Cooperative Extension – 8819
The University of Arizona – College of Agriculture – Tucson, Arizona 85721
E. H. ERICKSON(1), B. J. ERICKSON(2), H. H. LAIDLAW(3) and L. MOORE(4)
The “Africanized” honey bee is a hybrid between domesticated strains of mostly European honey bees and African honey bees; African bees were introduced into the Americas via Brazil in 1957. Africanized bees may be identical in appearance to most domestic bees but may be slightly smaller than some. They are currently migrating northward through Mexico and could reach southern Arizona late in 1990 or in 1991, if not delayed or modified by the current U.S.-Mexican Africanized honey bee program.
The migration of Africanized bees is not the invasion of a single well-defined race of bees. Rather it is the flow of a variable population into a larger, even more variable population of domesticated honey bees. Domestic honey bees are a composite of several artificially selected races while Africanized bees more closely resemble populations found in nature. This hybrid strain of honey bees exhibits extremes in
a wide range of behaviors. Some colonies may become unusually defensive and it is the inclination of such colonies to sting excessively in self defense that concerns officials, beekeepers and the public at large.
Domestic bees, the product of centuries of selection by man, appear vulnerable to pressures leading to reversion to the wild type. The problem of African gene flow can be solved by reversing this flow – by maintaining positive selection pressure favoring domestic bees. Fortunately, we already know how to do this. What we must do is insure that available techniques are employed uniformly at all levels throughout the beekeeping industry.
The purpose of this bulletin is to provide both beekeepers and the public with information to help them cope, if necessary, with the Africanized honey bee. It must be recognized that the United States will rely heavily upon the beekeeping industry to mitigate the impact of this strain of honey bees. However, it is equally important to note that the public’s assistance and cooperation with keepers of domestic honey bees is essential. Reaction to a potential problem that may never materialize must be avoided. If the Africanized honey bee does arrive, the public is encouraged to be careful but tolerant during the transition period after which the undesirable behavior will diminish.
There are several measures that can be taken to offset the impact of this undesirable strain of honey bees. These include beekeeper implementation of certain honey bee colony management strategies, suppression of highly defensive behavior in feral (wild) honey bee colonies, and development of public education/information programs. Listed below are state-of-the-art approaches and strategies recommended in understanding and preparing for the Africanized honey bee.
(1) Center Director, USDA, ARS, Carl Hayden Bee Research Center, 2000 E. Allen Road, Tueson, AZ 85719.
(2) Research Associate, 5105 W. Albatross Place, Tucson, AZ 85741.
(3) Professor Emeritus, University of California, Department of Entomology, Davis, CA 95616.
(4) Extension Entomologist, University of Arizona, Turson, AZ 85721.
Africanized Honey Bees and the Public
Domestic honey bees are largely, but not entirely descendants of European bee races. Domestic honey bees, like other farm animals, have been selected for gentleness, productivity and size. The continued maintenance of domestic honey bee populations is our best defense against Africanization. The single most counterproductive reaction to the potential influx of Africanized bees would be to remove domestic honey bee colonies, especially those kept by hobbyists, from urban, recreational and agricultural areas. Losses of colonies over which beekeepers have genetic control could simply accelerate and assure Africanization in the form of feral colonies which may not be controlled.
It is impossible to accurately predict if and where Africanized honey bees will become established. However, a good rule of thumb is that they will thrive where domestic bees have been kept successfully. Generally, these are areas near (within 8 km, [5 miles]) available water and adequate forage (blooming plants including trees) throughout most of spring and summer. Also, these are likely to be areas in which the mean high temperature in winter months exceeds 66º F (19º C). However, the Africanized bee may overwinter where mean high temperatures fall to 60º F (16º C) or below.
Experience in South and Central America suggests that where domestic bees are abundant and remain well managed, and where constant selection pressure is applied through requeening, the Africanized strain will soon become domesticated and its impact will be minimal. If Africanized bees become established in remote areas with few domestic bees, colonies will exhibit varying levels of undesirable behavior. In these places unmodified Africanized bees may remain indefinitely. Since the Africanized strain will, for the first time, encounter high densities of domesticated bees in Mexico, expectations regarding the impact of these bees in the United States will become more clear as time passes.
Honey bees clearly identifiable as Africanized can be highly defensive, and difficult to work with even for beekeepers. However, many Africanized colonies are more manageable (with normal protective clothing) and they possess other desirable traits. Africanized honey bees readily interbreed with domestic strains thus lessening their undesirable behaviors.
Most people are uneasy around honey bees because they erroneously believe them to be aggressive when in fact bees attack only if they perceive a threat or are defending the hive. Africanized honey bees are particularly sensitive to disturbance. There are a number of precautions one can take when working with or around bees to avoid provoking a defensive response and thereby minimize the chances of being stung. These precautions are deeply ingrained in the work habits of experienced beekeepers, yet knowledge of them can benefit all who encounter bees.
