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Viruses

Chronic bee paralysis

Chronic bee paralysis virus (CBPV)

Severity : High Spring and summer, often after a strong flowReview in progress
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Key points

  • A viral disease of adult bees, also known as "black robber" or hairless black syndrome.
  • Trembling, crawling bees; black, shiny, hairless bees.
  • Spreads by contact, especially in crowded, very populous colonies.
  • On the rise in several countries; no treatment, act on the colony.

Chronic bee paralysis affects adult bees. It can kill thousands of bees in a few days and often strikes the strongest colonies, when you least expect it.

The agent

Chronic bee paralysis virus (CBPV) spreads mainly through direct contact between bees, through tiny wounds in the cuticle: lost hairs and rubbing in an overcrowded hive make infection easier1. Cases are increasing in several countries, and apiaries with a high density of colonies seem more affected2.

Two forms of symptoms

Trembling form. Bees shaking, wings spread, swollen abdomens, unable to fly. They crawl on the landing board and in the grass, often in small groups.

Black form. Hairless, black, shiny, smaller bees that are harassed and thrown out by their nestmates.

In severe cases, a carpet of dead and dying bees builds up in front of the hive.

Photo needed — Black, shiny, hairless bees on the landing board.

Do not confuse with

Pesticide poisoning can cause similar signs: trembling, dying bees outside the hive. If several colonies are affected at once, think of poisoning and contact the veterinary authorities. A laboratory diagnosis settles the question.

What to do

  1. Avoid overloading an apiary with colonies and limit migratory moves.
  2. Give space in time: do not let colonies crowd after a flow.
  3. Remove sick combs and bees if needed, and requeen colonies that relapse.
  4. Control varroa and keep good stores3.

References

  1. Ribière M., Olivier V., Blanchard P. (2010). Chronic bee paralysis: a disease and a virus like no other? Journal of Invertebrate Pathology 103: S120-S131.
  2. Budge G.E. et al. (2020). Chronic bee paralysis as a serious emerging threat to honey bees. Nature Communications 11: 2164.
  3. FAO, IZSLT, Apimondia, CAAS (2021). Good beekeeping practices for sustainable apiculture. FAO Animal Production and Health Guidelines No. 25.

Updated : October 8, 2026
Written by : Apisanitas editorial team
Reviewed by : Review in progress