Identification of Aggregation Pheromone in Odontothrips loti (Thysanoptera: Thripidae)

Pheromone trapping is an interspecific, active at low concentrations, eco-friendly pest management strategy that has been widely used for population monitoring. Pheromones have only been validated for a few species in Thysanoptera and the pheromone components of Odontothrips loti Haliday are still unclear. In our study, we have identified (R)-lavandulyl (R)-2-methylbutanoate from male O. loti headspace volatiles by gas chromatography-mass spectrometry (GC-MS), which was structurally similar to the known reported aggregation pheromone of Megalurothrips sjostedti. Y-tube olfactometer assays showed that both male and female adults O. loti were significantly attracted by synthetic (R)-lavandulyl (R)-2-methylbutyrate, implicating as an aggregation pheromone. Additionally, electroantennogram responses of O. loti increased with increasing doses of synthetic (R)-lavandulyl (R)-2-methylbutyrate. This is the first report of a male-produced aggregation pheromone in O. loti, from genus Odontothrips. The discovery of aggregation pheromone of O. loti as a primary pest of alfalfa will provide the possibility of monitoring and early warning in alfalfa grass fields and is expected to be used for integrated management for O. loti.