The present invention is directed to an insecticidal water based suspension concentrate formulation comprising a water-soluble insecticide selected from the group consisting of N-cyanomethyl-4- (trifluoromethyl) nicotinamide and (EZ) - 1- (6-chloro-3-pyridylmethyl) - N-nitroimidazolidin-2-ylidineamine and at least one water-soluble salt selected from the group consisting of magnesium sulfate (hydrated and anhydrous forms) and sodium sulfate and wherein the water-soluble insecticide is present in an insecticidally effective amount and methods of use.