$8 Million Africanized Honey Bee Barrier Proposed

ABJ – November, 1986

For the barrier to succeed $100,000 will be needed immediately to start a pilot project in Chiapas, Mexico.

The Animal and Plant Health Inspection Service (APHIS), has recommended an $8 million plan to stop the Africanized Honey Bee (AHB) in Chiapas, Mexico. A meeting of scientists, apiary inspectors and APHIS personnel took place September 23 in Hyattsville, MD to discuss the merits of the plan as outlined below. If the plan is feasible, then APHIS will be seeking the additional funds to carry out the project as soon as possible. The AHB is now in Guatemala and may soon cross over the border into Mexico if this hasn’t already occurred. Beckeepers who believe the plan will work are urged to contact their congressmen to urge support of the plan monetarily. Experts believe that the AHB will reach the site of the planned barrier within 18 months.

During the meeting total man-power and equipment expenditures were briefly outlined to give those attending an idea of what the proposed $8 million would be used for. There would be a total of 88 stations located along the barrier zone. Each station would contain 44 apiaries of 4-20 colonies spaced at 3 kilometer distances. Also, each station would have 177 drone traps spaced 1.5 kilometers apart. Approximately 1600 bait stations would he established. Each unit would need a supervisor, identifier, control workers, 2-3 vehicles and a control worksite to perform identification work. Each worker would be required to: Check 4.3 apiaries per month; 17.3 drone traps periodically every day and 156.4 bait stations every two weeks. Total figures for the project are: 3,872 apiaries; 38,700 colonies; 15,500 drone traps; 141,000 bait stations and hives; 1,114 unskilled employees; 220 vehicles; 88 remote work sites and 1 central headquarters. Additional activities of the group would include: Swarm trapping; requeening and equipment moderization; trapping AHB drones and intensive production of European drones at queen production sites; establishing an ARS research laboratory in Yucatan and establishing a Mexican research laboratory in Chiapas.

Long-term genetic solutions include ideas such as introducing an east African strain of honey bee known Apis mellifera monticola which never has interbred with the Apis mellifera andansonii.

For the barrier to succeed $100,000 will be needed immediately to start a pilot project. Genetic control is at least 5 years away if the project is started now. APHIS officials realize that the barrier is not a solution in itself, but it may buy time so that needed research can be completed to provide a long-term genetic solution. The barrier will have to be considered a combination Mexican-American project, even though the Mexicans will not provide any of the funds. For the Mexicans the problem will be immediate and so they will have to concentrate on providing health and public safety solutions with control or elimination being a second priority. Congress and the American people must be made to understand that the Africanized Honey Bee problem probably will not be only a southern states concern, but may very well encompass the rest of the United States and Canada. More recent research indicates the AHB has a far greater tolerance for cold climates than originally thought.

Our thanks are extended to Eugene Killion, supervisor of the Illinois apiary Inspection Service, for providing notes for this article.


A team of ARS research leaders was called together in Beltsville, MD on March 17, 1986 by Dr. J. E. Wright, NPS. The purpose of the meeting was to review ARS research leading to the development of a barrier against Africanized bees (AB). The term “barrier” as used by the group refers to a Bee Regulated Zone (BRZ) with appropriate actions that ultimately could prevent the spread of Africanized bees.

It is expected that the AB will be arriving in Mexico in 1986 or 1987 and in the U.S. perhaps as early as 1989 or 1990. The impact of the AB on
agriculture and public safety has been well-documented. This report is intended to present APHIS with strategies that could be implemented immediately in Mexico. Although there can be no a priori guarantee that AB can be stopped, the team agreed that an AB regulated zone should be established in Mexico. It is the recommendation of this team that this barrier be established immediately in the state of Chiapas, Mexico.


1. Identification of Africanized Bees for Survey and Detection.
Two methods are presently being utilized for the identification of AB based on morphometrics. They are a laboratory procedure requiring 26 separate measurements and a field procedure using comb measurements and FABIS (forewing and weight measurements). FABIS is quick and simple and correctly identifies the large majority of European and AB samples.

