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, wherein the water-soluble insecticide is present in an insecticidally effective amount and methods of use.