To avoid serious injury from highly defensive honey bee colonies the public should:
1. Remain cautiously aware of the potential presence of colonies of defensive honey bees, particularly in remote areas, while realizing that individual foraging bees are NOT a threat.
2. Keep a respectful distance away from honey bee nests and swarms. Do not under- or overestimate the hazard. Treat them just as you do venomous animals such as snakes, other insects and spiders.
3. When hiking or camping in remote or recreational areas, wear tight-fitting, light-colored clothing, avoid the use of perfumes, fragrant lotions or hair sprays, and don’t swat at flying bees. See the section entitled “How to Avoid Being Stung by Honeybees” for more do’s and dont’s.
4. Do not intentionally disturb or provoke honey bee swarms or nests. Unmanaged colonies nest in cavities such as ground holes, rock crevices, hollow trees, discarded tires and metal power poles. Saguaro cactus cavities may also be utilized by honey bee colonies.
5. If a swarm or colony of honey bees suddenly appears in or around your home or work place, seek professional help in removing it. Do not attempt to remove it yourself.
6. If attacked unexpectedly, make as rapid an exit as possible and keep running until free of the bees (perhaps 0.8 km, [1/2 mile]). Cover your head with a shirt or whatever is available as stings in this area of the body represent the greatest health hazard. Remove stings as quickly as possible by scraping them away. To avoid additional stings, mask the alarm odors at the site of the sting by puffing smoke over it or by rubbing it with grass, mud, or whatever is handy.
7. Seek medical attention as soon as possible, especially after receiving multiple stings. Persons highly sensitive to bee stings (approximately one-half to one percent of the populace) should avoid areas where bees may be a problem and carry appropriate medication (sting kit) at all times.
How to Avoid Being Stung By Honey Bees
Beekeepers and the general public alike should be aware of the following measures that may help to avoid honey bee stings:
Clothing: Wear light-colored cotton or polyester clothing. Avoid floppy clothing such as shirt sleeves and tails. Tuck pants into boots. The ankles are frequently stung when the socks are dark. Remove shiny objects such as rings and wristwatches. Shiny objects attract the bees’ attention and accent motion. Leather wristwatch bands can also be offensive to bees.
The natural enemies of bees include skunks and bears, thus wool and other fuzzy fabrics evoke a defensive response, as do dark colors. Pets may also provoke honeybees because of resemblance to natural enemies.
Body Odors: The scents of many perfumes, soaps, after-shave lotions, cosmetics, and hair treatments are offensive to bees and often provoke them. Use these items sparingly if at all when you may be around bees. Certain individuals seem to be singled out by attacking bees. There is some suspicion that personal body odors, perhaps undetected by humans, may be responsible for this unwanted attention. Persons who repeatedly have problems with bees should avoid areas of bee activity.
Motion: Bees’ eyes readily detect motion and bees are threatened by rapid movements. Beekeepers try to work at a moderate pace in a sure-handed fashion.
- Avoid rapid or jerky movements.
- Don’t swat at flying bees.
- Don’t disturb, harass, or bump colonies.
- Don’t stand in front of the colony entrance or in the flight path.
Environmental Conditions: Whenever possible, beekeepers should work bees on bright, sunny days, and recognize that the mood of bees becomes more irascible on dreary days.
Colonies located in heavily protected (shady) or low-lying areas are frequently more sensitive to disturbance than colonies in open areas. This may be partly due to frequent disturbance from animals, such as skunks.
Certain colonies, races or strains of honey bees are more irascible than others and can be expected to be ornery under any circumstance. Queenlessness, disease, or pesticides can cause normally gentle bees to become more difficult.
Protecting Arizona’s Beekeeping Industry
The honey bee queen normally mates with from seven to 20 drones. Hence, each colony is composed of numerous step- or subfamilies with varying degrees of relatedness (Fig. 1). The queen contributes 50 percent of the genes of the whole colony but individual workers and daughter queens do not receive exactly the same complement of genes from the queen – only a sample of all the queen’s genes. Each drone mate contributes 50 percent of the genes of only the subfamily he sires. Thus, the queen imparts variation within subfamilies, drones impart variation between subfamilies, and both impart variation within a colony and between colonies. Out of the genetic mixture called a colony, one must know the parentage of the queen and that of each of her mates in order to correctly classify the total phenotype of a given colony (e.g. percent Africanized vs. domestic). Obviously, no two colonies (or workers or worker subfamilies within each colony) are exactly alike.
