Oxalic Acid 99.6% is used for the control of varroa mites in honey bee colonies using the drizzle method or vaporizer. Apply in late fall to early spring when monitoring indicates treatment is necessary. Can be purchased in 140g or 1kg size.

Solution Method: NOTE: To completely dissolve acid dihyrate, use warm syrup. Dissolve 35g of oxalic acid dihydrate in 1 litre of syrup made from a 1:1 sugar:water (weight:volume) mixture of sugar and water. Smoke bees down from the top bars. With a syringe or an applicator, trickle 5ml of this solution directly onto the bees in each brood box. The maximum dose is 50ml per colony whether bees are in nucs, single, or multiple brood chambers. Under certain unfavorable conditions, eg., weak colonies, unfavorable overwintering conditions, this application method may cause some bee mortality or overwintering bee loss.

Vapourizer Method: Apply only to outdoor colonies with a restricted lower hive entrance. Seal all upper hive entrances and cracks with tape to avoid escape of oxalic acid vapour. When possible, treat while hives are wrapped to ensure they are properly sealed. Smoke bees up from the bottom board. Place 2.0 g oxalic acid dihydrate power into vapourizer. Follow the vapourizer manufacturer's directions for use. Insert the vapourizer apparatus through the bottom entrace. Apply heat until all oxalic acid dihyrate has sublimated.

Always follow label directions and utilize personal protective equipment.