Formic acid residues in honey in relation to application rate and timing of formic acid for control of tracheal mites, Acarapis woodi (Rennie)
Liu, T.P.; Chu, L.T.Y.; Sporns, P.
American Bee Journal 133(10): 719-721
1993
ISSN/ISBN: 0002-7626 Accession: 002386707
Five honey bee (Apis mellifera) colonies (A) in Alberta, Canada, infested with A. woodi, were treated twice in spring (May-June) with 88% formic acid (FA) at a dose of 22 g per Langstroth hive box. Four colonies (B) were treated 3 times in summer (late June-July) with 22 g per box of 65% FA. Honey taken from both treatments in mid-August was tested for formic acid residues: these averaged 78 ppm in A (range 18-115), and 363 ppm in B (range 262-492). Summer treatment is therefore not recommended. FA content of honey samples from colonies not treated varied with location, averaging 60 ppm and 61 ppm in two Alberta surveys, but 110 ppm in honey from British Columbia.