2. Drone Trapping
An artificial queen pheromone source is placed in a cone-shaped net nine or ten meters above the underlying vegetation. The queen pheromone attracts large numbers of drones into such traps in Africanized areas. Drone trapping has greatly reduced the reproductive potential of AB.

3. Drone Flooding
Colonies prepared specifically to rear large numbers of European drones were shown to effectively increase the mating of European queens with European drones in an Africanized area. The normal production of drones by all managed colonies can be significantly increased by the introduction of frames of drone foundation.

4. Bait Hives
Bait hives, having the scent of recently occupied nests, low internal temperatures (use of insulation and shade), and at least 40 liters of internal volume have had excellent success in attracting swarms. The efficacy of these bait hives are enhanced by the high swarming rate of AB especially during the swarming season when such swarms are thought to travel short distances.

5. Bait Stations
Bait stations combining an attractant and food source can be used to attract foragers from colonies in the surrounding area for sampling bees. If AB are collected, bait stations could be used in conjunction with short-lived insecticides or chitin inhibitors to destroy feral colonies especially during dearth periods.

6. Human Resources
Some person or office can be designated in each local area to monitor and receive reports of swarms. Project personnel would collect samples for identification, destroy the swarm and pay a bounty.

7. Quarantine
A quarantine can prevent the movement and managed colonies out of Africanized areas. Additional vigilance would be necessary to locate and destroy swarms “hitchhiking” on vehicles and to prevent deliberate transport of honey bees from the BRZ.

8. Chemicals
Several chemicals that have been studied have a potential to support the barrier technology. Carbaryl and ResmethrinR are both registered by the EPA for killing honey bees. Since both materials have residual toxicity they should not be used for bees on hive equipment.


1. Identification Methods
A number of researchers and laboratories are pursuing improvement of existing techniques and the development of alternative methods for identification of AB. Classical morphometrics, cuticular hydrocarbons, nuclear and mitochondrial DNA, hemolymph proteins, antennal sensillae, isozymes, venom components and alarm pheromone components are all subjects of ongoing work.

2. Drone Trapping
Drone trap design improvement for traps that automatically kill drones and do not require individual attention are being developed. Additionally, studies are being conducted on trap placement with regard to spacing and height as well as optimum concentration and delivery system for the pheromone.

3. Drone Flooding
Current research on drone flooding is being focused on developing guidelines for queen producers to allow successful matings with desirable drones in Africanized areas. This includes studies on the number of drones required, placement of drone source colonies, mating flight patterns and the drone production potential of feral colonies.

4. Bait Hives
Basic research on bait hives can be considered completed. However, opportunities exist for improvement in design and placement as well as methods to minimize the maintenance of bait hives.

5. Bait Stations
Functional bait stations have been developed that readily attract foragers. Assessment of the distance such stations are effective and recommendations for their dispersal in a sampling grid are underway.

6. Control of Parasitizing Queens
A central characteristic of the Africanization process is the parasitism of functionally or pheromonally queenless colonies by Africanized queens accompanied by tiny swarms. By determining how African queens are attracted to such colonies and developing queen traps, it would be possible to reduce this parasitism.

7. Drone Congregation Areas
The easy identification of leks (drone congregation areas), would facilitate drone trapping and drone flooding techniques. Approaches to finding congregation areas with energy sources of various types such as radar are underway.

8. Behavioral Modification by Genetics
Estimates of heritability and both phenotypic and genotypic correlations among characteristics have been calculated for a wide variety of traits including differences in honey production, defensive behavior, population dynamics, reproductive parasitism, etc. Selection for the important characteristics of defensive behavior and honey production confirms the long-term usefulness of this approach.

9. Behavioral Modification by Management
Management procedures to solve several problems caused by AB are in various stages of completion. Techniques to improve honey production using supplemental feeding and appropriate behavioral stimulation have been developed. Excessive swarming of AB has been shown to be controllable as well as a possible reduction of defensive behavior by alarm pheromone habitation.


