Control and Eradication of American Foulbrood Disease in Hives and Honey Bee Colonies
Note Number: AG1454
Published: September 2012
Control of American foulbrood (AFB), an infectious and notifiable honey bee brood disease is achieved by the destruction of honey bee colonies, and destruction or sterilisation of hive components. This Information Note provides information to help beekeepers control and eradicate AFB in their apiaries.
This note provides information on control and eradication of AFB. Beekeepers who wish to confirm if a brood disease is present in bees should read Information Note AG0990 A Guide to the Field Diagnosis of Honey Bee Brood Diseases, Information Note AG1426 Diagnosis of American foulbrood disease of honey bee brood and Information Note AG1249 Samples for Laboratory Diagnosis of Bee Diseases.
Notification of presence of AFB
The Livestock Disease Control Act 1994 requires that anyone who knows or suspects that AFB is present in his or her apiary must notify a DEPI apiary officer (contact details below) or the Director, Animal Biosecurity & Welfare within 12 hours by calling (03) 5430 4525 (24 hours a day) or faxing (03) 5430 4520.
Failure to notify is to break the law.
AFB and spores
AFB is a bacterial disease which produces spores too small to be seen by the naked eye. AFB spores remain viable for decades, perhaps up to fifty years or more. As well as being present in the remains of infected honey bee larvae and pupae, spores will occur in honey and pollen, and on the surfaces of combs, frames and all other components of infected hives. The transfer of any of these items to healthy hives will result in spread of the disease.
The proven way of controlling an outbreak of AFB is to destroy the infected hive and bees. Sound hive components worth saving can be sterilised (as described later) to make them disease free and safe for reuse in the apiary.
Hives in which bee colonies have died and hives with reduced adult bee populations that are unable to prevent robber bees from entering should be completely closed. This includes closing the entrance and any other holes that may allow robber bees to gain entry. Robbing of honey is a major cause of disease spread. Hives that have been closed should be moved to a shaded area away from direct sunlight to prevent meltdown of combs and leakage of honey from the hive.
Extracting honey from AFB infected hives
There is a major risk of spreading AFB if honey is removed and extracted from infected hives. Beekeepers who wish to extract AFB infected honey should discuss this with a DEPI apiary officer. If honey is to be removed from AFB infected hives for extraction, it must be done before the bees are killed with petrol as described below. It is important that all containers holding this honey are labelled with the words "AFB honey". This will enable the honey packer to direct the product to markets that do not require certification that the honey has been produced in apiaries free of AFB.
Preparation before destruction of items by burning
Enquire at your local government council for information on local laws and whether a permit is required to burn hives in the open.
The Department of Sustainability and Environment (DSE) is responsible for management of fires on public land. Where hives are on public land apiary sites, contact the local DSE office to determine if a fire to burn hives will be permitted. Private land that lies within 1.5 km of public land (for example, parks and forests) may be within a Fire Protected Area. The local DSE office can advise if a fire is permitted on private land in a Fire Protected Area.
Application to burn hives during the declared Fire Danger Period should be made at the local municipal office. The Fire Danger Period is declared by the Country Fire Authority when the risk of bushfire is high and the start and end of the period will vary across Victoria. The Fire Danger Period excludes National parks, State forests and other protected public land. If the hives to be destroyed are in a Fire Protected Area on private land, you must obtain a permit from your local DSE office.
When a permit to burn cannot be granted during a declared Fire Danger Period, the bees should be first killed using unleaded petrol as described in the next paragraph. The hives infected with AFB can then be bagged using strong plastic bags to make them totally bee-proof. It is wise to consider double bagging infected hives. They should be then placed in a protected area in a shed, away from sunlight and livestock until a permit can be granted.
Always observe fire restrictions including days of Total Fire Ban.
Permit for unleaded petrol
Unleaded petrol is used to kill bee colonies prior to burning hives. The Australian Pesticides and Veterinary Medicines Authority (APVMA) has issued a Minor Use Permit which enables Victorian beekeepers to legally use unleaded petrol for this purpose provided the beekeeper has read the permit or has had the words of the permit read to him/her.
The title and number of the permit are: Permit to allow minor use of an agvet chemical product for the control of abandoned or diseased European honeybee hives: Permit Number – PER12843. The permit may be downloaded from the APVMA website at: http://permits.apvma.gov.au/PER12843.PDF
The permit includes the following points:
- petrol must be used and handled in accordance with the Material Safety Data Sheet which forms part of the permit.
- all frames (and combs) exposed to petrol MUST be burnt and buried following treatment.
- caution should be taken when frames (and combs) exposed to petrol are then exposed to flame.
- beeswax and honey exposed to petrol must not be provided for human or animal consumption.
Preparation of a pit for burning hive material
Burn the diseased combs and hive components in a pit, large enough to accommodate all items and deep enough to retain any melted wax and honey (Photo 1). Honey and wax that flows out of the pit may be gathered by robber bees and be a source of infection to healthy colonies. A pit that is deeper at one end than the other allows liquid honey to accumulate away from the seat of the fire and avoids smothering the fire.
