ABSTRACT
The effectiveness of aqueous solution of malathion 5 ppm was tested against Varroa mite under field conditions in both nuclei and Langstroth hives. Honeybees of nuclei were kept confined during the experiment and there after they were killed, to estimate the total number of parasites. In the case of Langstroth hives, honeybees were not confined and only a part of them was killed after the end of the experiment. One treatment with the above preparation was enough to kill 99% of mites in nuclei while a second one was necessary to reach the same level of mortality of mites in standard hives. On the other hand malathion can be kept dissolved in different organic solvents at least for 6 months without losing of its effectiveness against the Varroa mite. The significant of these findings into applied beekeeping is discussed.
