Beijing Institutes of Life Sciences, Chinese Academy of Sciences, Beijing 100101, China.
Center for Excellence in Biotic Interactions, University of Chinese Academy of Sciences, Beijing 100049, China.
Proc Natl Acad Sci U S A. 2023 Sep 12;120(37):e2306659120. doi: 10.1073/pnas.2306659120. Epub 2023 Sep 5.
Chemical signals from conspecifics are essential in insect group formation and maintenance. Migratory locusts use the aggregation pheromone 4-vinylanisole (4VA), specifically released by gregarious locusts, to attract and recruit conspecific individuals, leading to the formation of large-scale swarms. However, how 4VA contributes to the transition from solitary phase to gregarious phase remains unclear. We investigated the occurrence of locust behavioral phase changes in the presence and absence of 4VA perception. The findings indicated that solitary locusts require crowding for 48 and 72 h to adopt partial and analogous gregarious behavior. However, exposure to increased concentrations of 4VA enabled solitary locusts to display behavioral changes within 24 h of crowding. Crowded solitary locusts with RNAi knockdown of , the specific olfactory receptor for 4VA, failed to exhibit gregarious behaviors. Conversely, the knockdown of in gregarious locusts resulted in the appearance of solitary behavior. Additionally, a multi-individual behavioral assay system was developed to evaluate the interactions among locust individuals, and four behavioral parameters representing the inclination and conduct of social interactions were positively correlated with the process of crowding. Our data indicated that exposure to 4VA accelerated the behavioral transition from solitary phase to gregarious phase by enhancing the propensity toward proximity and body contact among conspecific individuals. These results highlight the crucial roles of 4VA in the behavioral phase transition of locusts. Furthermore, this study offers valuable insights into the mechanisms of behavioral plasticity that promote the formation of locust swarms and suggests the potential for 4VA application in locust control.
同种化学信号在昆虫的群体形成和维持中至关重要。飞蝗利用聚集信息素 4-乙烯基藜芦醚（4VA），特别是群居型飞蝗释放的 4VA，来吸引和招募同种个体，从而形成大规模的蝗群。然而，4VA 如何促进从独居相到群居相的转变仍不清楚。我们研究了在存在和不存在 4VA 感知的情况下，飞蝗行为相变化的发生。结果表明，独居飞蝗需要拥挤 48 和 72 小时才能表现出部分和类似群居的行为。然而，暴露于更高浓度的 4VA 使独居飞蝗在拥挤后 24 小时内就能表现出行为变化。用 RNAi 敲低 4VA 的特定嗅觉受体 ，使群居飞蝗 RNAi 敲低后无法表现出群居行为。相反，在群居飞蝗中敲低 会导致出现独居行为。此外，还开发了一个多个体行为测定系统来评估个体之间的相互作用，代表社会相互作用倾向和行为的四个行为参数与拥挤过程呈正相关。我们的数据表明，暴露于 4VA 通过增强同种个体之间的接近和身体接触倾向，加速了从独居相到群居相的行为转变。这些结果强调了 4VA 在飞蝗行为相转变中的关键作用。此外，这项研究为促进蝗群形成的行为可塑性机制提供了有价值的见解，并表明 4VA 在飞蝗控制中的应用潜力。