1. Drone Trapping
(Refer to C.2 and C.7)

2. Drone Flooding
(Refer to C.3)

3a.* Bait Hives
(Refer to C.4)

3b.* Inter- and Intra-Specific Competition
The potential exists for employing other species of Apis or subspecies of A. mellifera to out compete AB either genetically or behaviorally (e.g. competition for resources or via mating advantage). The most promising candidate identified thus far is the subspecies A. m. monticola which needs to be studied as indicated here.

1) Conduct surveys to gather base line biological data on A. m. monticola in Africa (1986).

2) In Africa, conduct phenotypic response studies following reciprocal translocation with A. m. scutellata and A. rn. monticola. In addition, conduct surveys on the diseases and parasites of A. m. monticola (1986-1987).

3) Export selected phenotypes to West Germany for propagation and further stock evaluation (1987-1988).

4) Conduct island experiments in the New World for intraspecific competition studies (1988-1989)

5) Introduce A. m. monticola in Mexico either in front of and/or behind the BRZ (1989-1990).

3c.* Africanized Bee Identification

Methods for identifying Africanized drones and queens should be developed. (Refer also to C.1)

4a.** Diseases and Parasites

Diseases and parasites may he useful in the destruction of AB in bait hives or extant in the BRZ. Diseases may be venereal (eg. render the queen sterile) and spread by drones infected in special hives, placed in baited hives and lethal to adult bees, pupae, larvae or eggs, or applied as biological insecticides in the regulated zone. Similarly, parasites, for example Mellitobia acasta, known to infest queen pupae should be evaluated.

4b.** Bait Stations

Factors influencing the efficacy of feeding stations should be evaluated. These stations would be charged with a chemical, disease or parasite that could be carried back to the hive where it would weaken, reduce the reproductive capacity or kill AB swarms. (Refer also to C.4)

5. Queen Replacement
Improved methods to mark, locate and replace queens must be developed. One of the barrier strategies is replacement of queens in colonies that have become Africanized.


Surplus forage Jan
samples from Net or
- - ± + + + ± - - - - -

Bait stations

+ + ± - - - ± + + + + +
+ + + + + + + + + + + +
- ± + + + + - - - - - -
- - + + + + - - - - - -
- + + + + a a a a a a
+ + + + + + + + + + + +
- - + + + + - - - - - -

1 – Schedule based on assumptions of available forage activity.
2 – Leave bait hive in place but monitor once a month.


Although the principle research effort on AB is being made by the ARS Honey Bee Breeding, Genetics, and Physiology Laboratory in Baton Rouge, a number of other ARS and University laboratories are also making contributions to the solution of this problem. This list is by no means intended to be all-inclusive but merely represent the collective input from the team based on their personal knowledge.

ARS Laboratories

Baton Rouge, LA

1) Research on the basic population and individual differences in bee behavior, development and response to pesticides between AB and European bees.
* 3a., 3b., 3c. were judged by the team as equal in priority.
**4a and 4b. were judged by the team us equal in priority.
2) Evaluation and improvement of AB identification methods including morphometrics of F1 workers.
3) Conduct genetic studies to determine modes of inheritance, heritability and phenotypic and gentic correlations.
4) Commercial management studies to maintain European bees in an AB area.
5) Basic studies on estimating and reducing feral AB populations and defining an “acceptable” level of Africanization for commercial beekeeping stocks.

Tucson, AZ

1) Research on identification of AB. Methods being evaluated include possible differences in wingbeat frequency between AB and European bees and also possible differences in release rate of sting pheromones.
2) The use of radar for locating drone congregating areas to increase efficiency of drone trapping.
3) Evaluate the pollination efficiency of AB in Mexico and to modify management methods needed to use AB for pollination.
4) Develop low-cost and low-maintenance bait hives for attracting AB swarms using pheromones.

