Practical Guide (poster): 2 How to recognize diseases
Regular inspection of colonies makes it possible to identify potential health problems at an early stage and to implement planned and targeted measures. It is essential to check and assess colonies at least in spring (when grape hyacinths are in bloom), in summer (between the summer honey harvest and the first summer treatment), and in October (before overwintering).
Official Practical Guide (poster) – Summary
Practical Guide: 01 Recognising diseases / Recognising pests (01/2026)
- Objective: Recognise the main bee diseases and pests from the signs mentioned on the posters.
- The panel devoted to diseases structures the content into bacterial diseases, acarioses, viral diseases and other diseases.
- For European foulbrood, the poster mentions patchy brood as well as dead larvae in open brood, with a yellowish to dark brown-black coloration.
- For American foulbrood, it indicates patchy brood, sunken and perforated cappings, as well as larvae that decompose into a brown mass forming a thread.
- Varroosis is described in particular by patchy brood, numerous varroa on the bottom inserts, as well as varroa on the bees and on the frames.
- Among the viral diseases, the poster mentions in particular atrophied wings and a shortened abdomen for deformed wing virus (DWV), trembling bees that are completely black, hairless and shiny for chronic bee paralysis virus (CBPV), as well as larvae taking on a sac-like shape for sacbrood virus (SBV).
- Under other diseases, the poster mentions chalkbrood with mummies at the entrance, as well as diarrhoeal diseases with traces of droppings on the alighting board and the frames; it also states that colonies weaken and die.
- The second panel is devoted to the following pests: Asian hornet, wax moths, small hive beetle, varroa mite and Tropilaelaps mite.
- For the Asian hornet, the poster gives the size, several colour criteria and the following explicit instruction: Report suspected sightings at: www.frelonasiatique.ch.
- The small hive beetle is identified as an epizootic disease to be controlled (mandatory reporting); the poster mentions eggs and larvae in the hive, larvae up to approx. 10 mm long, gnawed combs without silky galleries and adult beetles 5–7 mm long.
- For the wax moths, the poster mentions the presence of silky galleries in the combs, black droppings on the bottom inserts and banded brood.
- The comparison between Varroa and Tropilaelaps highlights that varroa has an oval shape and moves slowly and is visible on worker bees in the event of heavy infestation, whereas Tropilaelaps has an elongated shape, moves quickly, is present in the brood and is only rarely visible on worker bees.
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Summary prepared on the basis of Practical Guide 01 (01/2026). Last checked: 03/2026.
See also:
- Practical Guide: 2 Diseases and pests
- Recognising bee diseases
- Practical Guide: 2.8 Varroosis
- Practical Guide: 2.3 Small hive beetle
- Practical Guide: 2.7 Asian hornet
- Practical Guide: 2.6 Wax moth
