AAron wrote:
 
 I seem to recall that there were problems with formic acid
prompting
> queen rejection and/or supercedure if used in uncontrolled or high
> concentration, which is why it was not a favorable means of varroa
> control.
 
Hi Aaron and beekeepers:
 
I have been doing research on Formic acid use to control tracheal
mites for the last 3 years. Liu and Nasr (Amer. Bee J. , 132: 666-
668, 1992) found that three applications of 20 ml 65%
formic acid / hive box at 5-7 days intervals are effective against
tracheal mites. Use of 85% formic acid resulted in bees killing
their queens. In canada, Beekeepers used spray guns to deliver the
recommended dose on absorbing paper towles or on the bottom board.
Our beekeepers in Ontario had bad experience using spray guns.
Because of the acid effects on the plastic material of the gun, the
guns had mechanical breakdown during spray, spillage of the acid on
the applicators' hands, and appplying over dosages of formic acid. In
addition, application of acid on the bottom board did give bees a
chance to get out when it gets hot. Bees walked through the acid and
burn their feet. We had one beekeepers lost 1-2 Lbs/hive from this
type of application.
These difficulties prompted us to develop a safe method to apply an
effective dose of formic acid to bee colonies. We developed the Mite
Wipe Pads which were easy to prepare, and delivered accurate effective
doses to bee colonies. Overall, Mite Wipe reduced the beekeepers'
risk of using formic acid in their hives. Also, we stayed away from
applying the acid on the bottom board to avoid any catastrophic damage
to the bees when it gets hot. These data are reported in the 94
Annual report to the Ontario Beekeepers' association " Tracheal mite
resistance technology transfer by M. Nasr". The description given by
Allen Dick is our research results which were conducted in Guelph,
Ontario and published in Hive Lights.
 
Clark, 1994 (AM. Bee J.134: 829) and Szabo, 1994 (Am. Bee J. 134:837-
838) found that 6-7 applications of formic acid were effective against
varroa mites.
 
formic acid safety: Formic acid is cytotoxic, corrosive, and can
damage the skin and eyes on contact. Remember that bees are animals
too. The issue of safe application should consider both the
applicator and the bees. Use of high concentraion can disturb the
phormone system in the hives and make bees leave the hives. From
my observations, I found dehydrated eggs, dead young larvae, and dead
queens when I used 85% formic acid.
 
My advice is:
Always read and follow label instuctions when using any product near
your hives.
 
For the New Device, I would like to get a copy of the data which show
the efficacy against mites and side effects on bees???
 
 
Medhat Nasr, Ph. D.
 
Ontario Beekeepers' Association
401-40 Vanier Dr.
Guelph, Ontario.
N1G 2X7