Electrophysiological responses of male and female Amyelois transitella antennae to pistachio and almond host plant volatiles

The polyphagous navel orangeworm, Amyelois transitella Walker (Lepidoptera: Pyralidae), is a major insect pest of almonds and pistachios in California (USA). Amyelois transitella moths have proven difficult to monitor and control for over 5 decades; however, recent reports indicate progress towards attractants using pheromone or semiochemical blends. Despite advances of a host plant volatile attractant blend that is effective for monitoring moth populations in almond orchards, the blend's attractancy and capture efficacy of A.transitella has not translated to pistachio orchards. The apparent orchard specificity of A.transitella to the blend suggests a different composition of host plant volatiles is needed to either improve the current blend or a new blend formulation is required for monitoring in pistachio orchards. One objective of this study was to evaluate available individual host volatiles via a standardised puff method in combination with electroantennographic analysis. In total 105 volatiles were evaluated individually for their ability to elicit an electrophysiological chemoreception response from excised male and female A.transitella antennae. Male antennae responded significantly higher to alcohols, aldehydes, alkyls, aromatics, and ketones. Female antennae responded significantly higher to benzenoids, monoterpenes, sesquiterpenes, and short-chain alcohols.