Research Associate Professor Tennessee State University McMinnville, Tennessee
Flatheaded appletree borers, Chrysobothris femorata (Olivier), are common pests in nursery production and landscape settings. Females commonly oviposit in small nursery trees that are stressed. To deter attacks, nursery producers often apply imidacloprid drench treatments. Studies have shown that both herbicide stress and imidacloprid treatments induce phytochemical changes in nursery trees. The changes induced by herbicide stress may cause a host to be more attractive to flatheaded borers. Additionally, some studies indicate that imidacloprid may cause beneficial changes to plants that result in increased growth. We analyzed the phytochemical changes of red maples (Acer rubrum L.) in response to applications of imidacloprid, two common herbicides (glyphosate and nonanoic acid), and combinations of imidacloprid and the herbicides. The analyzed changes included volatile compound emissions, nutritional and anti-nutritional constituents, and photosynthetic pigments. We also analyzed rates of borer attack in the different treatments. Our results show how treatment application and interactions effect tree phytochemistry and how these applications may alter flatheaded appletree borer host-selection. Understanding the factors that dictate host-selection can provide nursery producers with recommendations for the most effective integrated management strategies for deterring flatheaded appletree borers.
