Barrier systems separate single hives, groups of hives or entire apiaries into separate, distinct units. Once the units have been defined, interchange of bees, honey and hive components between the units is prevented. Beekeeping equipment must be thoroughly cleaned or sterilised between uses in each unit.
Barrier systems were developed as a method of limiting the spread of American foulbrood between hives and apiaries. While they are very effective at reducing the spread of AFB and other diseases, they should never be considered a replacement for regular brood inspections. Barrier systems do not prevent outbreaks of AFB and so brood inspections are still required. Barrier systems do, however, make management of AFB much more efficient.
13.1 A beekeeper should maintain a barrier system that divides the apiary into one or more clearly identified, isolated sub-units and movement of hives, components and appliances between these sub-units should be strictly controlled.
13.2 The barrier system should include the following elements:
(a) Clear, permanent marking and identification of hives, components and appliances within each sub-unit.
Individual hive barrier system
The most effective barrier systems are individual hive barrier systems. In these systems, frames from a particular hive are always returned to the same hive. As a result, supers and combs are kept in single, non-interchangeable units. While this is very effective in limiting the spread of diseases such as AFB between hives, it is also the most logistically difficult and may not be feasible for very large beekeeping operations. However, commercial beekeepers with mobile extracting plants will be able to extract honey at the apiary site and so returning the extracted frames and boxes to the same hives will be much more practical.
Apiary barrier system
In this system, the beekeeper defines each group of hives within their operation as an apiary and then each apiary becomes a separate entity. Materials are then only interchanged within each apiary and not between them. These systems are more practical for large-scale beekeepers. They give beekeepers confidence that if a disease such as AFB is found in one hive, it will not have spread beyond that hive’s apiary group.
Extended apiary barrier systems
Some beekeepers may wish to define the barriers within their operation so that two or more apiaries are included in each group. In this case material may be interchanged within the apiaries in each group, but not between each group. While this may be easier logistically, the effectiveness is much reduced as many more hives are exposed to potentially infected transferred material.
There are many different variations of the above systems. The information below provides some details of different barrier systems and case studies of where they have been successfully implemented. It’s up to each beekeeper to decide which barrier system works best for their operation.
The benefits of implementing a barrier system
As mentioned, barrier systems were developed in large part as a management strategy for AFB. The major benefit of implementing a barrier system is limiting the spread of this disease, which is the most serious honey bee disease currently present in Australia. In particular, the barrier will allow for limiting the spread of the disease while it is in the early stages. Early AFB infections may be difficult to detect but infected hives will still be able to spread the disease. If a barrier system is in place, beekeepers can be confident that even an AFB outbreak that they have not yet detected will not be able to spread beyond the unit in which it has occurred.
Honeybee Disease Barrier Management Systems (Rural Industries Research and Development Corporation)
The barrier management system – a best practice video from the Honey Bee and Pollination Program
American foulbrood – barrier systems (NSW Department of Primary Industries)