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Objective To investigate the common-toxicity of the mixture of Cynanchum komarovii Al.and Sophora alopecuroides L.against Plutella xylostella L.Method The dipping method was adopted to measure the activities of ethanol extracts from C.komarovii and S.alopecuroides and their mixture against Plutella xylostella L.,and the common-toxicity of the mixture was evaluated by the methods of Bliss and Sun,respectively.Result There is significant synergism between the ethanol extracts of C.komarovii and S.alopecuroides.The co-toxicity coefficient (CTC) is 248.30 under the dry powder mass ratio of 2∶ 1.The mixture exhibits significant contact toxicity against the 3rd instar larvae of P.xylostella with the mortality rate of 100% under the concentration of 20.00 mg/mL.The LC50 of the mixture is 2.074 7 mg/mL,which is much lower than that of C.komarovii (LC50=4.30 mg/mL) and S.alopecuroides (LC50=8.51 mg/mL).Conclusion There is synergism between C.komarovii and S.alopecuroides ethanol extracts.
Objective To investigate the common-toxicity of the mixture of Cynanchum komarovii Al.and Sophora alopecuroides L. against Plutella xylostella L. Method of the dipping method was adopted to measure the activities of ethanol extracts from C.komarovii and S.alopecuroides and their mixture against Plutella xylostella L., and the common-toxicity of the mixture was evaluated by the methods of Bliss and Sun, respectively. Result There is significant synergism between the ethanol extracts of C. komarovii and S.alopecuroides. The co-toxicity coefficient (CTC ) 248.30 under the dry powder mass ratio of 2: 1. The mixture exhibits significant contact toxicity against the 3rd instar larvae of P. xylostella with the mortality rate of 100% under the concentration of 20.00 mg / mL. LC50 of the mixture is 2.074 7 mg / mL, which is much lower than that of C. komarovii (LC50 = 4.30 mg / mL) and S.alopecuroides (LC50 = 8.51 mg / mL) .Conclusion There is synergism between C.komarovii and S.alopecuroides ethanol extracts.