The effects of powdered sugar varroa control treatments on Apis mellifera colony development

Abstract

SUMMARYDusting colonies with powdered sugar, wheat flour or other dust materials for the control of varroa have been reported in the apicultural literature. High levels of mite drop have been obtained by sugar dusting adult bees. It was also shown that in dusting adult bees, no sugar particles entered the T2 spiracles and their tracheal ducts. In the present study, the impact of powdered sugar dusting on the number of both capped brood cells and adult bees was studied. During July in a Finnish apiary, 12 honey bee (Apis mellifera) colonies were dusted with 10–20 g of powdered sugar at 3-, 7- and 14-day intervals. Another 6 colonies were left untreated as control colonies. An additional 6 colonies treated with fluvalinate (during the previous autumn) formed the chemically treated control. Number of capped brood and adult bees were recorded during the summer. There were no significant differences among the sugar-treated and untreated control groups in both the number of capped brood cells (P = 0.168) and additional number of adult bees (population growth, P = 0.78), 18 days after the start of the experiment. Data analyses demonstrated that there is no obvious side effect of dusting on colony development. No queen supersedure occurred during July in the colonies under sugar treatment.