Mimicking Natural Deterrent Strategies in Plants using Adhesive Spheres

With a continuous increase in world population and food production, chemical pesticide use is growing accordingly, yet unsustainably. As chemical pesticides are harmful to the environment and pests develop resistance, sustainable and effective pesticide alternatives are needed. Inspired by nature, we mimic one defense strategy of plants, glandular trichomes, to shift away from using chemical pesticides by moving towards a physical immobilization strategy via adhesive particles. Through a controlled oxidation of a biobased starting material, triglyceride oils, an adhesive material is created while monitoring the reactive intermediates. After being milled into particles, nanoindentation shows these particles to be adhesive even at low contact forces. A suspension of particles is then sprayed onto chrysanthemum leaves and found to be highly effective at immobilizing a target pest, thrips, \textit{Frankliniella occidentalis}. Typical of small arthropod pests, thrips cause crop damage predominantly through virus transfer, which is prevented by their immobilization. We show that through this scalable fabrication process, biosourced materials can be used to create an effective, sustainable physical pesticide.