If you live in the South or Southwest, you have certainly heard, or read, about the northward progression of African honeybees, more sensationally known as "killer bees."
"Elderly Woman Attacked By Killer Bees," The Arizona Daily Star, 10/95;
"How To Deal With Killer Bee Attacks," Green Valley News and Sun, Arizona, 7/9/95;
"Bees Kill Two Horses, Injure Third," Tucson Citizen, 7/13/95;
"Toxin From African Bee Sting Took Days to Kill Woman," Orange County Register, California, 10/12/95;
"Agriculture Officials Say Killer Bees Near," Orange County Register, 11/95;
"Tree Trimmers Attacked by Killer Bees," Orange County Register, 12/30/95;
"Golfers' Stings Show Higher Killer Bee Activity," The Arizona Daily Star, 1/19/96.
Some of these headlines may seem a bit melodramatic, but bee attacks can be deadly to humans and animals, particularly horses. It just took the aggressive demeanor of the African honeybee to bring it to everyday consciousness.
"Bees and horses just don't mix," claims Steve Thoenes, PhD, a Tucson-based entomologist who specializes in the swarming habits of bees. "When bees get angry, horses are very attractive and vulnerable targets. Horses should never be stabled or corralled near honeybee colonies."
A recent attack by African honeybees in Phoenix, Ariz., left two horses dead and another horse and two farriers nursing a plethora of bee stings. Another attack, outside of Tucson, resulted in a rider being thrown from his horse and knocked unconscious.
"We have had several horses killed in Arizona," said Thoenes. "Due to their size, horses rarely die from bee toxin. They usually suffocate first."
Thoenes doesn't know why, but somehow honeybees know that the eyes and nose are vulnerable areas. The bees locate these areas by seeking out carbon dioxide released through the nose and mouth.
"When a horse is subjected to multiple bee stings around, and in, the nose, the area swells and cuts off a horse's breathing," he said.
Despite the sanguinary image portrayed in the Hollywood film, The Swarm, and the made-for-television movie, The Savage Bees, bees do not seek out victims to sting to death. They will, however, attack in defense of their colony. Between 1988 and 1993, African honeybees have been responsible for at least 192 deaths in Mexico, or one death per year per 1.4 million people. Almost three-quarters of the deaths were adults over 50. To date, four U.S. citizens, two in Texas and two in Arizona, have been killed by African honeybees.
Although the African honeybee has sullied the image of honeybees, honeybees are still a necessary component in the pollination of innumerable flowers, fruits, and vegetables. Crops requiring bees for pollination include almond, avocado, plum, prune, cherry, and apple trees; melons and other squash; alfalfa, and kiwi fruit. Without adequate pollination, yields are reduced and the vegetables and fruit might be small or misshapen.
So, how do you tell the difference between the common garden honeybee and the African honeybee? You don't--that is until you are under attack! It is the African bee's behavior that distinguishes it from its cousin, the European honeybee. Compared to the African bee, the European honeybee is much more placid and tolerant of intruders. Whereas the European honeybee will pursue victims short distances, the African bee will chase perceived intruders for up to a quarter of a mile. In addition to its excessively defensive behavior, African bees swarm more frequently than other honeybees. European bees swarm, or move, only about once a year, while African bees might swarm as many as 10 times a year.
"All tropical species of bees are mean because they have so many predators," Thoenes said. "Because of constant attacks on their hives, the African honeybee has evolved into a very defensive bee that swarms constantly in order to stay ahead of predators (bears, skunks, honey badgers, ants, and humans)."
Although Hollywood would like us to believe that bee swarms are dangerous, swarming bees rarely attack. When swarming, bees are actually looking for a new location to set up housekeeping. Therefore, they have nothing to protect. It is when a hive has been established for several months that the African bee is most defensive.
"The African honeybee is really only dangerous after a nest has been established about six months," Thoenes explained. "By six months, the colony is so big, and the bees so numerous, that they can be quite dangerous. If you let an African honeybee colony get established, you then have a time bomb waiting to go off."
The attack on the Phoenix farriers was such a case. Apparently, the ranch owner had European honeybees at one time. After abandoning his bee venture, the owner discarded his beekeeping equipment and hives behind a shed next to a corral. A swarm of African bees found the junk pile and set up house. One afternoon while the farriers were working, something agitated the bees and they attacked the men and horses. The farriers were able to escape by running away, but the horses were corralled and could not escape.
Although African bees swarm many times a year, only a portion of the bees--as many as 5,000 to 6,000--leave the colony in search of a new home. Swarming is how a colony reproduces, prevents overcrowding, and defends its existence against predators. Professional beekeepers, however, manage their European honeybee colonies to prevent overcrowding and swarming. When African bees do swarm, the bees might travel as far as 100 miles looking for a new home.
Because African bees are constantly on the move, Thoenes said it is just a matter of time before the bees move into other states with temperate winters. As of today, African honeybees have been confirmed in Texas, Arizona, New Mexico, and Southern California. The first positive identification of an African honeybee colony was in Navasota, Texas, in 1990. They were discovered in Arizona in 1994, and by 1995 African bees had colonized all or part of three California counties, Imperial, Riverside, and San Diego.
