4种生物农药对刘氏短须螨的毒力及苦参碱对相关酶活性的影响

Toxicity of four biological agents to Brevipalpus lewisi Mcgregor and the effect of matrine on the related enzyme activities of the mite

刘氏短须螨Brevipalpus lewisi Mcgregor是近年发现危害水杉的害螨。室内条件下采用玻片浸渍法测定了苦参碱、印楝素、阿维菌素和苏云金杆菌(Bt)4种生物药剂对刘氏短须螨成螨的毒力;采用生化方法测定了取食喷施苦参碱的水杉叶片后刘氏短须螨的过氧化物酶(POD)、谷胱甘肽-S-转移酶(GSTs)和乙酰胆碱酯酶(Ach E)的活性。结果显示:4种生物药剂对刘氏短须螨均具毒杀作用,校正死亡率随着浓度的增加而升高。其中,印楝素对刘氏短须螨的毒力最高,LC50达到5.36 mg/L;其次为苦参碱,LC50为7.18mg/L;阿维菌素和Bt相对较低,LC50分别为20.18 mg/L和20.69 mg/L。取食苦参碱处理的叶片,刘氏短须螨成螨体内的过氧化物酶、谷胱甘肽-S-转移酶和乙酰胆碱酯酶活性均产生不同程度的诱导效应。与对照组相比,螨体内乙酰胆碱酯酶和过氧化物酶活性显著增强;谷胱甘肽-S-转移酶活性呈上升趋势,但差异不显著。

Brevipalpus lewisi w as a pest new ly found on Metasequoia glyptostroboides in recent years.Toxicity of matrine,nimbin,avermectin and Bacillus thuringiensis（ Bt） to adults of B. lewisi w as evaluated by slide-dip immersion method and the influence of matrine on the related enzymes of the mite w as also detected in the laboratory. The results showed that among the four agents,nimbin had the highest toxicity and the LC50 to the adults was 5. 36 mg / L,followed by matrine with an LC50 of 7. 18 mg / L,avermectin with an LC50 of 20. 18 mg / L and Bt with an LC50 of 20. 69 mg / L. The activities of peroxidase（ POD）,acetylcholinesterase（ Ach E） were significantly higher than those in the control and the activity of glutathione-S-transferase（ GSTs） showed a rising trend,but the difference was not significant.