Bee Removal & Extermination
There are currently 28 recognized subspecies of Apis mellifera based largely on geographic variations. All subspecies are cross fertile. Geographic isolation led to numerous local adaptations. These adaptations include brood cycles synchronized with the bloom period of local flora, forming a winter cluster in colder climates, migratory swarming in Africa, enhanced foraging behavior in desert areas, and numerous other inherited traits.
The first Africanized bees in the US were discovered in 1985 in the San Joaquin Valley of California hatched onto a Venezuelan oil tanker. By 1990 they spread to Texas from Mexico. In the Tucson region of Arizona, the study of trapped swarms in 1994 found that only 15 percent had been Africanized; this number had grown to 90 percent by 1997.
The Africanized honey bees in the Western Hemisphere are of mixed descent from 26 Tanganyikan queen bees of A. m. scutellata, accidentally released by a replacement bee-keeper in 1957 near Rio Claro, São Paulo, in the southeast of Brazil, from hives operated by biologist Warwick E. Kerr, who had interbred honey bees from Europe and southern Africa. Hives containing these particular queens were noted to be especially defensive. Kerr was attempting to breed a strain of bees that would produce more honey and be better adapted to tropical conditions (i.e., more productive) than the European subspecies of honey bee used in South America and southern North America. The hives the bees were released from had special excluder grates to prevent the larger queen bees and drones from getting out and mating with local queens and drones of European descent. However, following the accidental release, the African queens and drones mated with domesticated local non-African queens and drones, and their descendants have since spread throughout the Americas.
The Africanized bees have become the dominant type of honey bee for beekeeping in Central America and in tropical areas of South America due to them outcompeting the European subspecies, and there are claims that they have improved productivity. Unfortunately, the extreme tendency of Africanized bees to swarm has had a significant impact of honey production in managed colonies and in most areas the Africanized bees tend to have certain behavioral traits that make them less desirable for managed beekeeping. Specifically, as compared with the European bee types, the Africanized bee:
- Tends to swarm more frequently and go farther than other types of honey bees.
- Is more likely to migrate as part of a seasonal response to lowered food supply.
- Is more likely to "abscond"—the entire colony leaves the hive and relocates—in response to stress.
- Has greater defensiveness when in a resting swarm, compared to other honey bee types.
- Lives more often in ground cavities than the European types.
- Guards the hive aggressively, with a larger alarm zone around the hive.
- Has a higher proportion of "guard" bees within the hive.
- Deploys in greater numbers for defense and pursues perceived threats over much longer distances from the hive.
- Cannot survive extended periods of forage deprivation, preventing introduction into areas with harsh winters or extremely dry late summers.