Domestic and Africanized honey bees are merely strains of the same species. It is possible that strains of small, dark domestic honey bees could be misidentified as Africanized, particularly when characteristics other than defensive behavior are used in the identification process. Moreover, data must be gathered that will allow assessment of the extent and impact of Africanization. Therefore, to protect beekeepers and colonies, and the public interest, certain initiatives should be undertaken:
1. Beginning immediately, samples of worker bees should be taken from both domestic and feral colonies. The samples taken should be examined and additional bees stored by an appropriate agency as voucher specimens for future reference.
2. Existing data on the incidence of swarming, honey production, etc. now available from various agencies should be compiled. These data can be used later in the assessment of impact of Africanization.
3. Losses of honey bees from pesticide use should be avoided. Honey bee colonies, particularly feral colonies, lost due to pesticides or any other mortality factor may well be replaced by bees of the Africanized strain.
Management Strategies for Beekeepers
Africanization of a population takes place in two ways: 1) Africanized drones mate with European queens which are eventually superseded by their daughters and the process is repeated; and 2) Africanized swarms may invade colonies which have unmated or failing queens or are queenless.
The process of Africanization results in colonies with a wide range of behavioral characteristics. Only a minority of colonies are consistently unmanageable and extremely defensive. Most honey bee colonies, whether Africanized or domestic, are behavioral intermediates between the highly defensive and docile extremes. These intermediate colonies are manageable and productive although some exchanges in management practices may be necessary.
The honey bee queen mates 14.6 – 36.5 m (40-100 feet) above the ground and at 24 km/hr (15 mph); hence, it is difficult to control natural mating. Domestic honey bee colonies can be maintained free of African genes simply by keeping colonies queenright and monitoring the identity of the non-Africanized resident queen. If a queen bee of unknown origin (an unmarked queen) appears in the hive, she must be replaced, preferably with a marked laying queen of known origin, or with a virgin queen in a “ripe” queen cell.
There are approximately 210,000 beekeepers in the United States that keep bees as a hobby (1-24 colonies) or as a sideline (25-299 colonies) for supplemental income. Fortunately, most of these colonies are in or around urban areas. These beekeepers should:
1. Be strongly encouraged to keep their colonies in place.
2. Requcen their colonies annually with marked queens. Do not clip queens because if colonies swarm they will likely become feral bees and continue to contribute European drones.
3. If a colony is identified as unusually defensive and therefore suspect, Africanized, or has a failing queen, requeen it immediately, preferably with a mated queen. Or depopulate it. Don’t allow suspect colonies to rear drones, or put a queen excluder over the colony entrance to prevent drone flight. Requeening is the most effective way to remove the immediate potential for Africanization in an area. Depopulation of particularly ornery colonies may be considered in densely populated areas if the colony is reestablished immediately using gentle stock.
4. Keep 1 or 2 frames of drone comb or the equivalent for drone production in every colony. Early spring feeding with pollen supplement will stimulate early drone production which may be desirable in many areas.
5. Practice good colony management. Keep colonies well-fed, strong, queenright, and disease free. Strong colonies are more stable. Weak colonies should be united. Keep colonies in hives with full depth brood chambers and ample space to minimize swarming and absconding.
6. Apiaries with properly managed colonies can be allowed to remain in place. However, if constant selection pressure for more gentle, manageable strains is not practiced, apiaries should be relocated 200 meters (220 yards) from roadsides and 400 meters (440 yards) from homes and animals.
7. Limit apiaries to 25-50 colonies.
8. Avoid robbing. Robbing screens may be used on hive entrances.
9. Provide colonies with moderate shade and water. Fence apiaries or place colonies behind bushes or screens that are at least 1.8 meters (6 feet) high. Do not place more than one colony on a hive stand, so that working with one colony will not disturb an adjacent colony.
10. Store indoors all unused or vacant hive equipment. The storage area must be bee tight. Destroy all abandoned or unusable hives. Because Africanized bees swarm more frequently, they will occupy nearly any cavity that will serve as a nest site.
11. If Africanized bees arrive, capture and destroy immigrating swarms. Do not keep captured swarms!
Although comparatively few in number (1,600), commercial beekeepers (300 or more colonies) are responsible for about 50 percent of all (4.1 million) managed honey bee colonies in the United States. Most of these colonies are located in rural areas, usually on farms or on state and Federal land.
Commercial beekeepers should adhere to the recommendations above. However, since they may find certain of these impractical or economically unfeasible, they may wish to consider the following alternatives:
- Requeen colonies annually with queens in queen cells or marked virgin queens of known origin. First generation workers ~e.g. daughters of domestic queen x Africanized drone(s)] are of little consecuence because they are not reproductives. However, they must not be allowed to rear their own queen.
- Use body color markers and other traits as good but not absolute indicators of the integrity of domesuc strains.
Queen producers should:
- Vigorously select for desirable characteristics in domestic strains for queen mothers.
- Graft only from known, marked queen mothers.
- Identify and utilize drone mating (congregation) areas where possible. Maintain mating yards in areas dominated by domestic (preferably their own) drones.
