A friend writes:
> Don't forget the use of formaldehyde against AFB in the 1930s.

I neglected to mention this one because I didn't have the references.
It seems to have been been discussed widely in 1903 and 1904 in
"Gleanings". Many methods were tried to fumigate combs with
formaldehyde, liquid or vapor. This went for at least 30 years, always
trying to get just the right method.

For example, in 1930, the "American Bee Journal" ran an article on
fumigating with formaldehyde vapor called "Two Years' Experience With
Gas-treated Combs" and another with the bold title: "The Permanent
Eradication of American Foulbrood".

But by 1941, R. E. Foster wrote:

> The State Plant Board of Florida first undertook eradication or control of American foulbrood in 1919. It was the first agency to require destruction by burning as the only adequate means of dealing with the disease. This practice is now almost universally followed and recommended by apiary inspectors throughout the country.

* * *

As to actually medicating the bees themselves, this is mentioned in
the 1908 "ABC & XYZ":

> Two antiseptics have been recommended. One is carbolic acid and the is naphthol beta. The former has such a strong odor that it is with difficulty, if at all, that the bees will take syrup medicated with it; but they offer no objection to whatever syrup having naphthol in it. I would advise every beekeeper who has once had foulbrood in his apiary to medicate all syrups he feeds to his bees. This ought to put a quietus on the worst nenmy with which bee-keepers have to contend. <

So chemicals have been fed to bees for at least 100 years

-- 
Peter L. Borst

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