Africanized Honey Bees

Unlike North America which had no honey bees until the Europeans imported them in 1691, South America had native honey bees. However, the native honey bees were not good honey producers, and the imported European bees failed to thrive in the tropics.  In 1956, tropical African queens (Apis mellifera scutellata) were introduced into Brazil to breed a better bee for the enviroment of South America.  Unfortunately the bees brought over from Africa were, largely, unselected bees, not given to hundreds of years of selective breeding that had been the case with the European bee.  In 1957, some colonies swarmed and escaped resulting in hybridization between the African breed and the European bees. The resulting bees, were referred to as Africanized bees, the name used today.   Africanized bees rapidly took over European bee colonies within three years of their initial Brazilian introduction, and are now the honey bee of choice throughout South America.

Swarms of Africanized bees establish nests in smaller enclosed or partially open cavities, whereas the European breeds use bigger enclosed cavities.  Africanized queens lay more eggs and the young mature three days faster than European bees, resulting in rapid colony growth.   Africanized bees are active year round, maintain a smaller colony, swarm sooner (5 to 7 weeks after their establishment), and swarm year round, producing ten times as many swarms as European bees.  Other than being slightly smaller in size, Africanized bees look identical to their European cousins.  The only sure way to tell them apart is through DNA testing.

In areas with both Africanized and European bees, Africanized drones will drift into European colonies, but European drones rarely will drift into Africanized colonies.   As a result, a virgin queen, be it either Africanized or European, is much more likely to mate with Africanized drones than European drones.

Some problems beekeepers have with Africanized bees are their high swarming and absconding rates, which create a reduction in hive populations and consequently of honey crops. 

Another problem is the difficulty of obtaining apiary sites, due to the bees more aggressive temperment.  While a European bee will chase an intruder up to 30 yards and then settle down, Africanized bees attack en mass and will give chase for 300 yards.  If an extremely defensive  Africanized colony is disturbed, be it by odor, movement, or vibration, 40-60% of the hive (5,000-15,000 bees) will be out in about 15 seconds.  Once disturbed, Africanized bees can remain angry for twenty-four hours, attacking people and animals up to a half a mile from the hive.

Africanized bees are on constant patrol covering about a 100 foot radius around their home.  If you enter this area, the bees will collide with you, but not sting you, as a warning to leave their territory. If you heed the warning and go back the way you came, they will not attack.

Africanized bees have more pheromone receptors than other honey bees, which may contribute to their zealousness in attacks. Their venom is no more potent than European bee venom.  It is the quantity of stings, not the quality of venom, that is the problem.  Five hundred bee stings have as much venom as a rattlesnake bite.  Eight hundred stings will kill an adult.   It takes about 10 stings per pound of body weight to cause a fatality.   Over a thousand have lost their lives due to Africanized bee attacks.  Children, the eldery, and pets are the most susceptible due to their inability to out run the bees.

Since their escape in Brazil in 1957, Africanized bees have increased their area of distribution 200 - 300 miles annually. They reached Costa Rica in 1983, Mexico in 1986, and Texas in late 1990. Since their arrival in the US, southern California, southern Nevada, all of Arizona, much of New Mexico and most of Texas have become occupied by wild populations of the Africanized bee.  Isolated swarms have been discovered in Oklahoma, Arkansas, and Louisiana.  Africanized swarms were positively identified in southern Utah during the winter of 2009, including a swarm that overwintered in the rafters of a home in Cedar City.

An Africanized honey bee swarm was first confirmed in the United States at Hidalgo, Texas in 1990. The first confirmed attack in the United States occurred in 1991 at Brownsville, Texas. The first fatality attributed to Africanized honey bees in the United States occurred in 1993, also in Texas.  By mid-2004, fourteen fatalities had occurred in the U.S. due to Africanized bee stings.

Why are Africanized bees called "killer" bees? It's Hollywood sensationalism and a misnomer. To put this in perspective, there are approximately 350 deaths each year from motorists colliding with deer on the roads. There are also deaths every year from fire ants and venomous snakes.


                                                       

 

The Africanized bee will probably colonize the US the way it has South America, with a southern zone developing where feral honey bees are almost completely Africanized and a northern zone that will continue to be populated almost completely by the European honey bee.  A transition area will probably exist between the northern and southern zones in which the two groups interbreed and their behavior stretching across the entire range of defensiveness.

Africanized bee colonies need to be identified and destroyed, not only for the protection of people and animals, but also to protect the European bee population; as every third mouthful of food we eat is dependant on bee pollination.   Africanized honey bees spend more effort on colony reproduction, while European bees spend more effort on the collection and storage of food.  Since Africanized traits tend to dominate European traits, Africanizition of European hives could have the major  negative effect of reduced pollination of fruit, vegetable, seed, and fiber crops.

What to do if attacked by Africanized bees:

Field research outside of Mexico City is working to identify and breed gentler Africanized bees. Africanized bee hives are tested for honey output.  Hives with high output are then tested for personality.  Those that get angrier quicker are destroyed, removing the most aggressive genes from the larger bee population.   A third test is then performed for flightiness.  The surviving hives have resulted in an Africanized bee that produces 20% more honey and is 50% less defensive.


The African Bee in Africa

With all the bad publicity the Africanized bee has had in the western hemisphere, the African honey bee is the preferred bee of African beekeepers.  In its homeland, the AHB is prized as a good honey producer thriving on erratic food supplies in a semi-desert climate with severe droughts.  African bees tend to be 10% smaller than European bees. Additionally, they are 25% lighter, reproduce earlier, and have a shorter lifespan. 

Another African bee kept by beekeepers is the Cape honey bee. The Cape bee's native territory was only on the Cape Coast on the tip of South Africa.   The bees did not interbreed until the 90s when beekeepers started moving hives between the two territories.  After moving Cape bees into AHB territory, the Cape bee started invading the hives of AHBs.  Within a year, tens of thousands of hives, equaling 50% of the managed AHB hives, had to be destroyed.

A Cape worker bee is not like other honey worker bees. She is capable of laying eggs that produce fully functional queens from unfertilized eggs (thelytoky)! (Cape workers do not exhibit this behavior in a queen right Cape colony).  Cape worker bees invade the hives of AHBs. Most are killed by the hive residents, but a few escape detection and are absorbed into the hive, setting off a chain of events that will eventually cause collapse of the hive. Cape bee laying workers emit queen-like pheromones exerting reproductive control. The Cape worker tricks the resident bees into treating her like a queen, with the African bees eventually killing their own queen.   Colonies taken over by Cape bees will no longer accept AHB queens. The eggs laid by the Cape worker develop into females who beg for food, eating more than their African bee nest mates. With less AHB foragers the food supply is soon depleted, the colony collapses, and the Cape bees leave to find another place to freeload.

Using Cape bees to eradicate the Africanized bee in America is not the solution. They would destroy the European honey bee population just as they are destroying the African honey bee population in Africa.