Abstract:

The toxicity and relative enzymes activity were studied based on the resistance of three different extracts of walnut green husk against Tetranychus cinnabarinus in the laboratory. The mortality from petroleum ether extract of walnut green husk was 83.44% at 24 h after treatment，which showed that the acaricidal activity of the petroleum ether extract was significantly higher than the chloroform and methanol ones in the concentration of 1 mg·mL (P<0.05). After parted and purified by extracting and chromatography，the acaricidal activity of petroleum ether part of the petroleum ether extract was significantly greater (P<0.05) than the methanol one’s in the concentration of 1 mg·mL and its mortality to female adults of T. cinnabarinus has reached 84.39% at 24 h after treatment. Then，the petroleum ether part was purified by chromatography，there were 19 parts gained in which the toxicity of 4 parts (6th，7th，13th，17th parts) were stronger than the others，their mortalities have been all above 60%. The 6th part’s purity has been above 90% by HPLC. After detailed gradient detection，the extraction rate and the mortality were 6.34% and 98.45%，respectively，in the concentration of 10 mg·mL^-1. The activity of AchE and Na⁺，K⁺ ATPase in T. cinnabarinuswere assayed by colorimetric method after application of the 6th part’s purity. In the concentration of 10 mg·mL^-1，the two enzymes’ activities lower than CK，the activities of AchE and Na⁺，K⁺ATPase were 0.47 and 0.62 times as control at 8 h after treatment.

Key words: Tetranychus cinnabarinus, Juglans regia, acetylcholinesterase, Na⁺, K⁺ATPase