Dominion 2L is a systemic insecticide which is 21.4% Imidacloprid. This product is great for treating Cepe Myrtle Bark Scale. Simply mix 0.4 oz of Dominion per ft of tree height in a couple of gallons of water and pour at the base. This will give you season long control of Bark Scale. The Black Suity Mold on the trees will slowly go away after the insects are controlled.