Africanized Honey Bees: Prevention and Control Africanized Honey Bees

Reminder from NC State Extension By Dr. David Tarpy Originally Published February 1, 2016

Africanized Honey Bees: Prevention and Control Africanized Honey Bees


For the past 50 years, the Africanized honey bee (sometimes referred to as the “killer” bee by sensationalist media stories) has been a public health concern in South and North America. Initially imported to Brazil in the mid-1950s, this invasive species spread northward into the United States by the early 1990s. While Africanized honey bees have not yet become established in North Carolina, their recent detection in Florida and other gulf-coast states makes their arrival in the coming years fairly likely.

To prepare for the introduction and possible establishment of the Africanized honey bees in this state, it is necessary for residents of North Carolina to become familiar with means of prevention and control of nuisance honey bee colonies. The following are some recommendations on how to reduce the chances of encountering Africanized bees, and what to do if they are encountered.

For Homeowners and the General Public

Africanized honey bees can be a public health concern because they are more likely to sting than “typical” honey bees. Like their European counterparts, however, Africanized honey bees will usually become defensive only when provoked or guarding their nest. Thus to prevent stings from honey bees, it is important to do two things. First, do not swat at bees flying around you, since it will likely provoke them and increase the chances that they will sting you. Second, reduce the likelihood that an Africanized honey bee colony will become established on your property by removing potential nest sites.

Means of prevention

“Bee-proof” your house. Most Africanized bees do not live in boxes managed by beekeepers, but rather in structures or other man-made cavities. With a little know-how, these potential nest sites can be removed or made unsuitable for bee habitation.

Carefully inspect your house and other structures for holes or cracks that could potentially lead to an internal cavity, wall space, attic, or crawl space, as bees can build their nests in any of these places. Prevent access to these areas by sealing the cracks with wire-mesh screen, caulk, or an expanding foam such as “Great Stuff” (Figure 1). Any gap greater than 1⁄8 of an inch could possibly provide access to bees, so be sure to seal any such crevice sufficiently to prevent bees from moving in.

Inspect other potential nesting sites around your house as well. In other regions of the country, Africanized bees have been known to inhabit such man-made cavities as tool sheds and water meters (Figure 2), since they often have small entrance holes and can provide an ideal space for a nest. Be sure to also clean up any junk piles or other debris that may create sheltered nesting sites. In particular, abandoned tires, over-turned flower pots, or inverted metal cans (Figure 3) serve as excellent nesting cavities for Africanized bees.

Check for unusual honey bee activity. A few dozen bees visiting your flower beds is very typical and indeed beneficial for your garden. Bees can also collect water from bird baths or swimming pools, particularly during the heat of the summer. However, if hundreds of bees are clustered together or seen entering and exiting a single hidden location, it may be a sign that a colony has become established. If you are unsure, call a local beekeeper to come investigate. Contact your local Cooperative Extension center for a list of potential local beekeepers. Established colonies are different from exposed “swarms” hanging off of a tree limb. Swarm clusters are bees in search of a new nesting site, and are usually much less defensive that those protecting a hive. As such, swarm clusters (either African or European) are not very defensive, and they will likely fly off to their new home within a couple of days. Again, contact a local beekeeper if you locate a bee swarm.

Don’t keep pets tied or tethered. If you have pets, livestock, or other animals living outdoors, you may consider taking precautions for them as well. Mass-stinging incidents of pets has occurred by Africanized bees in other areas of the country where the animals had no opportunity to escape or find shelter from pursuing bees.

Know the difference between honey bees and wasps. Many people mistakenly believe that anything that flies and potentially stings is a “bee.” As a result, many wasp species—such as yellow jackets, European or Japanese hornets, and bald-faced hornets—are often mistaken for honey bees. In fact, many of these wasps can be even more defensive than Africanized honey bees, and many of the preventative measures outlined above can help reduce the chances that they, too, may become established on your property.

Means of Control

Keep your distance. If you locate a nest on your property, note its location but don’t approach it. Bees and wasps are much more likely to react in defensive of their hive, so do not pose a threat to them.

Call a professional. Contact a licensed Pest Control Operator in your area. They will assess the problem, determine if they are honey bees or another species, and take appropriate action. If possible and appropriate, they will send in a sample of the bees to the North Carolina Department of Agriculture & Consumer Services so that they can be diagnosed as Africanized honey bees or typical European honey bees. We do not recommend that you exterminate the bees yourself.

Remove the combs to prevent further damage. Fermenting honey and spoiling wax can harm the structure in which the nest was located, so it is important to remove the combs as well as the bees. This often involves removing walls to excise the nest, as well as repair work after the combs are removed. Because larger nests can do greater harm, it is best to deal with the issue sooner rather than later.

For mass stinging incidents or allergic reactions, call 911. In an emergency, seek immediate medical assistance. The fire department may respond with foam or surfactant spray to calmly and safely kill the stinging bees.

