A scientific note on oxalic acid by topical application for the control of varroosis

Abstract

oxalic acid / varroosis / honeybee / honey / residues Tests on the use of oxalic acid for controlling varroosis (Takeuchi et al, 1983; Zjuman, 1987;Radetzki et al, 1994;Nanetti et al, 1995;Imdorf et al, 1997) Bee mortality was determined using 'underbasket traps' applied to each hive (Accorti, 1994).The mean efficacy of the three treatments with oxalic acid was 95% (± 7.39%) (

Oxalic acid for the control of varroosis in honey bee colonies – a review

“…In one case, even the highest concentration (7% oxalic acid dihydrate, 25-30 mL per hive) did not raise the oxalic acid content of the honey directly after treatment (Mutinelli et al, 1997).…”

“…Repeated treatments with a high concentration (6 and 7%) did not increase the efficacy (Mutinelli et al, 1997); one study even described a reduced mite mortality of 56.2% (Baggio and Mutinelli, 2003b). Mutinelli and Baggio (2002) applied Ipereat, a ready mixed solution containing about 4.2% oxalic acid dihydrate, ethereal oils, propolis and sugar and reported efficacies up to 93.9%.…”

“…A higher oxalic acid dihydrate concentration appeared more suitable in a southern climate. Treatments with 6% oxalic acid dihydrate, 5 mL per bee way, resulted in an efficiency of > 90% and > 95%, respectively, while treatments with 3.1 and 5% oxalic acid dihydrate resulted in < 90% (Ferrero et al, 2004;Mutinelli et al, 1997;Mutinelli and Baggio, 2002;Nanetti and Stradi, 1997;Nanetti et al, 2003a).…”

“…In Southern Europe, oxalic acid dihydrate concentrations up to 7% are tolerated (Gregorc and Planinc, 2001;Mutinelli et al, 1997;Mutinelli and Baggio, 2002;Nanetti and Stradi, 1997;Nanetti et al, 2003a) even if the bee colonies are treated 3 times. No losses of queens were reported and bee mortality did not increase.…”

Impacts of oxalic acid, thymol, and potassium citrate as Varroa control materials on some parameters of honey bees

“…They found that the first two methods were better than cellulose strips. Mutinelli et al (16) found the efficacy of sprayed 5% (w/v) oxalic acid to be higher than that of a topical application. Rashid et al (10) applied oxalic acid in sugar syrup at 4.2%, 3.2%, and 2.1%, and similar work was done using 2.9% oxalic acid (17).…”