Identification and Field Bioassay of Rusicada privata (Lepidoptera: Erebidae) Sex Pheromone

Rusicada privata (Lepidoptera: Erebidae) is a major pest insect on Hibiscus syriacus L. (Malvaceae: Malvales), which is usually planted in urban landscapes. Insecticidal control of R. privata is not ideal for urban landscaping due to its harmful effects and risk to human health. Therefore, nonchemical and ecofriendly alternatives are needed. To identify the sex pheromone of R. privata, abdominal tip extracts of male and female R. privata were analyzed by gas chromatography-mass spectrometry. The abundance of 7-methylheptadecane (7Me-17Hy) in female R. privata abdominal tip extracts led us to hypothesize that it is the major sex pheromone. The compound was tentatively identified by a mass spectral library and confirmed by matching retention times and mass spectra of the female-produced compound with those of a synthetic standard. The compounds elicited electroantennographic (EAG) activity. In a field trapping experiment, only synthetic lures containing 7Me-17Hy attracted R. privata males. The EAG activity and field trapping results confirmed that 7Me-17Hy is the sex pheromone of female R. privata. The results will aid in developing sex pheromone-based R. privata control techniques, such as mating disruption.