Figure 1. A “bee gap” around a water pipe. Seal the crack with wire mesh to prevent bees from moving in.

Figure 2. Water meters make good homes for bees.

Figure 3. Inverted pails or flower pots should be removed to eliminate potential nesting sites for bees.

Fig 1 2 3.jpg

For Beekeepers

Again, Africanized bees do not live in beehives but rather in natural or man-made cavities. As such, beekeepers are on the front lines in our attempts to reduce the impact of Africanized bees. In short, beekeepers are part of the solution, not the problem.

Means of prevention

  • Mark all queens with paint or numbered tags, no exceptions

  • Regularly check hives; don’t let them “feralize”

  • Properly store all bee equipment; don’t let swarms move into empty hives

  • Be on the look out for parasitic swarms (Africanized bees can invade a colony of European honey bees and take over the nest)

Means of control

  • Requeen any unusually defensive colonies and call your local NCDA&CS Apiary inspector so that they may take a sample

  • Soapy water in a spray bottle, rather than aerosol insecticide, is usually a better method to kill suspect bees if they become a nuisance

  • Educate public and other beekeepers about the benefits of honey bees and how to avoid contact with Africanized bees

Different Types of Honey Bees

The Different Types of Honey Bees


Honey bees, like all other living things, vary among themselves in traits such as temperament, disease resistance, and productivity. The environment has a large effect on differences among bee colonies (for example, plants in different areas yield different honey crops), but the genetic makeup of a colony can also impact the characteristics that define a particular group. Beekeepers have long known that different genetic stocks have distinctive characteristics, so they have utilized different strains to suit their particular purpose, whether it be pollination, a honey crop, or bee production.

What Is a Bee Stock?

The term “stock” is defined as a loose combination of traits that characterize a particular group of bees. Such groups can be divided by species, race, region, population, or breeding line in a commercial operation. Many of the current “stocks” in the United States can be grouped at one or more of these levels, so the term will be used interchangeably, depending on the particular strain of bees in question.

Wide variation exists within stocks as well as among them. Any generalities about a particular stock should be treated with caution, since there are always exceptions to the rule. Nonetheless, the long and vast experience of beekeepers allows some oversimplifications to be made in order to better understand the different types of bees available. The following is a brief overview of some of the more common commercially available honey bee stocks in the United States.

Comparison of bees and their traits

Comparison of bees and their traits

The Italian Bee

Italian honey bees, of the subspecies Apis mellifera ligustica, were brought to the United States in 1859. They quickly became the favored bee stock in this country and remain so to this day. Known for their extended periods of brood rearing, Italian bees can build colony populations in the spring and maintain them for the entire summer. They are less defensive and less prone to disease than their German counterparts, and they are excellent honey producers. They also are very lightly colored, ranging from a light leather hue to an almost lemon yellow, a trait that is highly coveted by many beekeepers for its aesthetic appeal.

Despite their popularity, Italian bees have some drawbacks. First, because of their prolonged brood rearing, they may consume surplus honey in the hive if supers (removable upper sections where honey is stored) are not removed immediately after the honey flow stops. Second, they are notorious kleptoparasites and frequently rob the honey stores of weaker or dead neighboring colonies. This behavior may pose problems for Italian beekeepers who work their colonies during times of nectar dearth, and it may cause the rapid spread of transmittable diseases among hives.

The German Bee

Honey bees are not native to the New World, although North America has about 4,000 native species of bees. Honey bees were brought to America in the 17thcentury by the early European settlers. These bees were most likely of the subspecies A. m. mellifera, otherwise known as the German or “black” bee. This stock is very dark in color and tends to be very defensive, making bee management more difficult. One of the German bees’ more favorable characteristics is that they are a hardy strain, able to survive long, cold winters in northern climates. However, because of their defensive nature and their susceptibility to many brood diseases (such as American and European foulbrood), this stock lost favor with beekeepers well over a century ago. Although the feral bee population in the United States was once dominated by this strain, newly introduced diseases have nearly wiped out most wild honey bee colonies, making the German bee a rare stock at this time

The Carniolan Bee

The subspecies A. m. carnica, from middle Europe, also has been a favored bee stock in the United States for several reasons. First, their explosive spring buildup enables this race to grow rapidly in population and take advantage of blooms that occur much earlier in the spring, compared to other stocks. Second, they are extremely docile and can be worked with little smoke and protective clothing. Third, they are much less prone to robbing other colonies of honey, lowering disease transmission among colonies. Finally, they are very good builders of wax combs, which can be used for products ranging from candles, to soaps, to cosmetics.

Because of their rapid buildup, however, carniolan bees tend to have a high propensity to swarm (their effort to relieve overcrowding) and, therefore, may leave the beekeeper with a very poor honey crop. This stock requires continued vigilance to prevent the loss of swarms.