Madison, WI

1) Maintain a closed population (CP) and evaluate the computer model. The CP is a means for storing honey bee germ plasm and is currently a gene pool for several studies on AB and a source of AB free stock.
2) Develop a computer model for predicting honey and wax production from one to five years in advance to evaluate impact of AB.
3) DNA will be enzymatically digested and the fragments cloned for identification of honey bee gene sequences. Stress proteins will be identified for use in quantifying the effects of stress inducers such as disease, parasites, pesticides and environment. DNA probes will also be developed for identifying AB.
4) Determine the optimal levels (and ranges) of hive temperature, humidity and carbon dioxide for the survival of honey bee colonies. Optimizing these factors will contribute substantially to management objectives for commercial beekeeping with European and AB.

Beltsville, MD

1) Research on developing new methods and improving existing methods for the identification of AB. Specifically studies on the use of cuticular hydrocarbons, mitochondrial DNA, and the use of an image analyzer are being evaluated for the identification of AB.
2) Studies on the use of chitin inhibitors for controlling brood rearing are being conducted. Dosage levels, method of feeding chitin inhibitors and the resultant period of no brood rearing need to be evaluated as well as the subsequent fate of the colony.

Logan, UT

1) Research and development of alternate pollinators to be used as possible replacement if Africanization results in a shortage of honey bee colonies for pollination. Specifically, California relies on honey bee pollination for alfalfa seed production, other pollinators such as Osmia sanrafaelae and Chalicodoma mucorea are being evaluated for this purpose.

Non-USDA Research on Africanized Bees

University of California, Berkeley
(Dr. H. Daley)

1) Improving morphometric methods for identification of AB workers.
2) Developing a morphometric method for identification of AB drones.

University of California, Berkeley
(Dr. G. Hall)

1) Research on the use of DNA probes for the identification of AB.

University of Georgia, Athens
(Dr. A. Dietz)

1) Study on distribution of AB in Argentina completed. Manuscripts in preparation.
2) Proposal submitted for short-term project in Kenya on the feasibility of using A. m. monticola as a biological barrier against A. m. scutellata.

University of Minnesota, St. Paul
(Dr. B. Furgala)

1) Development of hemolymph protein analysis system for identification of AB.

University of Kansas, Lawrence
(Dr. 0. R. Taylor)

1) Selection of two bee stocks selected for the time which drone mating flights occur, one for early and the other for late flights.
2) Environmental tolerance (elevation) of AB in Costa Rica.

Smithsonian Institute, Washington, DC
(Dr. D. Roubik)

1) Impact of AB on native pollinators in Panama.


No single approach to an Africanized bee barrier zone has much chance of success. Rather, it is necessary to use a series of actions, each appropriate to a portion of the annual cycle of changing honey bee activities and to one or more of several biological processes leading to Africanization.

The following actions collectively provide tools for an integrated system having a high likelihood of both preventing Africanization in the BRZ and of preventing Africanized bees from passing through the zone. These actions are based on the following known processes of Africanization:

a) human assisted movement
b) prime swarms
c) queen parasitism of established colonies
d) drone parasitism of established colonies
e) absconding swarms
f) mating superiority founded in a numerically greater production of reproductives

1) Establish a Bee Regulated Zone and Institute a Quarantine

In order to institute actions in a barrier zone, a bee regulated zone will have to be designated to control bees and beekeeping. This must include locating and registering all managed colonies. The BRZ must be wide enough so that an Africanized swarm would not likely cross this area undetected. Since absconding swarms are likely to travel many miles, a zone 1660 kilometers wide and extending from coast to coast across the narrowest part of Mexico will be required. A quarantine on the Africanized side of the zone will be necessary to prevent human assisted movement of Africanized bees in or out of the regulated zone. (Relates to Africanization processes a, b, c, d, e, f).

2. Organize a Project Team

A team structured according to classic regulatory project protocols is fundamental to the development and maintenance of a barrier zone. In addition to organizing and conducting routine project activities and activities identified in other sections of this document, the team must have additional special duties. These special duties involve interacting with the general public in the zone and teaching members of the local apiculture community management of bees to conform to project needs. Also, the team will institute a bounty system to encourage the reporting of swarms and feral colonies. Upon receiving of a report, the team will verify the existence of the reported bees, sample them, and pay the bounty. The bounty must be kept low enough to discourage people from rearing or stealing bees in an attempt to defraud the program. (Relates to Africanization processes a, b, and e).

