Scott Bauer / USDA-ARS
An Africanized honeybee, left, and a European honeybee sit side by side on honeycomb. Despite the color differences between these two bees, normally they can't be identified by eye.
By Jennifer Viegas
Larry Goodwin, a 62-year-old farmer in Moody, Texas, met a painful death last Monday when he accidentally disturbed a hidden hive of Africanized honebees, a.k.a. "killer bees," as he drove his tractor on a neighbor's land.
NBC News report: Killer bees leave Texas man dead
The bees swarmed from their hive in overwhelming numbers, prompting Goodwin to run to a nearby house and grab a garden hose to try and spray away the fierce insects. But the hive with an estimated 40,000 bees, overtook the farmer and killed him with their stings.
Goodwin's was a horrific and unusual death -- but how exactly do these bees kill?
"These are extremely defensive and dominant bees," said Eric Mussen, extension apiculturist at the UC Davis Department of Entomology and Nematology.
"Africanized honeybees are extremely sensitive to vibrations," Mussen explained. "If a lawnmower goes off several houses away from a colony, for example, the bees could still likely detect the vibrations and sting everyone in the area."
When disturbed, the killer bees have extra soldiers on duty to respond to alarms. The bees are slightly smaller than honeybees and have the same venom load per sting, but a defensive attack, such as the one that killed Goodwin, can be devastating.
Mussen explained that if a European bee colony is disturbed, the victim may be stung 12 to 20 times, or up to 200 times if the entire colony is somehow tipped over or otherwise dramatically bothered.
If a killer bee colony senses a threat, on the other hand, the victim could be stung around 2,000 times.
Yet another threat comes from the double-damaging venom. Meletin, the primary pain-inducing compound in the venom, makes up about 50 percent of the mixture. Another component, called "phospholipase A2," gives the venom the ability to damage human tissue. The damage can be so severe that the material can overload the kidneys, resulting in kidney failure days after the individual was stung.
Some doctors overlook the latter problem and release patients before the kidney threat is treated, according to Mussen. In one case, Mussen had to advise a victim's wife to have her dying husband go through dialysis, which eventually saved his life.
Africanized honeybees resulted from a bee breeding experiment that went horribly wrong. Now their numbers continue to expand across the United States.
According to Mussen and an information sheet provided by the University of Arizona College of Agriculture and Life Sciences, the bees are connected to research conducted by Brazilian geneticist Warwick Kerr. The Brazilian Agriculture Ministry had Kerr bring African honeybee queens to Brazil for breeding experiments.
Steve Haydon, curator and collections manager at the Bohart Museum of Entomology, told Discovery News that one goal of the experiments was to create a hybrid bee that would possess the hearty characteristics of African bees, but the more docile behavior of European honeybees.
"Some of the queens got away," Haydon said.
Left out of control, the African bees bred with honeybees in the wild. The results were anything but docile.
Since Africanized bees are a hybrid, "there is no way to selectively reduce their population," he said.
Both he and Heydon advise that the public practice “outdoor awareness,” taking care not to bump into a hive or otherwise disturb bees.
Mussen added that if you are attacked, running away, if possible, is a wise course of action.
Even this isn't possible if the bees sting your nose, which can cause eyes to tear or water. This has happened to some victims, who wind up falling over and are then stung all the more. Stings give off a banana scent that attracts other bees and further promotes their defensive behavior.
He advises hikers and others who might be at higher risk to carry a small amount of netting that could be used to cover the head should an attack occur.
In the United States, killer bees have expanded their territories by about 60 miles per year. They are currently known to be in Texas, Arizona, Nevada, New Mexico, Florida, southern California, southern Louisiana, southwest Arkansas, southern Georgia and eastern Tennessee.