> >Oxalic acid is hurting (weakening) bees and open a gate for secondary > > diseases ( for instance - virus). > > so where is this documented? Apidologie 35 (2004) 453-460 DOI: 10.1051/apido:2004037 Cell death in honeybee (Apis mellifera) larvae treated with oxalic or formic acid Ales Gregorca, Azra Pogacnika and Ivor D. Bowenb a Veterinary Faculty of the University of Ljubljana, Gerbiceva 60, 1000 Ljubljana, Slovenia b Cardiff School of Biosciences, Preclinical Building, Cardiff University, PO Box 911, Cardiff, CF10 3US, UK Abstract - The effects of oxalic (OA) and formic acids (FA) on honeybee larvae in colonies were assessed and evaluated. Cell death was detected by the TUNEL technique for DNA labelling. In 3- and 5- day-old larvae exposed to OA, cell death was found in 25% of midgut epithelial cells 5 h after the treatment, using an "In situ cell death detection kit, AP" (Roche). The level of cell death increased to 70% by the 21st hour and the morphology of the epithelium remained unchanged. Fifty hours after the application, cell death was established in 18% of the epithelial cells of the 3-day-old larvae and had increased to 82% in the 5-day-old larvae. A "DeadEnd" apoptosis detection kit (Promega) showed sporadic cell death mainly in the larval fat body 5 h after treatment. Twenty-one hours after the OA application cell death was found in 4% of the larval midgut epithelial cells. Evaporated formic acid induced extensive apoptotic cell death in the peripheral, cuticular and subcuticular tissues that preceded the cell death of the entire larval body. > here in Ontario it works like a charm and is highly recommended You probably don't have viruses aroud. All beekeepers who lost bees probably because of virus - (50 - 100%) in som areas in Sweden used oxalic acid. No beekeepers using Apistan were affected with big losses. \vov -- Visit www.honeybeeworld.com/bee-l for rules, FAQ and other info ---