AppearanceThe appearance of the African honeybee is very similar to the European honeybee. However, the African honeybee is slightly smaller. The average body length of a worker is 19 mm. Its upper body is covered in fuzz, and its abdomen is striped with black.
BehaviorThe main difference found between African and European honey bees were a few behavioral traits in the worker bees that were all related to the workers’ food preference. It was found that ''Apis mellifera scutellata'' workers focused on pollen processing behaviors while European workers focused on nectar processing behaviors. African bees were also more likely to store pollen while European bees stored honey. The study found that worker food preferences determined whether the colony maintained a certain reproductive rate. For example, having fewer or relatively older workers who prefer nectar means that the colony will not have the resources available to rapidly or efficiently feed new broods. Worker food preferences have been connected to genotypic variation at specific quantitative trait loci.
African bees are “precocious foragers;” ''A. mellifera scutellata'' bees begin foraging for pollen significantly earlier than their European counterparts ''A. mellifera ligustica'', and this is thought to be related to the fact that African colonies have a younger, skewed age distribution by comparison. However, this is not a direct cause for the different subsistence strategies between the two subspecies.
HabitatThe native habitat of ''Apis mellifera scutellata'' includes the southern and eastern regions of Africa. The species was first imported across the Atlantic Ocean to Brazil before it spread to Central America, South America, and southern areas of the United States. The Africanized honey bee thrives in tropical areas and is not well adapted for cold areas that receive heavy rainfall.
EvolutionThese two strategies have been adopted by the European and African bees respectively. European bees must survive the winter, an annual event with predictable mortality outcomes. Trying to meet the energetic needs of the colony and reproduction might decrease their overall survival during the winter and it is more evolutionarily favorable for them to store nectar and honey. African bees are more vulnerable to less predictable times of scarcity or attack and it is therefore to their advantage to produce as many young as possible, increasing the likelihood that some or even many will survive. Such circumstances would have favored the worker bees who preferred harvesting nectar in European colonies and pollen in African colonies, providing an explanation for how a divergence in worker behavior and age distribution evolved in ''Apis mellifera scutellata'' and ''Apis mellifera ligustica''. Fewell and Bertram’s study is significant in that it provides a plausible method through which the fitness characteristics of the subspecies could have evolved from a small number of behavioral differences in worker bees. The single lineage of parasitizing ''A. mellifera capensis'' may have gained evolutionary advantage because, compared to other related species, it is not susceptible to the host queen’s pheromonal reproductive suppression of workers. The non-invasive varieties of ''A. mellifera c.'' produce less mandibular secretions than the invasive strain. In addition, they produce secretions that are not as similar to that of ''A. mellifera s.'' queens as that of the invasive strain. The single lineage was selected for its greater ''resistance'' to and greater ability to mimic and overwhelm the pheromonal regulation by host queens.The multifaceted aspect of communication in social insects makes social insect colonies easy to hijack. Especially in the case of closely related species and subspecies, the biology and organization of potential host species are similar to that of potential parasitizing species, making them easier to infiltrate. On the other hand, potential parasites face the challenge of being discovered by the host queen, usually the sole reproductive individual in the colony. The existence of ''A. mellifera capensis'' worker parasites is an example of an alternative evolutionary strategy that allows them to increase their “direct fitness in foreign colonies rather than inclusive fitness in their natal nests." Workers usually focus their efforts on raising and caring for larvae that are related to them, thus preserving the propagation of their genes and contributing to their inclusive fitness. The parasitic model is more advantageous by comparison because it allows workers to directly reproduce offspring that are more closely related to them and greater in number, so they are a component of direct fitness.
The invasive lineage of ''A. mellifera c.'' succeeded either because of an inability to recognize the host ''A. mellifera s.'' queen signal correctly or a resistance to the signal. Ultimately this is an interesting example of a preexisting weakness towards social parasitism by ''A. mellifera capensis'' in ''A. mellifera scutellata''. Organisms evolve reproductive strategies that ensure the survival and propagation of the organisms’ genes. Successful reproductive strategies cope with particular economic constraints experienced by the organism. The parasitic relationship between ''A. mellifera scutellata'' and ''A. mellifera capensis'' is an example of how a normally successful strategy of chemical recognition and maintenance of a reproductive division of labor can be undermined by competing, exploitative strategies.The underlying hypothesis for the aggressive behavior of African bees is based on the idea that this race of bees evolved in an arid environment, where the bee's food was scarce. Under this situation, selection favored more aggressive colonies, which protected their food source and hive from predators and robber bees from other colonies. This behavior allowed more aggressive colonies to survive where the less aggressive colonies eventually were selected against by natural selection.
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