Remove honey frames with honey for human consumption and leave the bees with enough food for the duration of the treatment. Preparation of the device:
Remove the lid, add the formic acid to the sponge cloth and close the lid. Once at the apiary adjust the opening of the disc in function of temperature and hive size. Place the dispenser upside down directly over the brood area. Best results are achieved with 2–3 cm space between the dispenser and the top bars of the frames. Adjust opening of the disc after day 2 following the instructions.
Formic acid vapours act fast on Varroa. Varroa mite fall peaks on the second and third day. The use of formic acid may cause brood interruption. Vapours may cause some fatal damage to brood and emerging bees. Occasional Queen loss has been observed with shock treatment and at elevated temperatures. Formic acid acts only while vapours are generated and present. After the treatment vapours are removed by ventilating bees and the action stops. Since formic acid is soluble in water it will be found as residue in honey and nectar present during treatment also in capped honey cells. Feeding during treatment may lead to robbery.
Use safety goggles and protective clothing when working with formic acid