Action 505 is an insecticide which is a combination of two active ingredients, chlorpyrifos and cypermethrin. The former belongs to phosphorothioate group of organophosphorus pesticides and the later is a synthetic pyrethroid. Action 505 affects both the axonic and synaptic transmission of the nerve impulses in the insect nervous system. Action 505 is a broad spectrum contact and stomach poison, with fumigant action.