Excerpt:
Foulbrood diseases are some of the most concerning conditions a beekeeper can face. Whether it’s American foulbrood (AFB) or European foulbrood (EFB), these diseases pose serious threats to bee colonies. In this blog, we’ll discuss the differences between AFB and EFB, their symptoms, and, most importantly, how beekeepers can prevent and manage these diseases to ensure the health of their hives.
What is Foulbrood?
Foulbrood is a bacterial disease that affects bee larvae, leading to the destruction of the colony if not managed properly. There are two primary types of foulbrood that beekeepers should be aware of: American Foulbrood (AFB) and European Foulbrood (EFB). Though both are harmful, they have different causes, symptoms, and management strategies.
American Foulbrood (AFB)
Cause:
American foulbrood is caused by the bacterium Paenibacillus larvae, which infects bee larvae. It is highly contagious and can spread quickly between colonies through contaminated equipment or even bees from infected hives.
Symptoms:
- The infected larvae die at various stages of development and become sunken, brown, and eventually black.
- The disease emits a distinct, foul odor (hence the name “foulbrood”).
- The infected brood area may appear uneven, with healthy brood areas beside dead or diseased larvae.
- A characteristic sign of AFB is the “rope test,” where you can pull out the dead larvae with a toothpick or stick and see string-like material stretch as you pull it.
Management:
- Burning: The most effective treatment for American foulbrood is to destroy the infected frames, bees, and combs to prevent the spread of the disease.
- Antibiotics: Some beekeepers use antibiotics like terramycin, although it is increasingly controversial and ineffective in the long run, as it doesn’t eliminate the disease completely.
- Preventative Measures: Regularly inspecting hives for signs of infection, practicing good hive hygiene, and using only clean, disinfected equipment can help prevent AFB outbreaks.
European Foulbrood (EFB)
Cause:
European foulbrood is caused by the bacterium Melissococcus plutonius. Unlike AFB, EFB tends to affect younger larvae and is less contagious. However, it can still weaken a colony, especially if left untreated.
Symptoms:
- Infected larvae are often discolored and may appear twisted or curled.
- The larvae tend to die earlier than in AFB, before they reach the pupal stage.
- The disease typically affects a patch of the brood rather than spreading across the entire hive.
- The odor of European foulbrood is milder compared to AFB, though the infection still presents a risk to the hive’s health.
Management:
- Antibiotics: EFB is often treated with antibiotics, especially oxytetracycline. These treatments can be effective if administered early.
- Isolate Infected Colonies: Isolating the affected colonies is key to limiting the spread of the infection.
- Shaking and Requeening: Some beekeepers remove infected larvae and shake the bees to a clean hive or requeen the colony to help reduce the disease’s spread.
- Good Hive Hygiene: Regular inspections and replacing old combs can help prevent and manage EFB.
Differences Between AFB and EFB
| Aspect | American Foulbrood (AFB) | European Foulbrood (EFB) |
| Bacterium | Paenibacillus larvae | Melissococcus plutonius |
| Infection Progression | Rapid and destructive | Slower and less severe |
| Contagiousness | Highly contagious | Less contagious |
| Symptoms | Sunken, dark larvae with a foul odor, rope test | Discolored larvae with no strong odor, curled larvae |
| Management | Destruction of infected equipment or colonies | Antibiotics, requeening, and hive isolation |
| Treatment | No reliable antibiotic solution; burning is common | Antibiotics are often effective |
How to Protect Your Hive from Foulbrood
Preventing foulbrood requires a combination of careful monitoring, good hygiene, and vigilance. Here are a few key practices to help protect your hives from foulbrood:
- Regular Inspections: Inspect your hives often for signs of disease, especially during the brood-rearing season.
- Maintain Healthy Colonies: Strong colonies are less likely to succumb to diseases. Keep your bees healthy through proper nutrition and pest management.
- Disinfect Equipment: Always clean and disinfect beekeeping tools, hive boxes, and frames between uses.
- Isolate Infected Colonies: If you find signs of foulbrood, isolate the affected colony immediately to prevent the spread of infection.
- Avoid Using Contaminated Equipment: Only use equipment from healthy hives, and never share equipment between hives unless it has been thoroughly cleaned.
Conclusion
Foulbrood diseases, both American and European, present serious challenges to beekeepers. While American foulbrood is more deadly and difficult to manage, European foulbrood can still have a negative impact on your hive’s health. Early detection and intervention are crucial to saving your colony. By staying vigilant and practicing proper hive management, you can reduce the risk of foulbrood and help ensure the long-term health of your bees.
Regular inspections, proper hygiene, and isolation of infected hives will help minimize the impact of these diseases. Always remember, a healthy hive is a happy hive!
