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Insect ID Clinic


Honey Bee Diagnostic Services

European Foulbrood

Causative Agent: Streptococcus pluton (Bacteria)

Range: Wherever European honey bees occur (some reports from African bees as well)

Life cycle:

  • This disease is more often a problem in the spring.
  • Only fatal to young uncapped larvae.
  • Later stages can be infected but the disease only affects the silk glands, and capping may be sparse but is not fatal.
  • Fatalities typically occur when the bees are only 4 or 5 days old.
  • After the larva dies the bacteria enters a spore stage. Unlike American Foulbrood this stage cannot survive extended periods of time (typically no more than 6 months).
  • Dead larvae remain soft, pliable and usually twist/curl in the cell. Workers can easily remove the cadavers.
  • Progression of color: white→yellowish white to brown→dark brown/black.
  • Consistency of dead brood is watery (rarely sticky or stringy) and granular.


  • European Foulbrood is most common a few weeks after a colony looses a high number of the adult workers due to pesticides or other causes. If a cause can be identified, steps should be taken to avoid it reoccurring in the future.
  • Treatment with Oxytetracycline can kill this disease but several precautions must be taken to prevent the contamination of honey and other products.


Odor is not a reliable method of distinguishing this disease

Irregular brood pattern can be a sign of a problem (but not necessarily European Foulbrood)

Other Useful Sites:

Information and Pictures of American, European and Sac brood Diseases

Mid-Atlantic Apiculture Research & Extension Consortium Disease Control

References used:

Root, A. I. (1990) The ABC & XYZ of bee culture 40 th ed. A.I Root Co. Medina, OH.

Morse, R.A. & R. Nowogrodzki (eds). 1990. Honey bee pests, predators and diseases . Cornell University Press Ithaca , NY .

Printable pdf version


April 3, 2008