Bayer Natria Organic Exterminating Insecticide Made With Natural Pyrethrum 1L. Natria exterminating insecticide is a ready-to-use insecticide based on natural pyrethrum for the defence of floral and ornamental plants. The effectiveness of the active substance Pyrethrum insecticide is bolstered by Liquid formulation to base of vegetable oils that improve the distribution and the activity.