Red Sunflower Seed Weevil Responses to Conspecific and Host Volatiles

Goals / Objectives
(1) Determine volatiles emitted by male, female and mixed-sex groups of adult red sunflower seed weevils, and (2) Assess physiological and behavioral responses to conspecific and host volatile blends and components.

Project Methods
In recent years, the red sunflower seed weevil has been the most damaging insect for the primary sunflower-producing states of North Dakota and South Dakota. Unlike other significant sunflower pests, basic tools for population monitoring (e.g., insect pheromone traps) are not available for red sunflower seed weevil. However, prior research suggests adult weevils respond to both conspecific and host volatiles. As a first step towards developing tools that allow growers to more easily monitor seed weevil populations, adult weevils will be used in various experiments to understand volatile cues in their environment and their responses. Solid phase microextraction (SPME) will be used to collect volatile compounds which will be identified using gas chromatography coupled with mass spectrometry (GC-MS). The perception (physiological response) of weevils to volatiles will be tested using electroantennography (EAG). Based on physiological responses to conspecific and host volatiles, additional behavioral tests will be conducted. This work is intended to complement the current CRIS project (3060-21000-043-000-D) Subobjective 2A â¿¿Evaluate susceptibility of sunflowers to insect pests and develop genetic markers for host plant resistance traits.â¿ The results should help determine whether new monitoring tools, such as pheromone traps, can be developed that would permit improved management of this key insect pest.