2011 Annual Report
1a.Objectives (from AD-416)
The objectives of this cooperative research project is: a) to determine the efficacy of an innovative formulation of formic acid preparation for controlling Varroa destructor under field conditions, b) to determine its impact, if any, on colony strength, and c) to measure residues in honey.
1b.Approach (from AD-416)
1. The test will be conducted near Weslaco, TX, using USDA-owned colonies.
2. Colonies meeting our criteria for size and health will be selected. These will be treated with: a) nothing, b) NOD product applied to non-supered colonies, or c) NOD product applied to supered colonies.
3. Impact on colonies will be assessed by scoring adult bee strength before and after treatment. During the first 16 days of treatment dead adult workers will be collected from Todd dead bee traps and counted.
4. Efficacy will be assessed by a. counting all mites dropping from colonies during treatment, and b. challenging remaining living mites by applying two known control agents after treatment.
The goal of this project was to test the performance of the NOD product, containing formic acid, in a hot weather environment. Formic acid is volatile and its vapor pressure is dependant on temperature. High levels of formic acid are adverse to honey bee health. A study was conducted in August 2010 in south Texas. All open brood was killed, but queen bees were not. Unfortunately, mite efficacy was low and the product was not considered efficacious. We do not anticipate further work on this product for the control of V. destructor, but we will focus on control of Nosema. A fortuitous observation during this time found that colonies with Nosema ceranae infections had significant lower levels when treated with formic acid.