Control of Africanized Bees in Remote Areas
Prior experience in South and Central America suggests that most serious stinging incidents were instigated by feral (wild) bees. Moreover, the number of these incidents declines over time following the initial period of Africanization.
Control of Africanized bees in remote areas and in state and national parks, where there are few colonies of domestic bees, should be most difficult if not impossible. Scientists are attempting to develop control strategies for the destruction of objectionable feral colonies, but Africanization of areas distant from managed apiaries may have to be accepted.
Alternatively, the undesirable behavior of feral honey bee colonies in such areas that can be reached can be mitigated by placing and maintaining strong, well-managed colonies of domestic bees at 1.6 km (1 mile) intervals particularly in recreational areas. Their purpose will be to produce drones, but swarming could also be encouraged. These strategies will lead to dilution of the undesirable strain of bees.
If Africanized bees arrive in Arizona, knowledgeable beekeepers will be able to cope with Africanization and eliminate undesirable behavioral traits such as defensiveness from their colonies and apiaries. However, to succeed, the public must provide beekeepers with the latitude to do their work. Those beekeepers who are inadequately trained must be taught certain basic principles and techniques. Sources of information on the Africanized bee must be established.
The following approaches are recommended:
1. Develop the necessary beekeeper educational programs to assure a working knowledge of and implementation of essential honey bee colony management strategies.
2. Develop a strong program for public education that emphasizes the importance of the cautions and problem solving approaches listed herein. Great emphasis should be placed on the need to maintain or increase a strong presence of domestic honey bees with desirable traits in populated and recreational areas, and to remove immediately all unmanaged colonies and swarms when they are discovered.
3. Establish an Africanized bee hotline for information and advice. Such a resource could be managed either by members of the Arizona Commission of Agriculture and Horticulture or the Arizona Beekeepers Association.
“Africanized” Bees: Although some experts disagree, it is generally believed that the Africanized bee is a highly variable hybrid strain formed between domesticated bees and African bees imported into Brazil in 1957.
Colony: The aggregation of bees living within the hive (domicile).
Domestic Bees: Honey bees largely but not entirely of European origin that have been selected and bred and are now managed by beekeepers.
Feral: Existing in nature, wild, not domesticated.
Hive: The domicile inhabited by the colony.
The authors wish to acknowledge R. Page, M. Spivak and 0. Taylor, all of whom contributed greatly to the thinking set forth in this bulletin. We also wish to thank D. Byrne and F. Werner for reviewing the manuscript.
Dejong, D. 1984. “Africanized bees now preferred by Brazilian beekeepers.” Amer. Bee J. 124: 116-118.
Erickson, E. H., Jr., B. J. Erickson and A. M. Young. 1986. “Management strategies for ‘Africanized’ honey bees: Concepts strengthened by our experiences in Costa Rica. Parts I and II.” Glean. Bee Cult. 114(9): 456-457, 459; and 114(10): 506-507, 534.
Kerr, W. E. 1966/67. “Solucao e criar uma raca nova.” [The solution is to breed a new race.] Guia Rural 1966/67 p. 20-22.
McDowell, R. 1984. The Africanized Honey Bee in the United States. What will happen to the U. S. beekeeping industry?” U. D. Dept. Agric. Econ. Res. Serv., Agric. Econ. Rpt. No. 519, 33 p.
Laidiaw, H. H., Jr., and R. E. Page, Jr. 1986. “Mating Designs. 1. Complexities of honey-bee breeding,” p. 323-344 In T. E. Rinderer, (Ed.). Bee Genetics and Breeding, Academic Press, Orlando, FL.
Spivak, M. 1988. “The Africanization Process in Costa Rica.” In the “African” Honey Bee. eds. D. J. C. Fletcher and M. D. Breed, Westview Press, Boulder, CO.
Taylor, 0. R., Jr., 1985. “African Bees: Potential impact in the United States.” p. 15-24 Bulletin of the Entomological Society of America 31(4).
Taylor, 0. R., Jr. 1988. Ecology and Economic Impact of African and Africanized Honey bees. eds. G. R. Needham, R. E. Page, Jr., M. D. Baker and C. E. Bowman, Ellis Horwood limited, West Sussex, England.
Issued in furtherance of cooperasfs’e C ~ tension wo.’k acts of May C and June 301914. in cooperation with the U.S. Department of Agr.eulsureo Roy 5. t~auschkolt~ Director. cooperatis,e Extension, college of Agriculture. The Uni’.’ersitv of Arizona.
The Unicersity of Arirora college of Ag,iculture is a,, Couct opportunity employer authorited 10 provide research educat,onal information and other s~rx,c~s On,. to Ifloniduals and institutiOns that tunctiOn without regard to sex race, relig,on color. national origin, age, Vietnam Era Veteran’s status or handicappIng condition.