BeezKnees

Bee Health Checker (UK) – Symptoms, Likely Causes and What to Do

UK apiary beehives where routine inspections and health checks take place

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.

Members tip (HiveTag): If you’re using the BeezKnees Members Area, you can log symptoms during an inspection, attach photos, and track “what you did next” over time (treatment, requeen, unite, feed, comb change).
Log an inspection in Members Area Medicine Records (UK)

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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.
  • Take the safest action first: isolate, reduce stress, verify, record.
  • If you can’t confirm, treat it as “unknown” and seek advice before doing anything irreversible.

Red flags (act immediately)

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.

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).
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.
Good record-keeping makes this table far more useful. If you’re a HiveTag member, log: what you saw, what you did, and what changed by the next inspection (photos help).

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.

Free download: Includes confirming checks, severity ratings, and mini callouts for red flags and common UK issues.
View on Downloads page Download PDF Download Word

Next steps (recommended links)

Best workflow: Use this checker first → read the detailed guide → record it in your inspection notes → review at the next inspection.