09-Lutte biologique contre varroa -III-. Tests de contrôle d'efficacité

A series of videos demonstrates the completion of the biological control method against Varroa mites (a parasite of bee brood) by blocking summer egg-laying. PART I [   • 07-Lutte biologique contre Varroa -I-. Mét...  ] concerns the release (uncaging) of queens held in special boxes developed by Scalvini. PART II [   • 08-Lutte biologique contre Varroa -II-. Mé...  ] shows the dripping of a syrup containing a very low concentration (3.5%) of oxalic acid to eliminate phoretic Varroa mites. PART III [   • 09-Lutte biologique contre varroa -III-. T...  ] tests the effectiveness of the first dripping using two methods. PART IV [   • 10-Lutte biologique contre Varroa-IV- Comp...  ] evaluates the effectiveness after the second dripping and provides some additional discussion. PART V [   • 11-Lutte biologique contre Varroa -V- Cont...  ] inspects the brood of the colonies 25-30 days after the release of the queens. A reminder of the protocol for controlling varroa mites by caging: Day 0: queens are caged. Day 21 after queen caging, there is no more worker brood. Queens are released. First drip of oxalic acid. Day 24 later, no more drone brood. Second drip. All varroa mites are now phoretic, meaning they are sheltering on the bees' bodies. In this state, a weak oxalic acid syrup can eliminate up to 95-98% of the parasites. Oxalic acid (sometimes called sorrel salt) is an organic acid found in honey, rhubarb, beetroot and plants of the Oxalis family, such as sorrel, from which it gets its name.