Fungal Disease

1 . What is Chalkbrood?

A fungal disease caused by Ascosphaera apis. Larvae become infected after ingesting spores and eventually die, forming hard, chalk-like “mummies.” Usually not an issue for beekeepers in the South because warm temperatures during winter and spring allow the bees to break from the cluster and remove excess moisture collected inside.

2 . What conditions favor chalkbrood?

Cool, damp conditions especially at the edges of the brood nest where temperatures may drop below optimal (~95°F).

3 . How is chalkbrood managed?

• Improve ventilation

• Reduce moisture

• Replace old comb

• Requeen with resistant stock

4 . How can chalkbrood be distinguished from other brood diseases?

The presence of hard, chalky mummies in cells or at the hive entrance is diagnostic.

5 . Key Takeaways?

Chalkbrood is primarily a stress-related disease. Good colony management, especially maintaining healthy, well-ventilated colonies, usually keeps it under control without the need for chemical treatment.