Comparison of population monitoring techniques for the ectoparasitic mite Varroa destructor in honeybee (Apis mellifera L.)

The ectoparasite mite Varroa destructor is the most serious pest of honeybee (Apis mellifera L.). In developing integrated mite management system, monitoring is the first priority. Here, we compared the sugar shaking and sticky board methods for the precise and efficient monitoring of varroa mite. Further, the distribution of varroa mite inside the hive was studied. Along with varroa mite and honeybee colony monitoring, we proposed an economic injury level and action threshold. The sugar shake method was more sensitive, reliable, and efficient regarding cost and labor. Between these two methods, mite densities were significantly correlated with r²=0.815. Between the bottom and super chambers of the hive, mite densities were not different. Even though there was no difference in mite density between each comb, mite densities were significantly higher in the middle part of the comb. The economic injury level of varroa mite in the hive, which was based on the mite densitywhen the honeybee population started to decline, was measured to be 22 per 100 bees by the sugar shake method and 12 per day by the sticky board method. The action threshold was proposed as 11 per 100 bees by sugar shaking and 6 per day by the sticky board method. However, the practical guideline for varroa control is suggested as 5% infestation of varroa mites on adult honeybees in consideration of various uncertainties discussed here.