Honey bee killer is still on the increase
From the April 2009 edition of Agriculture Today.
As deadly outbreaks increase, beekeepers need to refocus on the seriousness that the disease American foulbrood poses to their industry.
NSW DPI apiary livestock officer, Nick Annand, said there was a 20-fold increase and rising in the number of outbreaks over four decades in NSW.
The threat of varroa mites entering Australia and the arrival of the small hive beetle had added to the issues beekeepers had to deal with.
“However, American foulbrood needs to be acknowledged as a major problem,” Mr Annand said.
“Lack of awareness, knowledge and recognition of symptoms by some beekeepers is contributing to the increase in AFB outbreaks,” he said, adding that attempts to control the disease with home remedies only leads to further outbreaks, extra costs, labour and lost yields.
“Similarly the use of antibiotics does not eradicate American foulbrood.
“It only masks the symptoms and the disease reappears after the effect of the antibiotic wears off, which can be within six weeks.
“It is illegal to treat a hive with antibiotics that is known to be infected with American foulbrood.”
While NSW DPI has reduced its service inspecting bee hives, placing responsibility for inspection on owners, the Department still educates, regulates, tests samples and provides direction in the control of AFB.
“All beekeepers are responsible for regularly inspecting their own hives, recognising the signs and symptoms of the various bee diseases, including AFB,” Mr Annand said.
“Unfortunately some beekeepers are not as diligent as they should be but infection rates could be drastically reduced if all beekeepers played their part.”
To manage AFB, the brood chamber of the hive should be examined thoroughly at least twice a year (spring and autumn) as well as whenever a hive is doing poorly.
Old equipment should be used with caution, so should second-hand equipment.
According to Mr Annand, transfer of gear between hives and apiaries should be kept to a minimum.
“Once a hive is identified as infected, the colony must be killed and the equipment is either destroyed or gamma irradiated,” he said.
“An infection of AFB and the subsequent clean up is a costly exercise for a beekeeper.”
AFB is a notifiable disease under the Apiaries Act 1985, requiring notification to NSW DPI within 24 hours of discovery.
How it takes hold
American foulbrood disease (AFB) is caused by the bacterium Paenibacillus larvae.
It has been in Australia since early introductions of honey bees.
Only bee larvae less than 24 hours old can become infected when fed food containing bacterial spores, resulting in the death of the larva or pupa after the cell is capped off.
Each individual that dies produces 2.5 billion more P. larvae spores which provides a further source of infection to the hive.
This rapidly increases the spore load in the hive, raising the chance of infection of young larvae.
The spores are very hardy and long lived (more than 50 years).
The increasing numbers of larvae dying from AFB eventually results in the death of the colony.
Contact Nick Annand, Bathurst, (02) 6330 1210, nick.annand@dpi.nsw.gov.au
