Locust plagues threaten agricultural and environmental safety throughout the world. Aggregation pheromones have a crucial role in the transition of locusts from a solitary form to the devastating gregarious form and the formation of large-scale swarms. However, none of the candidate compounds reported meet all the criteria for a locust aggregation pheromone.
Using behavioral assays, electrophysiological recording, olfactory receptor characterization and field experiments, a research team led by Prof. KANG Le at Institute of Zoology of Chinese Academy of Sciences demonstrated that 4-vinylanisole (4VA) (also known as 4-methoxystyrene) is an aggregation pheromone of the migratory locust (Locusta migratoria). Both gregarious and solitary locusts are strongly attracted to 4VA, regardless of age and sex. Although it is emitted specifically by gregarious locusts, 4VA production can be triggered by aggregation of four to five solitary locusts. It elicits responses specifically from basiconic sensilla on locust antennae. The study also identified OR35 as a specific olfactory receptor of 4VA. Knockout of OR35 using CRISPR-Cas9 markedly reduced the electrophysiological responses of the antennae and impaired 4VA behavioral attractiveness. Finally, field trapping experiments verified the attractiveness of 4VA to experimental and wild populations. These findings identify a locust aggregation pheromone and provide insights for the development of novel control strategies for locusts.
The study was published in Nature on August 12. Prof. KANG Le is the principal of College of Life Sciences of University of Chinese Academy of Sciences.
