Fumigant toxicity of βasarone extracted from Acorus calamus against the adults and immature stages of itophilus zeamais.

Key Words：Acorus calamus， βasarone， Sitophilus zeamais， fumigant toxicity

Abstract：       The fumigant toxicity of β-asarone extracted from Acorus calamus against the adults and immature stages of Sitophilus zeamais Motschulsky were studied. The results showed that β-asarone had fumigant toxicity to all of the four stages of the insect. The fumigant has the most toxicity to the adult, followed to the egg, while the larva and pupa possessed a relatively high resistance to β-asarone. When the egg was treated with βasarone at 200 μL/L concentration for 120 hours, the mortality was 99.09%. β-asarone showed little fumigation activity to the larva and pupa. After being treated for 120 hours, the LC₅₀ for S. zeamais adult was 17.82 μL/L.