, n-octyl acetate and benzyl acetate, had the maximum repellent effect. The roles of these pheromone components in the control of colony activities, and the opportunities for improving honeybee colony management by the use of synthetic pheromones, are discussed.