Stem Surface Microstructure and Plant-Insect Interactions: A Perspective.

Plant surfaces form a critical biomechanical and ecological interface between plants and insects. Beyond chemical cues and rewards, the physical micro- and nanostructure of stems can decisively shape insect attachment, locomotion, and visitation patterns. This perspective paper synthesizes a body of work centered on studies by Gorb, Gorb, and collaborators (2017-2024), together with the broader literature cited therein, to develop a framework for understanding stem surface-mediated plant-insect interactions. We integrate comparative, experimental, and biomechanical evidence demonstrating that epicuticular waxes, pubescence, epidermal cell geometry, and surface roughness act each and in combination as a mechanical filter for crawling insects, particularly ants. We propose a unifying conceptual model, in which plant stem surfaces function as scale-dependent mechanical barriers that modulate insect access, balancing ecological trade-offs between attraction and exclusion. The paper further highlights ecological and evolutionary implications as well as methodological advances and discusses opportunities for bioinspired applications.