The Caucasian Bee

A. m. caucasica is a race of honey bees native to the foothills of the Ural mountains near the Caspian Sea in eastern Europe. This stock was once popular in the United States, but it has declined in regard over the last few decades. Its most notable characteristic is its very long tongue, which enables the bees to forage for nectar from flowers that other bee stocks may not have access to. They tend to be a moderately colored bee and, like the Carniolans, are extremely docile. However, their slow spring buildup keeps them from generating very large honey crops, and they tend to use an excessive amount of propolis—the sticky resin substance sometimes called “bee glue” that is used to seal cracks and joints of bee structures—making their hives diffi- cult to manipulate.

The Buckfast Bee

In the 1920s, honey bee colonies in the British Isles were devastated by acarine disease, which now is suspected to have been the endoparasitic tracheal mite Acarapis woodi. Brother Adams, a monk at Buckfast Abby in Devon, England, was charged with creating a bee stock that could withstand this deadly disease. He traveled the world interviewing beekeepers and learning about different bee strains, and he created a stock of bees, largely from the Italian race, that could thrive in the cold wet conditions of the British Isles, yet produce good honey crops and exhibit good housecleaning and grooming behavior to reduce the prevalence of disease. Bees of this stock are moderately defensive. However, if left unmanaged for one or two generations, they can be among the most fiercely defensive bees of any stock. They also are moderate in spring population buildup, preventing them from taking full advantage of early nectar flows.

The Russian Bee

One of the newer bee stocks in the United States was imported from far-eastern Russia by the US Department of Agriculture’s Honey Bee Breeding, Genetics, and Physiology Laboratory in Baton Rouge, Louisiana. The researchers’ logic was that these bees from the Primorski region on the Sea of Japan, have coexisted for the last 150 years with the devastating ectoparasite Varroa destructor, a mite that is responsible for severe colony losses around the globe, and they might thrive in the United States. The USDA tested whether this stock had evolved resistance to varroa and found that it had. Numerous studies have shown that bees of this strain have fewer than half the number of mites that are found in standard commercial stocks. The quarantine phase of this project has been complete since 2000, and bees of this strain are available commercially.

Russian bees tend to rear brood only during times of nectar and pollen flows, so brood rearing and colony populations tend to fluctuate with the environment. They also exhibit good housecleaning behavior, resulting in resistance not only to varroa but also to the tracheal mite.

Bees of this stock exhibit some unusual behaviors compared to other strains. For example, they tend to have queen cells present in their colonies almost all the time, whereas most other stocks rear queens only during times of swarming or queen replacement. Russian bees also perform better when not in the presence of other bee strains; research has shown that cross-contamination from susceptible stocks can lessen the varroa resistance of these bees.

Other Notable Stocks

Many other honey bee stocks are worth noting:

The Minnesota Hygienic stock has been selected for its exceptional housecleaning ability, significantly reducing the negative effects of most brood diseases.

The VSH, or the "Varroa Sensitive Hygiene" stock (used to be named the SMR stock, referring to “Suppression of Mite Reproduction”), also was developed by the USDA honey bee lab in Louisiana by artificially selecting commercial stocks for mite resistance. While not an independently viable stock on its own (because of inbreeding), the VSH trait has been incorporated into other genetic stocks so that these stocks may also express this highly desired characteristic.

The Cordovan bee is a type of Italian bee that has a very light yellow color, which is more attractive to many beekeepers.

Numerous hybrid stocks are also available commercially:

The Midnite bee was developed by crossing the Caucasian and Carniolan stocks, hoping to maintain the extreme gentleness of both strains while removing the excessive propolis of the Caucasians and minimizing the swarming propensity of the Carniolans.

The Starline was developed from numerous strains of the Italian stock by Gladstone Cale of the Dadant Bee Company. It was once favored by commercial beekeepers because of its tremendous honey yields, particularly in clover, but the popularity of this stock has declined in recent decades.

The Double Hybrid is a cross of the Midnite and the Starline.


While a tremendous amount of variation remains within and among the different bee stocks, some generalities still can be made. Bee differences can be used to advantage by beekeepers, depending on what traits interest them, so using different stocks can be a powerful tool at the beekeeper’s disposal. There is no “best” strain of bee, as the traits favored by one beekeeper may differ significantly from another’s choice. Thus, it is best for each beekeeper to experience the characteristics of the different bee strains first hand and then form an opinion about which stock best fits his or her situation.

For more information on beekeeping, visit the Beekeeping Notes website.

David R. Tarpy
Professor and Extension Apiculturist
Department of Entomology, Campus Box 7613
North Carolina State University
Raleigh, NC 27695-7613
TEL: (919) 515-1660
FAX: (919) 515-7746

Jennifer J. Keller
Apiculture Technician
Department of Entomology, Campus Box 7613
North Carolina State University
Raleigh, NC 27695-7613
TEL: (919) 513-7702
FAX: (919) 515-7746

NC State Extension
Author David Tarpy,
Professor and Extension Apiculturist