Diseases and Pests

American foulbrood is a destructive disease affecting honeybees in North America. Your hives need to be monitored for this disease at all times. This diease spreads when larvae becomes infected by ingesting spores from their food. The larvae will eventually die from the disease.

How America Foulbrood Spreads

American foulbrood is highly contagious and easy to spread within a hive and subsequently the apiary. The disease can rapidly spread throughout an infected hive because the nectar stored in infected cells will also become contaminated. As the nectar is moved, each cell that comes into contact with it becomes contaminated. It can be spread to other hives from drifting bees, robbing, or even sharing contaminated bee equipment. If a contaminated hive or equipment is moved to a healthy yard, it can also contaminate the healthy yard as well. This might occur before the beekeeper is even aware of an AFB issue.

Symptoms

American foulbrood symptoms include:

• A spotty brood patch
• The cappings of the sealed brood may have holes in it and appear dark and sunken
• Brown ‘coffee coloured’ larvae inside the cells

Overall, it’s easy to see the difference between healthy brood and AFB diseased hives but testing must be done to confirm.

Treatment

Treating American foulbrood has been done but isn’t practical at this time. The best way is to destroy (burn) the bees and all equipment that have come into contact with the disease. It is possible to wax dip your equipment to kill the AFB spores and some beekeepers routinely wax dip their equipment as a precaution.

Prevention

In Manitoba, a preventative treatment of Oxytetracycline can be applied in spring or fall. In spring, it must be done at least 4 weeks before the start of honey production. Treatment is done by spreading the treatment across the outside part of the frames. Overwintered colonies should receive 2 tablespoons of oxytetracycline/icing sugar mixture per colony per application. Three applications are required 4-5 days apart. Spring packages receive 1 tablespoon per application and also receive 3 applications 4-5 days apart.

Final Thoughts

We have been very fortunate and have never had a single case of this disease in our Apiaries. Using precautions can help protect against this disease and prevent large losses from occurring.

If you are purchasing used beekeeping equipment, you should check if AFB issues have ever been a concern in the apiary. It would be worthwhile considering purchasing used equipment with recent exposure.

What is Chalkbrood?

Chalkbrood is a disease caused by a fungus (Ascosphaera apis) that affects in honeybee brood. It is usually seen in spring when the weather is still cold. There can be several reasons for bees to become infected but I feel that stress on a hive is one of the main reasons we’ve seen. Chalkbrood will usually not kill a hive, but it will severely reduce hive population causing a major reduction in honey production. If it’s seen, the beekeeper needs to take appropriate action.

What to look for:

• Whiteish coloured brood that looks like chalk inside the brood patch.
• You may first see these white ‘mummies’ lying around the entrance of a hive as bees have carried out the infected brood.

Where does it come from:

• It’s often seen in spring in overwintered hives. Caused by stresses on the hive.
• Cool temperatures
• Weak Colonies
• Poor ventilation

How can it be prevented:

• Using stock that is resistant.
• Increase ventilation of the hive.
• Keep switching out old frames for new drawn out frames.
• Making sure your hives have proper nutrition.
• Spoil your bees using essential oils stimulants (We’re serious)

If you find a hive where chalkbrood is an issue, we will usually requeen and give more brood to the hive if it’s a serious problem. However, if you hive is too weak you may be best to cut your losses and move on.

We’ve had years where it has been a problem for several hives and we’ve had years where it’s been no issue at all. Some years are so good, you’ll even forget about it until someone asks about it.