Africanized bee
Africanized bees are hybrids of the African honeybee, Apis mellifera scutellata, with European honeybees. They are descended from 26 queen bees accidentally released in 1957 in Southern Brazil by biologist Warwick E. Kerr, who had interbred European honeybees and bees from southern Africa. Kerr was attempting to breed a strain of bees that would be better adapted to tropical conditions (ie. more productive) than the European bee used in North America and southern South America.Africanized bees are characterized by their aggressiveness in establishing new hives and in their vigorous defensive behavior, attacking perceived hunters, including people. Over the decades, hundreds of deaths in the Americas have been attributed to them, many resulting from multiple bee stings. This defensiveness has earned them the nickname "killer bees", the aptness of which is debated. European honeybees also kill people due to allergic reactions, and it is difficult to estimate how many more people may have died than would have in the absence of Africanized bees.
As of 2002 they had spread from Brazil south to northern Argentina and north to South and Central America, MÃÂéxico, Texas, Arizona, New Mexico, and southern California. They are spreading north at a rate of almost two kilometers a day.
Recent evidence suggests that Africanized honeybees are less able to survive a cold winter. As this subspecies of honeybee migrates further north, colonies are interbreeding with European honeybees. This appears to be resulting in a dilution of the genetic contribution of the African stock and a gradual reduction of the aggressive behaviors. Thus Africanized bees are expected to remain mostly in the Southern States.
The popular term 'Africanized bee' has only limited scientific meaning today because there is no generally accepted fraction of genetic contribution used to establish a cut-off.
The chief difference between the European races or subspecies of bees kept by American beekeepers and the Africanized stock is attributable to selective breeding. The most common race used in North America today is the Italian bee, Apis mellifera ligustica, which has been kept for several thousand years. Naturally beekeepers tended to eliminate the fierce strains as they did, and the entire race of bees thus gentled by selective breeding.
In central and south Africa, there was no tradition of beekeeping, only bee robbing. When one wanted honey, one would seek out a bee tree and kill it, or at least steal its honey. The colony most likely to survive the human foray was the fiercest one. In addition bees had to defend themselves against honey badgers, an animal that also will destroy hives if the bees are not sufficiently defensive. Thus the Africanized bee has been selectively bred for fierceness.
Not all Africanized hives are defensive; some are quite gentle, which gives a beginning point for beekeepers to breed a gentler stock. This has been done in Brazil, where bee incidents are much less common than during the first wave of the Africanized bees' colonization. Now that the Africanized bee has been gentled, it is considered the bee of choice for beekeeping in Brazil. It is better adapted to the tropics and so is healthier and more industrious than European bees.
If bees start head-butting you, use this behavior as a warning to retrace your steps and walk away from the hive. Choosing any other path could lead you deeper into the hive's territory.
How to Avoid Bees
Use caution with power mowers
Bees are sensitive to low frequency vibrations and so an engine driven lawn mower may elicit a defense response from a hive or swarm.Walk with care in Clover and near Picnic Sites
Take care not to walk barefoot on lawns containing blooming clover, which attracts foraging bees. Meat eating wasps can be attracted to food scraps near a picnic site and usually forage close to the ground.Avoid Perfume, Cologne and Scented Cosmetics
Foraging bees will seek out floral scents. Such a bee will be harmless to you unless you swat at it, as it is only trying to find a flower. Yellowjackets can be much more aggressive, even to the point of biting.Beware of Head-butting Bees
Honeybees usually have a small number of sentry bees patrolling the perimeter of the hive's territory. In some if not most cases, these sentry bees will initially head-butt (not sting) any animal that enters the hive's territory. If the animal continues closer to the hive, stinging will ensue. Wear Light Colors
Honeybees react to dark colors. Knowing this, beekeepers alway wear white (or light colored) protective suits when working with bees during daylight. Bees have poor night vision and so beekeepers wear dark colors when collecting swarms after sunset. When traveling through areas with bees, wear light colors to avoid attracting bees. Bees are inactive at night and are unlikely to be encountered unless you bump into a resting swarm.