Combining An Artificial Break In Brood Rearing With Oxalic Acid Treatment To Reduce Varroa Mite Levels

摘要

Sixty-two colonies were set up to test the hypothesis that Varroa control with oxalic acid (OA) can be enhanced by combining treatment with late summer requeening. Each colony consisted of two full depth boxes with nine frames per box. All colonies were queen right at the beginning of experiment and had brood present. Approximately 300 adult bees were collected pre- and post-treatment to calculate mites-per-bee. This experiment consisted of four treatment groups, requeen plus OA, requeen only, OA only, and controls (untreated). Queens were caged in the requeen treatment groups five days prior to placing a sealed queen cell in the colonies. This provided a period of 18-21 days without egg lying, which allowed most of the brood present to emerge. A1.7oz (50 ml) application of a 3.0% OA sugar water solution (suganwater) (1:1) (w:w:w) was applied to the requeen plus OA, and OA only treatment groups. The OA solution was trickled from above the frames into the bee-ways with a 3.4 oz (100 ml) syringe. Post-treatment alcohol samples were taken four days after treatment. The results indicate that combining late summer requeening with OA treatment significantly reduced mites compared to untreated colonies, colonies that are requeened but not treated, and colonies only treated with OA. Although we had a significant decrease in the treatment group that was requeened and treated with OA, we found evidence that the presence of brood is not the only factor affecting the efficacy of OA treatments.