Africanized honey bees have spread from Brazil, south to northern Argentina and north to South and Central America, Trinidad in the West Indies and Mexico. They were first recorded in the United States (Texas) around 1990. By 1992, the were established in Texas, Arizona, New Mexico, Florida and southern California. From there, the AHB gained Louisiana and Arkansas, and in 2009, the invasive bees were also recorded in Utah.
This bee strain thrives in tropical climates where it competes effectively against European bees (brought to North America centuries ago). At their peak rate of expansion, the Africanized honey bees spread north at a rate of almost two kilometers (more than a mile) a day, preceded by their scary reputation of being "killer bees".
What are Africanized Honey bees?
Africanized honey bees (AHB) are hybrids of the African honey bee, (Apis mellifera scutellata), with various European honey bees such as the Italian bee (A. m. ligustica) and (A. m. iberiensis), that have been brought to North America centuries ago.
Honey bees from Africa (Tanzania) were brought to Brazil in the 1950s to try and create an improved honey producing mix strain with the European bees. However, 26 African bee queens accidentally escaped, in 1957. Their descendants, breeding with domesticated European drones (males) quickly established a large wild population of Africanized bees, unknown to South America before. The new strain proved better adapted to the tropical environment than its European counterpart and over the next five decades, it expanded into most of tropical and subtropical America, and later into a number of southern states in the USA.
Africanized honey bees are virtually impossible to visually recognize. Indeed, if the African honey bee is roughly 10% smaller than the European one, and consequently builds smaller comb cells too, the difference is far less visible still with the Africanized honey bees, which are a mix of the two species. For the experts, they do have slightly shorter wings, but this could have them mistaken for the Egyptian bee, which also occurs in the southeastern United States. To positively identify the Africanized honey bee, a DNA testing is thus required.
Are Africanized honey bees really more aggressive?
Almost impossible to recognize physically, Africanized honey bees are, on the contrary, quickly identified by beekeepers from their behavior.
Africanized honey bees are considered "wild" and, though it is normal for any bee colony to defend its hive, Africanized bees do so with gusto. They are easily angered by animals and people, and likely to become aggressive.
For example, if you disturbed a colony of European honey bees, the bees tend to stay close to the hive to defend it. In the same case, Africanized bees explode from the hive to defend it from the outside by flying all around the intruder, like a cloud, persistently trying to intimidate it.
Tests have shown that bee agitation would typically measure a 1 or 2 on a scale of 10 for European bees, but 9 or 10 for Africanized bees, with a range of stings on a felt flag between 0 and 10 for the former, and between 400 and 500 on the latter.
Africanized bees hyper-defensive behavior also involves having a larger alarm zone around their hive (the AHB responds quickly to disturbances by people and animals 50 feet or more from the nest, and can sense vibrations from power equipment more than 100 feet away), a higher proportion of "guard" bees within the hive, deploy in greater numbers for defense, and pursue potential threats over much longer distances (more than a mile as opposed to fifty yards for European bees) from the hive.
The Africanized honey bees' defensive behavior is thought to have evolved because of the many threats their ancestors had to face in their native Africa (such as aggressive insects, honey badgers, and humans who, traditionally, robbed them of their honey by destroying their hives instead of practicing beekeeping).
By opposition, the European honey bees in the U.S. has been selected by beekeepers over hundred's of years for manageable traits: reduced swarming, high honey production and...gentleness.
However, it has been noted that at higher elevations in South and Central America, the AHB is less defensive and not as dominating as you move from tropical and subtropical to temperate climatic regions. Besides, as the bees move further north and further cross breeding takes place with the European honey bees, the characters of the Africanized bees are also likely to change and, hopefully, become milder.
Do AHB deserve to be called "killer bees"?
The Africanized bee is widely feared by the public, a reaction that has been amplified by sensationalist movies and some of the media reports.
It is true that the AHB can kill (like any other bee, actually) and can present a danger even to those not allergic to bee venom. There has, indeed, been isolated cases of animals, and people, stung to death.
A total of 11 people have been killed by Africanized honey bees between their first appearance in the United States, in 1990, and 2002; another 6 until mid-2008. It's, of course, always 17 too many, but, in reality, it amounts to "only" a person a year; it that enough to be labeled "killer bees"? Besides, though the area affected by AHB is steadily increasing, the number of fatal accidents involving humans is remaining stable.
So far, Africanized bees have been responsible for a very small portion of deaths from stinging insects each year. Indeed, some 30 persons a year die in the United States from stings received from other bees, wasps and ants. In Texas, one of the first states to be invaded, AHB have been responsible for roughly .085 percent of the stinging deaths between 1990 and 2002.
