Various microencapsulated insecticide formulations for the control of pests such as aphids and beet army worm. These formulations exhibit excellent knockdown activity towards both chewing and non-chewing pests as LD50 values for toxicity in female rats in the range of about 2,500 mgKg&minus；1. Some of these formulations include a wall comprised of a polymer formed, for example, by an interfacial polycondensation of a water soluble monomer and a water insoluble monomer, which at least partially surround an organophosphate insecticide. In some aspects the organophosphate in the microcapsule is chlorpyrifos. The microcapsule have a diameter in the range of about 2 to about 25 micron and the wall has a thickness in the range of about 5 to about 25 nanometers.
