Necessary knowledge: Healthy beekeeping is not about treating every unusual sight as a disaster. It is about recognising which observations belong in your notes, which require testing, and which mean you should stop moving bees and call the competent authority.
Start with patterns, not a single symptom
A patchy brood pattern, crawling bees or an unexpectedly weak colony can have several causes. Queen failure, starvation, chilling, pesticides, viruses and infectious brood disease may overlap. Avoid diagnosing a regulated disease from one photograph or one cell.
A practical alert system
Green — routine observation
- Normal seasonal changes in colony size.
- A small amount of dead brood with an otherwise coherent brood pattern.
- Expected drone eviction or winter mortality.
Record the observation, compare it with neighbouring colonies and check again at the next appropriate inspection.
Yellow — investigate soon
- Persistently patchy brood.
- Unexplained failure to gain strength.
- Abnormal numbers of crawling or deformed bees.
- Varroa monitoring results approaching your local intervention threshold.
Review food, queen status, brood appearance and recent treatments. Use an established sampling method and seek an experienced second opinion if the picture remains unclear.
Orange — isolate your decisions
- Multiple colonies with similar unexplained signs.
- Sunken, perforated or discoloured brood cappings.
- Larvae with abnormal colour, consistency or position.
- Rapidly increasing adult mortality.
Do not sell, combine or move colonies, brood combs or used equipment while an infectious cause is plausible. Do not move suspect combs through a shared honey room.
Red — call before acting
- Signs compatible with American foulbrood.
- A beetle, mite or hornet that may be a regulated or invasive species.
- An unusual pest associated with imported bees or equipment.
- An official restriction zone affecting the apiary.
Photograph what you can without spreading material, close the colony, clean obvious contamination from tools and contact the competent bee-health authority. Do not destroy evidence or transport samples unless instructed.
What to record
- Apiary and colony identifier.
- Date, weather and recent colony movements.
- Brood pattern, food stores and queen status.
- Varroa monitoring method and result.
- Treatments, product, batch and date.
- Photographs and which frame they show.
- Purchased bees, queens, combs or equipment.
Sweden
The Swedish Board of Agriculture states that only varroa, American foulbrood and European foulbrood have so far been detected in Sweden among the regulated bee threats it lists. Current restriction zones can change during the season. Swedish beekeepers should check the current official map and contact the responsible bee inspector or county administrative board when required.
Elsewhere
The correct contact varies by country: it may be an apiary inspector, veterinary authority, agriculture department or invasive-species reporting service. What2Know will add country-specific contact cards; until then, use the national animal-health or agriculture authority rather than relying solely on social media diagnosis.
Sources
- Swedish Board of Agriculture: bees, bumble bees and bee inspection
- Current Swedish restrictions for bees and bumble bees
- World Organisation for Animal Health: diseases of bees
Reviewed 16 October 2026. Educational information only. Disease reporting duties and movement rules depend on location; follow the competent authority’s current instructions.