Akademik Veri Yönetim Sistemi
AMERICAN BEE JOURNAL, cilt.147, sa.6, ss.535-539, 2007 (SCI-Expanded)
The efficacy of thymol and oxalic acid applied with three different delivery methods for the control of the honey bee parasitic mite Varroa destructor was evaluated. The products were applied alone or in combination and the results were correlated with climatic variables (temperature and humidity). The miticides were applied as dust, diluted in sugar syrup trickled onto the bees, and dissolved in ethanol embedded in vermiculite blocks. The best results were those of thymol applied in dust (83.15 +/- 2.0%) and in vermiculite (76.11 +/- 4.5%). The lowest efficacies were those of the oxalic acid treatments (< 40%). The efficacy of combined miticides was not higher than that of single-product treatments. Additionally, a high number of mites were killed during the first three days of miticide applications, but there was no difference between the number of mites falling after three days of miticide applications in treated colonies with that of control colonies. A positive correlation was found between temperature and mite mortality for the thymol in dust and for the thymol in vermiculite methods (r = 0.63 and r = 0.59, respectively). Conversely, a negative correlation was found between humidity and mite mortality for thymol applied in dust or in vermiculite (r = - 0.60 in both cases). Mite mortality in oxalic acid treatments did not show correlation with climatic variables, except when combined with thymol and applied in vermiculite blocks (r = 0.53). These results suggest that thymol in dust and in vermiculite provide an acceptable level of varroa mite control in honey bee colonies during early fall in Northern climates. The application of these treatments during warm and dry days might improve the efficacy of mite control. More methods of delivery need to be studied to increase the time of release and the efficacy of natural miticides in honey bee colonies.