The pit should not be dug in low lying areas where storm water may wash soil away and expose any unburnt items that might cause a disease risk to nearby bees.
Sufficient dry wood should be on hand to enable a hot fire to be burning before combs of honey are placed on the fire. This is not necessary when there is little honey present as the combs and wax on hive components will usually generate enough heat to burn the honey.
Killing the diseased honey bee colonies
The APVMA permit stipulates that unleaded petrol should be applied at a rate of 125 - 250 mL petrol per hive. All hive exits should be closed when the bees have stopped flying. Flight usually stops around sunset, but sometimes much earlier at cold temperatures. Apply petrol to a cloth placed under the hive lid or apply petrol directly onto the frames in the top box. It is a good idea to tilt the hive from front to back to avoid loss of petrol through the (closed) hive entrance. It may take 5-15 minutes before all bees are dead.
It is extremely important to remember that a bee smoker in operation has a fire which can ignite petrol.
Salvage of hive components
Store hive components worth sterilising for later reuse so that robber bees cannot gain access to traces of honey. Boxes should be stacked on a bottom board and covered with a hive lid and then fastened using an Emlock or similar fastener. Close the hive entrance and seal any other possible entry points, including missing or broken ventilator grids in the cover with durable tape. Remove any honey present on the outside of these boxes by washing with a wet cloth. Salvaged material must be placed in a bee-proof area until it can be taken for sterilising.
Burning the hives
Use waste wood to start a fire in the pit and continue to add wood so that the fire is well established and hot enough to quickly burn the infected items. Place the hive components including combs of brood and honey on the fire a few at a time so as not to smother the fire. Add metal lids, bottom boards and queen excluders last.
Take care not to spill honey and comb on the ground where they can remain unburnt and available to robber bees.
When the wooden components have burnt, the hole can be backfilled with the excavated soil. At least 30 cm of soil should be placed over the remains of the burn pit.
Actions after the burn
Sterilising hive components by gamma-irradiation
Gamma-irradiation is a safe and effective way of sterilising AFB infected hive components. Steritech Pty Ltd, Dandenong South, operates the only gamma-irradiation plant in Victoria. The company has full details of price, protocols for presenting hives for irradiation and a form Request for irradiation of bee equipment on its website at: http://www.steritech.com.au/sites/default/files/steritech_vic.pdf
It is usual for hives to be left at the plant and collected after irradiation some days later. Beekeepers should carefully determine the economic benefits of having material irradiated in comparison to destruction of the entire hive. The calculation should include cost of travel and preparation of hive material as required by Steritech.
Beekeepers may be eligible to receive compensation if their bees and/or hives are destroyed or sterilised due to AFB. Compensation is not payable to an unregistered beekeeper or to a beekeeper who failed to notify the presence of field signs of AFB in his or her hives to a DEPI apiary officer. It is necessary for a beekeeper to notify an officer of the presence of AFB before infected bees and hive material is destroyed and/or irradiated. The officer will, at this time, advise on how to apply for compensation.
Compensation is paid from the Honey Bee Compensation and Industry Development Fund. The money in the fund is derived from registration fees paid by beekeepers.
Management of the apiary after the initial clean-up of AFB
In many cases, it is an unfortunate fact that after the initial clean-up of AFB infected hives in an apiary, other hives may sooner or later show infection. These occurrences should also be reported to DEPI.
After the initial clean-up, brood in all the remaining hives should be inspected every 6-8 weeks for a period of twelve months to detect any new AFB infection. These inspections are suspended during the cold winter months but they should resume immediately suitable weather occurs in spring.
Brood should also be inspected when taking honey from hives. If AFB is detected in a hive the honey should not be removed and extracted with combs taken from hives which have no symptoms of AFB.
Samples of honey extracted from healthy hives in the apiary can be laboratory tested to determine if AFB spores are present. The detection of spores may indicate that one or more hives may become diseased at a future time. It is important that the sample where possible contains extracted honey from all the hives in the yard (apiary). Full details on procedures for collecting and submitting a honey sample for a honey culture test are found in the Information Note AG1145 Honey culture tests to detect American foulbrood.
The interchange of hive components, including extracted combs, from an infected apiary to any other apiary managed by a beekeeper will result in the spread of AFB. Barrier management is a system that prevents interchange of material. Further information is found in the Rural Industries Research and Development Corporation's publication Honeybee disease barrier management systems at: https://rirdc.infoservices.com.au/items/01-052.
Contact/Services available from DEPI
The following DPI apiary officers are available to provide additional advice:
Rutherglen, Joe Riordan, Telephone (02) 6030 4516, Mobile 0417 348 457.
Bendigo, Daniel Martin, Telephone (03) 5430 4621, Mobile 0428 752 449.
This Agnote was developed by Russell Goodman, Biosecurity Victoria, Knoxfield, Joe Riordan, senior apiary officer, Rutherglen and Daniel Martin apiary officer, Bendigo, in September 2012.