Hello George & All,
I don't disagree with what George has posted but the real world of
beekeeping is a bit different.
Menthol:
When Menthol came we were getting hit hard with tracheal mite losses. We
were told even though Menthol was temperature dependent there would be
enough warm days for the menthol to work. All commercial beekeepers in
Missouri went to Menthol( largest over 7,000 hives). The losses were not
much better with the menthol than the year before. The USDA then came up
with a cold weather formula using canola oil. Many large beekeepers pull
supers and extract into October. Part of the hives could be treated by the
dates suggested by George 8/15 to 9/1 but only a small part. I know of no
beekeepers in Missouri using the menthol *crystals*. We were told by the
USDA and sellers of the menthol crystals *the first year* that they would
work as long as we had warm days for part of the treatment period. Over
10,000 hives were treated with heavy losses. The menthol crystals worked
(and still do) great in the south. The farther north you go the less
dependable they are EXCEPT when you put the menthol on in August in
Missouri.
Bob