3. Retain Beekeeping

It will be vital to the success of the project to retain beekeeping in the regulated zone for social as well as biological reasons. These managed colonies will provide a reservoir of desirable drones that will impact the feral population. All rustic hives will have to be replaced by modern movable-frame equipment so that drone production and queen certification can be faciliated. Beekeepers must be supplied with drone foundation prior to seasonal colony buildup. They must be instructed in the placement and quantity of drone comb desired. The colonies must be maintained with European queens so that European drones are produced (see also F.7). The tendency of Africanized drones to migrate to European colonies (drone parasitism) will have an important effect on desirable drone production. Steps must be taken to limit the entry of Africanized drones into managed colonies. Registration of all managed colonies in the regulated area will facilitate this endeavor. (Relates to Africaitization processes a, d and f).

4. Establish Drone Traps

Within the regulated zone, establish “state-of-the-art” drone traps with pheromone lures on a 1.5 km grid. These dimensions can be adjusted as more information is gained on drone flight patterns in the area including the location of leks (drone congregation areas). (Relates to Africanization processes d and f).

5. Drone Flooding

The trapping of Africanized drones in an area (F.4) must be alternated with the release of desirable drones (F.3). A schedule of several days of trapping all free-flying drones, while desirable drones are confined to colonies, followed by several days with no trapping and free flight allowed from European colonies, must be established. This schedule could be rotated over 2-3 small regions, utilizing the same traps and personnel in all regions. Trapping needs to be done only during periods of significant local drone production. (Relates to Africanization processes d and f).

6. Establish Bait Hives

One way to reduce the spread of Africanized bees across the barrier zone is to establish bait hives to collect and destroy Africanized swarms. Where access is available, the hives should be closely spaced, especially on the Africanized bee side of the barrier, five hives per square kilometer is recommended. However, in parts of the zone having restricted aceess, many of these hives will he restricted to roadside placement. In this case, ten evenly spaced hives per linear kilometer is recommended. Until bait hives are developed that will kill swarms automatically, these hives will need to be inspected biweekly during the swarming season. (Relates to Africanization process b and e).

7. Certify Colonies

Honey bee queens frequently live only a few months in the tropics. Also, Africanized queens often replace European queens in European colonies. Therefore, at approximately 4-month intervals, all managed colonies must he inspected for possible Africanization and recertified. This certification could be facilitated by the exclusive use of marked European queens. (Relates to Africanization processes a and c).

8. Collect Composite Samples

During the season of nectar availability, it is important to survey for the presence of new AB arrivals in the regulated zone. Monthly composite samples of foraging workers collected on flowers at 0.5 km grid intervals will supply information on their presence. When samples containing AB are found, bee-lining and other techniques can be used to find the source of Africanized foragers so that it can be destroyed. (Relates to Africanization processes a, b, c, e).

9. Inspect Ships
All ships leaving ports in Africanized areas must be inspected immediately upon arrival in ports within or beyond the regulated area. In addition, ships docking in the Yucatan, a probable heavily infested area, will be inspected just prior to departure. Visual inspection could be aided by new technology such as detection of swarms by directional antennae (sound). Also, if bees will fly while on a ship underway, feeding stations can be used to discover and destroy “hitchhiking” swarms. (Related to Africanization processes a, b, e.)

10. Trap Queens

In each apiary one colony should be maintained as an attractant for Africanized queens. To achieve attractiveness, the queen in this colony will be caged, simulating queenlessness. Because the queen is caged, the colony must receive frequent additions of brood or adult worker bees. The hive should be fitted with a trap to collect parasitizing Africanized queens. (Relates to Africanized process c)

11. Survey Using Bait Stations

During dearth periods, when foraging is possible (no rain), bait stations should be set up to survey bee populations. Individual foragers will be collected at such stations and identified. This system will be used alternatively with roadside sampling (F.8), which is dependent on natural flora. (Relates to Africanized processes a, b, c, e.)