Abstract: This invention provides for a solid, particulate insecticidal formulation in the form of a granule, a bait or a tablet for mechanical incorporation into or onto soil comprising a volatile insecticidal active ingredient that is microencapsulated and combined with a bulking agent and a disintegrating agent. The solid particulate formulation is characterized in that the volatile insecticide is selected from insecticidal active ingredients having: (a) a vapour pressure at 25° C. in the range from about 1 mPa to about 1,000 mPa; and (b) a water solubility at 25° C. less than about 100 mg/Litre.