Nanoengineered particulate coatings (NPCs) comprise a multiplicity of particulate hosts that are infused with a nanophase comprising a surfactant and at least one guest. The particulate hosts can be clay particles, the surfactant can be a cationic surfactant, and the guest can be an insect repellant. For example, montmorillonite particles infused with hexadecyl trimethyl ammonium bromide and garlic oil form NPCs that may be used to form an emulsion or suspension for spraying on citrus trees to repel Asian Citrus Psyllid.