Since I wrote the post “The Great Extractor Debate,” several beekeepers have reminded me that a borrowed extractor can be a source of disease. They are absolutely right.
American foulbrood is the disease most commonly associated with used equipment. The disease is caused by the bacterium, Paenibacillus larvae, which is passed from hive to hive as a spore.
Once a spore enters a hive, it is eaten by a young larva along with its food of nectar, honey, and pollen. Inside the midgut of the larva, the spore germinates and the bacterium uses the larva as its own food. After the larval cell is capped by the worker bees, the bacterium produces many spores before it dies. Some estimates put the number of spores produced per larva at 2.5 billion.
When the worker bees attempt to remove the dead larva and clean out the cell, they end up spreading the spores throughout the hive, including the honey supers. Robbing bees and drifting bees carry the spores to other hives, and beekeepers may spread the spores with their hands and tools.
Clean shared extractors carefully
The spores are extremely resistant to heat, dryness, and many chemicals, so a used extractor that is not thoroughly cleaned can easily spread spores to the next beekeeper. This, in itself, is not a danger to humans because the pathogen has no effect on humans. However, should a beekeeper feed any of his contaminated honey to his bees, he can introduce the disease into a once-healthy apiary.
A used extractor—or any other tool—has to be more than visually clean because the spores are so small and well-protected. The recommended treatment is removal of all debris followed by soaking in a solution of household bleach and water.
The cleaning is important because unless the bleach is in direct contact with the spores, it won’t kill them. For this reason, bleach will not work on infected wooden products because the spores may be well-protected between the wood fibers.
Also, if you use a stronger bleach solution, less soaking time is required. But a stronger solution is harder on the equipment, especially the metal parts, of which there are many in an extractor.
It is all a balancing act. In short, if you share an extractor, the best protocol is to keep your honey for human use and do not feed any of it to bees.