Behavioral Evidence and Olfactory Reception of a Single Alarm Pheromone Component in .

is a major herbivore insect in the fruit orchards of China that has become a devastating invasive pest in North America and Europe since its accidental introductions in the 1990s and 2000s， respectively. Like other hemipteran insects， releases defensive chemicals against natural enemies， including ()-2-decenal， which is an aldehyde associated with alarm pheromones. In this study， a series of electrophysiological and behavioral tests were conducted to characterize the alarm functions of ()-2-decenal among adults and nymphs. An antennal transcriptome was obtained from a Chinese population， and 44 odorant-binding protein () genes were annotated. Among them， five putative alarm pheromone-binding proteins were screened and were extremely consistent with their homologs from US populations. These five OBPs were later expressed in a heterologous expression system， harvested， and then challenged with ()-2-decenal in a binding assay. All five OBPs showed high binding activities to ()-2-decenal， which demonstrated its behavioral significance as a defensive component in ， as well as being the first report of its olfactory reception. These findings will help develop behavioral-mediating tools as part of integrated pest management approaches to control this invasive pest.