It is true, though, that hundreds of non-fatal accidents have also been reported, and that the above figures should be judged comparatively to the number of AHB present compared to European ones, which, in practice, is difficult to do.
What makes Africanized bees more dangerous (besides the fact that they are more aggressive) has nothing to do with the venom itself (it is the same as with European bees), but with the quantity involved. Being slightly smaller than their European counterparts, the AHB, tend to inject slightly less venom, however, a person is more likely to receive multiple stings from the Africanized bees, and consequently to die (or be severely affected) from too much poison. Allergic people are at risk too, of course, but not really more than with domesticated bees.
Many bee experts think that the term"killer bee" is exaggerated and largely due to the media playing on the people's fears. If one person dies from a bee sting, especially from an AHB sting, it is sure to make the headlines, with such alarming titles as "they are out to get us". While the AHB are just defending their hives, nothing more.
In reality, Africanized honey bees are more likely to be disruptive to beekeepers, and to a lesser degree to agriculture, then to be a health hazard to the average American.
Besides, most human incidents with Africanized bees have occurred within two or three years of the bees' arrival and then subside.
Is the coming of the AHB all bad news?
When the AHB arrives in an area, the backyard beekeeper, and some professional beekeepers, more often then not, stop keeping bees.
In some areas, like California, the cold-weather limits of the Africanized honey bee have driven some southern California beekeepers into zones of harsher winter climate, like the northern Sierra Nevada or the southern Cascade range. Those areas, however, are not as efficient in preparing bees for early pollination placement - notably for the almond industry. Because food for the bees is not abundant enough during northern California's winter, the bees must be fed for early spring build-up.
Beekeepers that stay in business in affected areas often battle to find locations for their hives, because of the bees' reputation of extreme aggressiveness. They also suffer from the competition over nectar resources with the wild AHB.
In Central America, the AHB threatens the old tradition of keeping stingless bees in log gums, even though they do not interbreed nor directly compete with the latter. Indeed, the Africanized honey bees produce so much more honey that it pushes beekeepers to prefer and adopt them.
When the AHB settles in an area, many commercial beekeepers simply adapt to the new situation, and go on with their business. Whereas for new beekeepers, who have never known anything else, they don't seem to really be affected by the Africanized bee. They are just extra careful. After all, beekeepers keep the African honey bee (A. m. scutellata) in South Africa using common beekeeping practices without excessive problems.
The swarming Africanized bees have also provided many poor farmers in South and Central America with an unexpected free source of income, once they captured them.
Whereas for the aggressivity of the AHB, it can be reduced if American beekeepers -like their Brazilian colleagues- start selecting Africanized bees, by culling the queens of the most aggressive strains and replacing them with gentler ones they breed (from the most gentle AHB colonies) or with the queens of European bees.
However, frequent requeening, adds to the loss of locations for hives and resource competition, and is likely to drive the cost of beekeeping operations up. Will an industry already hard hit by other problems (notably the American Foul Broad and the colony collapse disorder) still be profitable, under such conditions?
The danger or overreacting
As the AHB spreads further in North America, and notably in densely populated areas such as the state of Florida, it can be feared that the public will push for misguided efforts to combat them. For instance, people might try to get hives banned in urban and suburban areas. Which would, not only be bad for the beekeeping business, but also for the defense against the Africanized bees. Indeed, they are much more likely to spread quickly and settle in a area where they don't have to compete with other bees. The presence of European bees also means more cross breeding between the two strains, and in the end, less aggressive AHB.
An excessive panic reaction would probably be detrimental to the tourism industry, notably.
Besides, banning beekeeping from certain areas could have disastrous effects on agriculture: honey bees (whether Africanized or not), which are the main pollinating agents of many plants are vital to our economy and food supply.
In this light - and before people everywhere take it into their hands to declare a war on bees - it appears vital to inform and educate the public, concerning the value of bees to agriculture. Instead of letting sensationalized press releases educate them in their own way.
Albert Einstein once stated that if all bees were to disappear from the surface of the Earth, the human race would have four years to live. Maybe we should meditate those words of wisdom...
All about "killer bees"
June 26, 2002--Dewey Caron, professor of apiculture in the University of Delaware College of Agriculture and Natural Resources, is a renowned bee expert who has recently published the book, "Africanized Honey Bees in the Americas."
African Honey Bee: What You Need to Know
First ''killer bees'' death in Florida suspected, 2008