INTRA-COLONY DEMOGRAPHY AND REPRODUCTIVE RATE OF THE AFRICANIZED HONEYBEE IN SOUTH-AMERICA

1. Demography and growth patterns of Africanized honeybee colonies in South America are described, and the influence of worker survivorship, rate of worker production, age structure, and colony growth patterns on their reproductive rate (swarm production) is discussed. 2. During a reproductive cycle, a colony passes through four phases: pre-emergence, post-emergence, pre-swarming, and post-swarming. Growth in the worker population approximates a sigmoid curve, but swarming occurs before high growth rates peak. Colonies swarm at a small size, with sufficient workers to produce viable prime swarms and afterswarms, as well as to continue the parent colony. 3. The timing of adult worker emergence influences the number of afterswarms, as well as the number of adults maintained in the original colony when swarming is completed. 4. Patterns of survivorship for both brood and adult workers shift during swarming cycles, with high brood mortality and reduced adult longevity early in the cycle, in contrast with lower brood mortality and increased longevity of adults as colonies mature. 5. Survivorship appears to be related to the age structure of colonies, with high mortality at points in the swarming cycle at which there is a high mean worker age and a low proportion of young workers. The age structure of colonies also shifts during swarming cycles with a progressive increase in the proportion of young workers. A consequence of this shift is that swarms are populated predominantly by young workers. Patterns of survivorship and age structure influence colony growth rates, and thus partly determine the rate of swarm production. © 1979 Springer-Verlag.