American Foulbrood#
1 . Historically, what is the most damaging disease of honey bees?
American Foulbrood (AFB)
2 . What is the causative organism of AFB?
Spores of the bacterium Paenibacillus larvae larvae
3 . What was the motivation for the establishment of State Bee inspections?
To reduce the spread of AFB
4 . When does Paenibacillus larvae larvae enter the life cycle of the honey bee?
When larvae ingest spores from contaminated food or mouthparts
5 . When does Paenibacillus larvae larvae kill the honeybee?
After the larvae is capped (prepupa or elongated pupa)
6 . What color is dead brood killed by AFB?
Chocolate-brown color.
7 . What is the smell of a hive infected with AFB and dead brood?
Sulfurous smell much like rotten eggs or that of chicken house
8 . What is one characteristic that you can see in brood that dies in the pupal stage from AFB?
Tongue extending toward the cell roof
9 . What is the “ropy test”, how do you perform it and what does it signify?
To perform a ropy test, put a small stick, toothpick or pine needle inside the cell of brood that you think is infected and swirl it around. As you withdraw it, the dead brood will stick to the instrument used and form a stingy rope extending out from the cell.
10 . What happens to the larvae that die from AFB?
The dead larvae becomes a hard brittle scale that will attach to the cell floor. It is almost impossible for the bees and the beekeeper to remove. Each scale may contain billions of spores and are likely to spread to all parts of the hive and then to other hives as well.
11 . What should you do if you detect AFB in one of your colonies?
Contact the State Bee Inspector immediately. If AFB is confirmed, depending on the state of the disease, it may have to be destroyed by burning the entire hive, bees included. If the disease is limited to a frame, a shook swarm may be possible to save the colony. All frames are removed and destroyed along with any of the supers. Bees are “shook” into a completely new hive with fresh frames. The bees are then fed heavily and treated with an antibiotic.
12 . There are two antibiotics licensed in the US for AFB, Terramycin and Tylosin. What are these useful for and how could you use them?
Antibiotics are useful for preventing the spread of AFB, but not for its treatment since antibiotics only kill the vegetative bacteria but not the spores. The spores can only be killed by fire or when treated with ethylene oxide. Otherwise they can remain for years. The antibiotics should not be used with honey supers since the antibiotics will leave residue in the honey. In order to purchase antibiotics to control disease in honey bee colonies, you must obtain a prescription from a veterinarian. Not all veterinarians are trained beekeepers. To find a veterinarian for your honey bees, go to the Honey Bee Veterinary Consortium (HBVC) website to find one in your area.
13 . What are some strategies for preventing the spread of AFB throughout your apiary?
Wash hands and sterilize your hive tool between each colony
Avoid feeding your colonies commercial honey or pollen from unknown sources
Be cautious when buying or using used equipment. New is always safer!
If AFB is present in a hive, burn and dispose of your infected frames and move the hive out of the apiary.
14 . What is a “hygienic queen” and how might she help prevent AFB?
A hygienic queen has been selected for specific traits. Her offspring are able to detect, uncap and remove infected or infested larvae in the brood chamber. These lines are somewhat effective against various disorders, including AFB, chalkbrood, varroa, and small hive beetles (SHB).