The invention discloses a preparation method of a
pesticide composition for killing cotton bollworms. The preparation method comprises the following steps: 1) preparing raw materials; 2) adding waterto decoct
semen hydnocarpi, fructus ulmi and cortex pseudolaricis twice, obtaining a
pesticide liquid for later use; 3) adding water to decoct
rhizome of canereed spiralflag, herba houttuyniae, flowerbelge, salix magnifica, radix curcumae and
iris tectorum twice, filtering, concentrating a filtrate to the
relative density of 1.15; 4) combining
pesticide liquid; 5) regulating the pH value of a solution; 6) performing
filtration, filling, and sterilization to obtain the pesticide composition. The pesticide composition kills the cotton bollworms in a targeted manner, is good in safety and biological degradation, is
pollution-free, has no pungent smell, no environmental toxic effect and no residue in an animal, does not destroy the ecological balance, has low effects on the growing environmentof a
crop, is relatively good in permeability and wettability, kills the
central nervous system of an
insect, inhibits the formation and development of a worm egg, does not cause
drug resistance easily, is good in fast-acting property, and is suitable for extensive popularization and application in the field of
pest control.