VarroMed
Behandlungsmittel
VarroMed is a ready-to-use dispersion for trickling that combines two organic acids: 44 milligrams of oxalic acid and 5 milligrams of formic acid per milliliter.
VarroMed is a ready-to-use dispersion for trickling that combines two organic acids: 44 milligrams of oxalic acid and 5 milligrams of formic acid per milliliter. Other ingredients include sugar syrup, propolis tincture, star anise oil, lemon oil and citric acid. The product is centrally authorized in the European Union.
The acaricidal effect comes essentially from the oxalic acid. The added formic acid is present in such a low concentration that no neuroexcitatory effect of its own was observed in studies. Rather, it is intended to prolong the duration of action of the oxalic acid and improve tolerability. This leads to an important point for practice: a mite-killing effect in the capped brood is not to be expected from VarroMed. Anyone who takes the formic acid content to mean an effect on the brood misunderstands the product.
Depending on colony strength, 15 to 45 milliliters per treatment are trickled onto the bees in the occupied spaces between the combs of the brood chamber. Up to nine treatments per year are authorized, spread over spring, late summer and one treatment in late autumn or winter. If brood is present in spring or late summer, the treatment is repeated every six days depending on the mite drop, in order to cover one to two mite cycles and also catch the mites that leave the cell with the emerging bees.
The determined efficacy averaged just under 89 percent in late autumn and winter, just over 92 percent in spring and 85 percent in late summer. As a side effect, increased mortality of the workers was observed very frequently, which rose with increasing dose and repeated treatment. With longer treatment periods or when the maximum of nine authorized treatments was used up, negative effects on the lifespan and performance of the queen and on colony development could not be ruled out. Frequent treatment is therefore not a safe strategy.
A practical advantage over self-prepared sugar-containing oxalic acid solutions is the shelf life: the bottle can be used for 30 days after first opening, whereas self-made sucrose solutions must be used up immediately. Because both acids contained are water-soluble, there is no accumulation in the wax. When used properly outside the nectar flow, the withdrawal period for honey is zero days; use during the nectar flow is a contraindication. The dispersion irritates skin and eyes, so acid-resistant gloves and safety goggles must be worn.
Sources (4)
- Europäische Arzneimittel-Agentur: VarroMed, Zulassungsunterlagen und Produktinformation
- Europäische Union, Community Register: VarroMed, Anhang I bis III (deutsche Fassung)
- Emmerich, I.: Zugelassene Arzneimittel für Honigbienen in Deutschland, Berliner und Münchener Tierärztliche Wochenschrift 2018
- LLH Bieneninstitut Kirchhain: Infoblatt Varroazide