Winter Bee Mites Treatment - Oxalic Acid Dribble

Varroa mite on a nurse bee

Warm winters are hard on honey bee hives. Instead of staying clustered, honey bees send out foragers any time the weather is warm enough for flight. This reduces the life span of the winter bees and quickly uses up colony resources. The colony might end up raising brood well into late fall and winter to replace foragers.

A prolonged and mild winter can play havoc with the varroa mite numbers within a honey bee colony.

The last few winters in Northwest Ohio came hard and fast. We did not get a reprieve until Spring time. This year, I had the perfect opportunity to try Randy Oliver's (Scientific Beekeeping) recommended winter mite treatment - an oxalic acid dribble.

I read through his power point presentation. Then I used the Oxalic Acid Treatment Table and made the 1 L batch that treats about 20 colonies. I used a handheld 2 gallon sprayer
(shown on left).

Handheld sprayer for bee mite treatment -
oxalic acid dribble

At the lowest setting, my sprayer dispenses about 2.5 ml per "pass". I made 2 passes per seam of bees. I also did not treat with more than 50 ml per hive, since Randy mentioned in his presentation that Europeans recommend not applying more than that due to the colder and longer winters.

It took us about 1 hour to treat 9 hives. We should be able to see the effect in the Spring.