Treating packages with oxalic acid

10/12/2017

The folks at the University of Georgia have investigated the treatment of honey bee packages with oxalic acid to kill the mites. You can read an article on this at Bee Culture magazine. I followed up with them and they provided a copy of the research paper on Spraying Packages with Oxalic Acid (file below) upon which the article was based. In addition, some hands-on advice on how to treat a package with a spray bottle, which I’ve copied below.

The correct dosage is 3.0mL of solution per 1000 bees. A two pound package has about 7,000 bees so 21mL per 2 pound package. To make the solution you dissolve 35 grams of oxalic acid with 1 liter of warm 1:1 sugar/water. Evenly apply the 21mL to both sides of the package through the screen. 21mL is not a lot of liquid (1.42 tablespoons) so care must be taken if you use a spray bottle. Over treating can kill bees.
Make sure to spay heavily with sugar water a few hours before treatment to limit the bees eating the oxalic mixture.
Make sure the bees remain in the package, with plenty of food, for 72 hours before hiving them. The oxalic needs time to work. Keep the bees in a cool, dark, and well ventilated area.