European foulbrood of bees

Page last updated: Wednesday, 23 November 2022 - 2:32pm

Please note: This content may be out of date and is currently under review.


Diagnosis can only be confirmed in the laboratory by smears taken from infected larvae or a honey test.

In selecting suitable larvae, it is important to select those that are at the initial stage of infection, before collapsing in the cell. Collapsed larvae may be invaded by secondary bacteria, which may prevent accurate diagnosis.

Larvae in the initial stage of infection often turn with their backs facing towards the cell opening, so that the mid-gut is clearly visible.

Closer examination of the infected mid-gut may show that the gut is enlarged and white, instead of the yellow-brown seen in healthy larvae.


European foulbrood disease could possibly be eradicated if it occurred in an isolated area. Eradication may involve the total destruction of all colonies within the affected area.

Should the disease become widespread, eradication may not be possible and it may be necessary to adopt control measures using antibiotics. Antibiotics, combined with good management, have been shown to control but not eradicate the disease.

It is an offence under legislation to feed antibiotics to bees without the written approval of an inspector. It is also an offence to introduce bees, hives and hive products into the state. Penalties apply for both offences.

Hygiene is important in limiting or preventing the spread of the disease. Beekeepers should maintain good apiary hygiene, as follows:

  • Avoid the introduction of bees and equipment from unknown sources.
  • Avoid exposing honey combs or equipment to robbing. Store and fumigate spare equipment away from robber bees.
  • Watch for signs of diseases.
  • Report any brood abnormalities immediately by telephone to the Apiary Coordinator at  European foulbrood is a declared pest and beekeepers are legally required to report them.
  • Submit slide smears and a sample of comb to DDLS – Animal pathology, the department's diagnostic laboratory service.

How to submit samples

  • Obtain microscope slides from the Apiary Coordinator or DDLS – Animal pathology at South Perth.
  • Identify the hive from which the samples are taken.
  • Select a piece of affected comb not less than 75mm square.
  • Write your name and hive identification number on a clean microscope slide with a permanent marker.
  • Select two larvae showing early signs of the suspected disease. Place one at each end of the slide.
  • Mash the larvae thoroughly, using a clean match for each larva.
  • Remove the bulk of the larval remains from each mashed larva, leaving a separate patch of milky liquid, about the size of a 5 cent coin, at each end of the slide.
  • Allow to dry, but protect from the sun at all times.
  • Submit five slides, each containing two larvae, for diagnosis.
  • Pack the slides to protect them from breakage, and the comb to prevent leakage, and post with completed Report of outbreak of honey bee diseases form to:

DDLS – Animal pathology
Department of Primary Industries and Regional Develoment
3 Baron-Hay Court
South Perth  WA  6151


Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080


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