Bee Health Checker (UK) – Symptoms, Likely Causes and What to Do
When something looks “off” in a hive, it helps to start with what you can see: brood pattern, cappings, bee behaviour, and what’s on the floor and frames. This guide is designed as a practical, UK-style symptoms → likely cause → action checker. It works best as a first-stop page that helps you move from “I’m worried” to “what exactly should I read next?”. If you want a more guided route, use the interactive colony health triage tool. If the main issue seems to be brood quality or odd cappings, compare what you are seeing with the brood pattern guide.
Log an inspection in Members Area Medicine Records (UK)
Quick navigation
- How to use this checker
- Red flags (act immediately)
- Symptoms → causes → actions table
- Notes on terms (CCD, Ascosphaera apis, bee louse)
- Download printable checker
- Next steps
How to use this checker
- Start with the most obvious symptom (e.g. perforated cappings, mummified larvae, crawling bees).
- Match it to the closest row in the table and read the likely causes.
- Use the links provided to decide what to read next — for example the brood pattern guide, varroa overview or the main bee diseases guide.
- Take the safest action first: isolate, reduce stress, verify, record.
- If you can’t confirm, treat it as “unknown” and use the colony health triage tool before doing anything irreversible.
Red flags (act immediately)
- Ropy larval remains, sunken/perforated cappings and a strong foul smell (possible AFB).
- Widespread “melted” larvae with an uneven brood pattern (possible EFB).
- Unusual larvae/pupae breakdown you can’t confidently explain.
In these cases, do not move frames or equipment off site, and avoid robbing. Record what you saw, take photos, and contact an inspector / BeeBase guidance route.
Symptoms → likely causes → recommended actions
Use this table as a practical guide. Many issues overlap (e.g. varroa + virus + stress), so more than one row may apply. Your inspection notes matter as much as the symptom itself. If you are unsure where to start, the colony health triage tool can help narrow things down first. If your concern began during a routine inspection, it is also worth reviewing inspection and hive management so you can compare what you found against a normal inspection routine.
| Observed symptoms | Likely cause(s) | Recommended action (safe first steps) |
|---|---|---|
| Sunken / greasy cappings, perforations, foul smell; larval remains can look “ropy” | American Foulbrood (AFB) (notifiable) | Stop inspection early. Isolate hive. Do not swap frames. Photograph and seek official confirmation. Avoid moving bees/equipment between apiaries. |
| Patchy brood pattern; larvae twisted or “melted”, often before capping | European Foulbrood (EFB) (often notifiable/managed via inspectors) | Reduce stress: ensure food, avoid over-manipulation. Record, photograph, seek advice/inspection. Review hygiene and comb age. |
| White/grey mummified larvae (“chalk mummies”) in cells or on floor | Chalkbrood (caused by Ascosphaera apis) | Improve ventilation and dryness. Replace badly affected comb. Avoid chilling brood. Consider requeening if repeated year-on-year. |
| Hard, dark “stone-like” dead brood; mummified and tough | Stonebrood (Aspergillus spp.) | Improve hygiene and hive conditions (dry, well-sited). Remove affected material where practical. Strong colonies often recover once conditions improve. |
| Deformed/crumpled wings; poor flyers; brood looks stressed; colony dwindles late summer/autumn | Varroa + virus association (esp. Deformed Wing Virus) | Check mite levels promptly. Apply an appropriate treatment for the season. Review IPM plan (monitoring, brood breaks, treatment timing). Then read the quick varroa overview and follow up with your broader varroa pages if needed. |
| Bees trembling/shaking, crawling, unable to fly; sudden adult losses | Acute Bee Paralysis Virus (ABPV), Israeli Acute Paralysis Virus (IAPV) (often linked with varroa pressure) | Treat varroa if levels are high. Reduce stress, ensure nutrition. Avoid combining colonies unless you’re confident you’re not spreading a virus problem. |
| Hairless, shiny black bees; trembling; piles of crawling bees at entrance | Chronic Bee Paralysis Virus (CBPV) | Reduce overcrowding and stress. Improve ventilation and feeding if needed. Replace old comb where practical. Keep notes—patterns over time help. |
| Brood dies in sealed cells; queen cells darkened/blackened | Black Queen Cell Virus (BQCV) (can be associated with stress / Nosema) | Focus on colony strength: good nutrition, reduce stressors, manage varroa. Consider requeening if queen performance is affected. |
| Larvae look like a “sac” with fluid; head often raised; larvae turn yellow-brown | Sacbrood virus | Support the colony: feeding, reduce stress, avoid chilling brood. Replace old comb if heavily affected; requeen if persistent. |
| Dysentery staining on hive front/frames; crawling bees; reduced spring build-up | Nosema (N. apis / N. ceranae) | Improve ventilation, reduce damp, check food, replace old comb where possible. Record and monitor—confirm before using any medication route. |
| Weak colony + comb damage: tunnels, webbing, frass; frames collapse when handled | Wax moth (usually consequence of weak colony / poor storage) | Reduce unused space; strengthen colony; remove badly damaged comb. Store comb correctly between seasons. |
| Unusual beetles/larvae; “slimed” comb; fermenting smell; rapid comb damage | Small Hive Beetle (high concern; not established in UK in most contexts) | Treat as suspect and report promptly through official channels. Do not move bees/equipment until guidance received. |
| Small reddish-brown “mini-lobster” insects on adult bees; irritation but usually mild | Braula coeca (bee louse) | Confirm identification first (rarely serious). Record presence and monitor. Focus on general colony health; avoid unnecessary chemical use. |
| Fast brood decline, deformed brood, poor development; suspected exotic mite issue | Tropilaelaps mite (notifiable/high concern if suspected) | Treat as suspect and report promptly. Stop movements of bees/equipment. Follow official guidance. |
| Sudden “empty hive” feeling with queen present; food sometimes left; no single clear culprit | Colony loss / multi-factor decline (often varroa, viruses, starvation, stress, weather, management factors) | Review the timeline: varroa monitoring + treatments, forage gaps, feeding, queen status, wasp pressure, disease signs. Record lessons learned and adjust the plan. |
Download (printable)
If you’d like a version you can keep in your toolbox or take to the apiary, you can download the Bee Health Checker as a printable checklist.
View on Downloads page Download PDF Download Word
What to read next
This page is designed to help you choose the most useful next guide, depending on what worried you during the inspection.
- I’m still not sure what category this falls into: Colony Health Triage Tool
- I want the main overview first: Bee diseases and pests guide
- The brood looks patchy, uneven or suspicious: Brood pattern guide
- I think varroa may be involved: Quick varroa overview
- I want to compare this against a normal inspection routine: Inspection and hive management
- I think this may be foulbrood or another brood disease: Bacterial diseases (AFB/EFB)
- I think this is more likely virus-related: Viral diseases (DWV, paralysis viruses, etc.)
- I need treatment record guidance too: Veterinary medicine records
Think of this page as a gateway rather than a final answer. Its job is to help you move from symptom spotting to the most relevant next guide, whether that is the colony health triage tool, the main bee diseases and pests guide, the brood pattern guide, the quick varroa overview, or the inspection and hive management page.