Comparative Evaluation of Acaricidal Effects on Varroa destructor during the Spring Season

This study evaluated the corrected efficacy of three acaricide treatments, amitraz spray, oxalic acid fumigation, and fluvalinate strip for controlling Varroa destructor in honey bee( Apis mellifera) colonies during the spring season. In this experiment, all capped brood frames were removed prior to treatment to create a broodless condition, which is typical in early spring honey bee colony condition after overwintering. Colonies received one of the three treatments at 3 times at 1-week intervals, and mite densities were assessed before and after treatment using sticky board and sugar shaking method. Results showed that oxalic acid treatment was the most effective, followed by amitraz treatment, and fluvalinate treatment did not show sufficient level of control. The corrected efficacy obtained using sugar shaking and sticky boards were 33.0-69.5 for fluvalinate, 73.9-91.6 for oxalic acid fumigation, 58.7-74.6% for amitraz spray. All the treatments did not influence the honey bee population size in the colony, indicating the safety of the treatments to the honey bee colonies. Under broodless conditions, oxalic acid fumigation and amitraz spray have been found to be effective, while maintaining colony health, and the use of these acaricides is recommended.