An odorant receptor-derived peptide biosensor for monitoring the migratory locust Locusta migratoria by recognizing the aggregation pheromone 4-vinylanisole

The migratory locust, Locusta migratoria (L. migratoria), is one of the most damaging agricultural pests worldwide. Currently, the monitoring of L. migratoria largely depends on the labor-intensive field survey and remote sensing with insufficient spatial precision. A sensitive and real-time monitoring technology is desired for early detection and efficient management of the infestation. Here we characterized peptide sequences of the L. migratoria odorant receptor that can recognize the aggregation pheromone 4-vinylanisole (4 VA) by molecular docking. Next, we designed odorant receptor-derived peptides (ORPs) and fabricated an ORP-biosensor capable of real-time monitoring of gaseous 4 VA with high sensitivity (∼1 ppb) and selectivity. Furthermore, we demonstrated that the ORP-sensor could detect a single live L. migratoria and observed that the feeding behavior of L. migratoria accelerated the release of 4 VA, which provided a new evidence for the viewpoint that locust aggregation behavior was regulated by food resources. The findings suggest the potential applications of ORP-sensors in entomology research, infestation control and other areas where the detection of a gaseous substance is needed.