So we went through the hives in Randwick as part of the Sydney Bee Club field day, doing our inspections leading up to winter. One of the hives was looking a bit slow despite being re-queened recently and deserved a look. I always tell people to look and listen to your hives before you open them as lots can be learned using your senses. We cracked the hive open, found two full supers of honey and were rubbing our hands together with excitement before we noticed the brood looked a bit off. Closer inspection revealed American Foul Brood. AFB as it’s called is a bacterial spore infection that affects larvae and causes it to die in the cell.
It has a distinctive pattern and can be tested with a rope test (poking a stick into a capped cell and seeing if the mush ropes out). There are plenty of online resources about AFB including this one: http://www.dpi.nsw.gov.au/agriculture/livestock/honey-bees/pests-diseases/videos.
It’s easily spread by contaminated frames and honey. Usually it’s spread by an infected hive that is robbed and the robbing bees take the infected honey back to their hive and the cycle continues. We plan to destroy the hive in the next few days by burning it and will irradiate the supers and frames that may have come into contact with it.