Toxicity of oxalic acid on in vitro reared honeybee larvae

Varroa destructor is considered as a serious pest of honeybees (Apis mellifera) and its resistance to acaricides has been reported since the early 1990s. Because large colony loses are yearly reported from over the world, new methods of treatment for Varroa mites are still in focus of many scientists. In our bioassay, we determined the lethal concentration 72 h LC50 of 2.425% oxalic acid solution following single spray exposure of honeybee larvae under laboratory conditions (Guideline OECD 237, 2013).