2011 Annual Report 1a.Objectives (from AD-416) 1. Examine the impact of hygroscopic feeding stimulants on lethality of attracticidal spheres. 2. Assess the attractiveness of integrated visual and olfactory components of attracticidal spheres. 3. Determine the protective capacity of attracticidal spheres. 4. Assess performance of commercial deployment of attracticidal spheres. 1b.Approach (from AD-416) We will use laboratory and field-based experiments to determine the most effective attracticidal spheres for apple maggot fly control. Experiments will encompass inclusion of feeding stimulants, feeding attractants, and host apple volatiles. Ultimate evaluations will be made in commercial apple orchards. 3.Progress Report We have identified areas of improvement to increase the efficacy of attracticidal spheres for apple maggot control. These improvements included optimized visual cues using a refined shape stimulus form, enhanced olfactory cues using additional food-based attractants, i.e., ammonium carbonate, an improved toxicant delivery system based on inclusion of hygroscopic feeding attractants, and a rational deployment strategy. In 2010, spheres which included ammonium carbonate as a feeding stimulus resulted in a rapid decline in overall lethality under field conditions owing to the hygroscopic nature of the material. This led to increased apple maggot pressure in commercial orchards where rainfall was heavy, often necessitating supplemental spray applications. Therefore, in 2011, we have removed ammonium carbonate from the attracticidal sphere formulation. Field efficacy studies are currently being conducted in cooperation with apple growers in New Hampshire, Vermont, New York, and Massachusetts.