Radix puerariae peduncularis extractive and matrine-containing insecticidal composition and purpose thereof

The invention relates to an insecticidal composition which is characterized in that the active component in the insecticidal composition is a composition of a radix puerariae peduncularis extractive and matrine according to the weight ratio of (1 to 4) to (4 to 1). Furthermore, the insecticidal composition can be prepared into an insecticidal microemulsion. Compared with a single dosage, the insecticidal composition provided by the invention has good synergistic effect and has the synergistic coefficient being 130 or above. In addition, the microemulsion prepared by the invention is a novel water-based environment-friendly dosage form, is tiny in drug grains and easy in permeating body wall of an insect, and thus having better toxic killing effect to harmful insects. Since the used effective component is a plant medicament, the microemulsion provided by the invention is safe to non-target organisms and environment, is harmless to people and livestock, is suitable for being used for various crops and can effec