"They (African honeybees) have just had a greater chance to move into the Southwest states because they have migrated up Mexico's east and west coasts," Thoenes said. "If not controlled, they could easily spread throughout the southeast, particularly Florida, since it has the tropical heat and humidity that African honeybees prefer."
Although African bees have been detected in the most southern areas of New Mexico, most of New Mexico is safe from this pest. New Mexico's elevation is high enough to produce cold winters, which are deadly to the African honeybee.
Since any bee attack can be lethal, Thoenes recommends horsemen learn to watch and listen for bee activity while trail riding. Particularly watch the ground. African honeybees have an affinity for nesting in the ground, or in hollow objects low to the ground, i.e., hollow logs, old tires, animal burrows, junk piles, water meters, overturned flower pots, and even empty soda bottles. They also like to nest in abandoned buildings, under mobile homes, in eaves, mail boxes, and electrical boxes on utility poles. Be alert for groups of flying bees entering or leaving an entrance, opening, or crevice. Listen for buzzing sounds. Be especially alert when riding or climbing over, or around, rocks. Bees often nest under rocks or within rock crevices.
If you think you're approaching a bee hive, give the little winged creatures a wide berth. Move away immediately, at least 100 feet. Do not shoot, throw rocks at, try to burn, or to otherwise disturb the bees. If the colony is near a trail or area frequented by humans, notify the local office of the Parks Department, Forest Service, or Fish and Game Department. Although the bees might appear docile when you ride by, the next rider or hiker might unexpectedly provoke an attack.
Because the African honeybee nests so close to the ground, it is particularly sensitive to vibrations. Lawn mowers, weed whips, chain saws, or other machinery have triggered about 70% of the African bee attacks in Arizona. African bees also are agitated by loud noises and noxious odors spewed by machinery.
For those African honeybees nesting underground, or close to the ground, the vibration of passing horses might be sufficient to trigger an attack. When set upon by hundreds of bees, horses probably will bolt or buck.
"Quite often it is the second horse that is attacked because the vibration from the lead horse sets the bees off," Thoenes explained. "This is a particularly dangerous situation because if the rider falls off and gets hurt, or is knocked unconscious, the rider could be the target of the bees' agitation."
Fortunately for the unconscious rider in Tucson, the bees chose to pursue the horse rather than the downed rider.
When trail riding, Thoenes recommends riders wear light clothing. Dark colors are provocative to bees, particularly leathers and furs. When defending their nest, honeybees target objects that resemble their natural predators.
"Bears are an example of a bee's natural predator," Thoenes explained. "When the African bees come out to attack, the first things they look for are big dark things moving around. A horse is usually a big, dark-colored mammal, so the bees assume it is a predator. But unlike a bear's coat, a horse's coat offers no protection against stings."
Also, do not wear perfumes, perfumed shampoos, or body lotions, and avoid fly sprays with a "lemony" or citrus scent. Honeybees communicate using scents and tend to be quite sensitive to odors. Lastly, dogs should be kept on a leash or under close control. A dog bounding through the brush is likely to disturb a colony and be attacked. When the animal races back to its master, it will bring the attacking bees with it.
If you do stir up a bee attack, run or ride away fast. Do not stop to swat bees and do not flail your arms. Bees are attracted to movement and crushed bees emit a smell that will attract more bees. Also, do not jump into water. The bees will simply wait for you to surface. If you see someone being attacked by bees, encourage them to run away or seek shelter. Do not attempt to rescue them yourself. Call 911 if it appears to be a life-threatening attack.
"The secret to surviving an attack is to get away as quickly as you can," Thoenes said. "The bees are trying to drive you away from a nest. Don't argue with them."
If you are attacked and are stung more than 15 times, or feel ill, or if you have any reason to believe you are allergic to bee stings, seek medical attention immediately. The average person can safely tolerate 10 stings per pound of body weight. This means that 500 stings can kill a child. Children, the handicapped, and the elderly are most vulnerable to bee attacks because they can't, or don't know, to run away. Corralled, tied, or caged animals are also vulnerable. Have a veterinarian examine any horse suffering multiple stings, particularly on the muzzle, and/or in the nostrils.
If you suspect bees are nesting on your property, do not attempt to remove them yourself. Call a professional pest removal service. Thoenes offers such a service through his company, BeeMaster Inc. BeeMaster has four offices in Arizona, and he is in the process of franchising his bee detection and removal business.
BeeMasters also offers a preventive program that involves monitoring bee movements on a property using swarm traps. BeeMaster employees check the traps weekly for signs of African honeybee infestation. Invented by Thoenes and USDA scientist Justin Schmidt, the swarm traps are the predominate means of monitoring bee activity.
"People should not over react to bees," Thoenes concluded. "Bees that are managed by professional beekeepers are not a problem. Beekeepers regulate the genetics of their colonies very carefully. The bees you see in the white boxes are nice, quiet, non-violent European bees. People have to understand that the best way to keep African bees from establishing a colony in an area is to have a strong, vibrant, European honeybee community."
About the Author
POLL: Visits from the Vet