Chemical Treatments
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Fumidil 'B'

Fumidil 'B' is not registered for use in the U.K. It was withdrawn in 2012.
There will be many books, leaflets, articles, etc in circulation for some years to come. As of December 2022 it is still available online from suppliers in other countries. Please don't be tempted to buy it as residues may be detected.

General note on chemicals: I do not endorse or advise on chemical treatments, as I am not qualified to do so and there may be dangers beyond my control. New products may be introduced or existing ones withdrawn, so it is difficult to keep up with current information on a website such as this. As many of the chemical pages were generated by Dave Cushman, I am leaving the content mainly as left by Dave for historical purposes only, which may mean information is out of date and unreliable. The user should seek guidance from other sources and satisfy themselves regarding safety and legality. Roger Patterson.

For the prevention of Nosema disease in honey bees.

Manufactured By:- Abbott
Distributed & Marketed By:- CEVA Ltd., 3 Rhodes Way, Watford, Herts. (to whom all enquiries should be addressed.)
Available from the UK appliance trade.
Data Sheet Ref's:- PL 3974/4013, 09250/46/3, 09-250/79
Date of Issue of Data:- Unknown (thought to be 1979).

I neither endorse nor condemn this product. The information as published here is a matter of public record. The information is placed here for the education of those that wish to read it.
BEFORE you obtain or use the material concerned please ascertain the legality of doing so in your location as the product may or may not be approved in your geographic State or Country.

Fumidil B is Abbott's name for bicyclohexyl-ammonium fumagillin:- a soluble salt of an antibiotic produced by fermentation of Aspergillus fumigatus. This antibiotic has been found to possess a specific activity against the protozoon Nosema Apis, the cause of Nosema disease in honey bees.[1] The antibiotic prevents the reproductive stages of the parasites from attacking the epithelial cells of the digestive stomach of the bee.

The 3 colony pack shown at right contains a polythene tub with a 'lever off' lid. The fine, but granular powder contained in the tub has a cream colouration.

   Fumidil 'B' Pack

Fumidil B has no effect on the spores or the resting stage of Nosema Apis, and must therefore be made available in the food of the bees for three to four weeks to free the colony population of infection. To prevent reinfection from spores carried by the combs the latter should be replaced by clean combs early in the spring and then (the old combs) should be decontaminated by exposure to the vapour of commercial formalin (or glacial acetic acid if they contain stores of honey or pollen) before they are used again.[2]

Fumidil B is effective when fed in syrup in the autumn. [3] It is best used then as a preliminary to the transfer of the bees on to clean combs in the spring or as a precautionary measure in the autumn following the transfer.[4]


Directions for use

Based on results obtained at the Rothamstead Experimental Station.

Each colony to be treated should receive approximately 166 mg of fumagillin activity (one third of the contents of a 0.5 gm vial), administered in a syrup containing 14 lb of sugar in 7 pints of water.

Precise measurement is not essential since a "rough third" of the 0.5 gm vial (approx. a desert spoonful) is more than adequate for the treatment of the average colony.

It is easier to dissolve sugar in warm water, however it is important that Fumidil B is NOT subjected to a temperature higher than 49 deg C (120 deg F) during any stage of the mixing operation.


The large pack contains 9.5 gm of fumagillin activity which makes sufficient syrup to treat 54 colonies. The contents of this pack should be dissolved in 47.5 gallons of water to which 6.75 cwt. of sugar should be added as described above.

How Supplied

Fumidil B List No. 8692 (in a suitable buffered formula) is supplied in two pack sizes:

Dave Cushman.

Originally written by Dave Cushman. Edited by Roger Patterson.

Page created pre-2011

Page updated 13/12/2022