The present invention relates to a kind of plant protection composition or agricultural insecticides, including:The arbitrary blend of substance in the group including poly- (alkyl) guanidine, poly- (alkyl) biguanides, poly- guanine or Octenidine or the substance in the group.In a preferred embodiment, the substance being selected from the group for including poly- (alkyl) guanidine, poly- (alkyl) biguanides, poly- guanine or Octenidine, or the arbitrary blend of the substance in the group, to exist with the combination for active at least one other components of agricultural pest is shown.At least one activating agent for showing active at least one other components for agricultural pest and can representing known insecticide in the market.Another aspect of the present invention relates to a kind of methods protecting the plants from phytopathogenic invasion, and the method includes applying above-mentioned agricultural insecticide composition.
