Triboelectric Charging During Insect Walking on Leaves: A Potential Tool for Sensing Plant-Insect Interactions

Plant-insect interactions are crucial for most ecosystems, and they are still not fully understood. Detecting and monitoring interactions of insects with plants could enable tools to observe pollination and circumvent potential damage to crop plants by pests. Sensorized artificial traps have made significant advances in monitoring pests in crop fields. Nevertheless, a direct measurement from the leaf level could further improve the resolution of such technologies. Here, we explore the opportunity to use the plant leaf itself as a biohybrid sensor for plant-insect interactions. Instead of measuring electrophysiological signals, we investigate the spontaneous charging of a Nerium oleander leaf surface during walking of Halyomorpha halys (better known as Asian stink bug) by contact or triboelectrification using high-resolution current recordings and the ion-conductive leaf tissue as a measurement electrode. Our results suggest that the insect’s walking and take-off from the leaf surface produce characteristic static surface charges potentially due to contact/triboelectrification that are electrostatically induced into the cellular tissue. Although further investigations are required to understand the phenomenon and its capabilities, it suggests that the leaf could be directly used as a sensor for insect-leaf interactions. This could be a tool to investigate insect-plant interactions under controlled laboratory conditions and may, in the future, benefit technologies like smart and precision agriculture and even measuring interactions of robotic insects with plants on the leaf level by tuning the triboelectric signals.