Killer Bees: Swarms and Attacks in Arizona

Worker Africanized Honey Bees at work on the honeycomb
Martin Harvey / Getty Images

Off the top of your head, if you try to list the worst biting pests in Arizona, probably topping that list would be rattlesnakes, scorpions, or even fire ants. However, killer bees are a big problem in Arizona—mostly during bee season from March to October, which tracks with warmer temperatures. It is important for you to know what to do if you encounter a swarm.

Aggressive Africanized Honey Bees

Killer bees are actually referring to Africanized honey bees, which are an aggressive hybrid of an African honey bee that has been bred with a Brazilian honey bee. If you encounter a swarm or get bitten by a bee, do not panic. 

If you or someone you know is stung and experiencing shortness of breath or difficulty swallowing, call 911 or seek immediate medical attention.

Killer bees are considered a nuisance bee because they will launch an attack on people or animals that unintentionally stray into their territory. This aggressive variety of bee does not have to be disturbed or provoked; even simple noises or vibrations have been known to cause an attack. This type of bee has been known to a chase a person for up to a quarter of a mile.

In the 1990s, swarms of the crossbred bees reached the United States. In 1993, the hybrid bees became a problem for Arizona and New Mexico. According to the University of Arizona, if you encounter a honey bee, it is safe to assume that it is the Africanized variety.

How Dangerous Is the Killer Bee?

The sting of the Africanized honey bee is no more potent than your garden variety honey bee and they look pretty much the same. There is no concrete number of stings that are safe or that are lethal. 

According to the Merck Manual medical reference: 

"The average unsensitized person can safely tolerate 22 stings per kilogram of body weight; thus, the average adult can withstand greater than 1000 stings, whereas 500 stings can kill a child."

Twenty-two stings per kilogram are roughly 10 stings per pound of body weight. There is a documented case of a man who survived more than 2,000 bee stings. There are others who are very sensitive or allergic to bee stings. Each year in the U.S. up to 100 people die from bee stings, many of whom had allergic reactions to the stings. Pets are also vulnerable. 

Killer bees get the "killer bee" moniker because they are more easily provoked, quick to swarm, attack in greater numbers, and pursue their victims for greater distances. The killer bee colony can remain agitated longer. These colonies can be very large, and they are not particularly selective about the location of their hives. 

If You Are Stung

If you or someone you know is stung, experiencing shortness of breath, difficulty swallowing, fainting, vomiting, turning pale, or experiencing a rapid or slowing heart rate or pulse, call 911 or seek immediate medical attention. Anyone who gets 30 or more bee stings should seek medical attention. 

For the general care and treatment of Africanized honey bee stings, scrape stingers off as soon as you get to an indoor safe place. Wash the sting site with soap and water, apply a topical antibiotic, or ice wrapped in a cloth to soothe the discomfort. 

Do Not Kill the Killer Bees

Although this bee can be aggressive, all types of bees remain important and productive insects for the environment, which is why bee fumigation and insecticides are discouraged.

If you notice a colony in a populated area, call a bee specialist or the local fire department to assess and handle the colony relocation. Pay attention if you see a few bees coming in and out of cracks in walls, utility boxes, or other enclosed places. Do not try to remove a beehive without professional help. Contact the Better Business Bureau for beekeepers, bee removal services, bee supplies, or pest control services. If you see a beehive on public property or in a park, contact the city in which it is located and let them know so they can take appropriate action.

Where Bees Like to Live

Killer bees hives or colonies are likely to develop near canals, drainage ditches, and retention basins because they like to be near water. The Africanized queen bee can lay up to 1,500 eggs a day. Sometimes, when they sense rain, the hive may swarm.

In Arizona, the killer bee colonies have grown; the more aggressive colonies are those that have survived drought periods. The summer is the peak period for bee attacks because there is less honey, and the bees become more protective of their hives.

How to Avoid a Swarm

Check the perimeter of your house regularly for bee colonies. Check storage sheds, dog houses, meter boxes, flower pots, trees, shrubs, piles of wood or debris, and crevices. Be careful moving or cleaning up debris or items that have been lying around outside the house. Seal cavities and crevices that might make for good hive location. Install a cover over the chimney when not in use.

Keep pets and children inside when using lawn mowers, clippers, blowers, or any other equipment that makes noise or could inadvertently disturb a beehive. Never pen or tether animals near beehives.

Wear light-colored clothing around your home, when hiking, or visiting unknown areas. Do not wear floral or citrus perfumes or aftershave when doing yard work or hiking.

If a Bee Attack Occurs

Have an escape plan in the event of a bee attack. Do not play dead or swat at the bees. If you notice a swarm coming your way, quickly get into a house, car, tent, or other enclosure. Close any doors or windows.

The key is to run away as fast as you can in a straight line. Bees are slow fliers. Most healthy people should be able to outrun the bees. Be prepared to run up to the length of two football fields.

Do not jump into a pool or underwater. The bees will wait until you surface for air to attack. Your face will be the first area to be stung.

Protect your face to prevent stings to the eyes, nose, and in the mouth. Bees attack where carbon dioxide is expelled. Facial stings are much more dangerous than stings to the body. Pull your shirt over your head if no other protection is available.

Killer Bees History

In 1956, the African bees were brought to Brazil so that scientists there could try to develop a honey bee better adapted to tropical areas. Unfortunately, some of the bees escaped and began breeding with local Brazilian honey bees. Since 1957, these bees and their hybrid offspring, Africanized honey bees, have been multiplying and migrating to other regions.

The first swarm of Africanized bees in the United States was documented in 1990 in Hidalgo, Texas. They were found in Arizona and New Mexico in 1993, California in 1994, and in Nevada in 1998. Africanized honey bees can be found in most of mid and southern Texas, about one-third of New Mexico, all over Arizona, the southern half of New Mexico, and the southern third of California. 

Killer bees continue to migrate northward and have reached most of the southern U.S. up to the Chesapeake Bay area.

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