Toxicity Test Of 20% Chlorantraniliprole SC Against Spodoptera Exigua (hübner) And Control Effect In Field

The common cutworm Spodoptera exigua (Hübner) is among the most damaging insect pest of vegetables ,and is famous for feeding on above 138 plant species from over 35 families worldwide. Searching new chemicals to control the pest is a large challenge for the reason of its resistance to nearly all kinds of chemicals against them.Beet armyworm, S. exigua (Hübner), was caught from the field .And it feed on laboratory over 20 generations. And the sensitivity of 3th larvae of S.exigua to Chlorantraniliprole was determined. Inside toxicity showed that LC50 values were 0.7475 mg/L and 0.2182 mg/L after 48 h and 72 h by toxicity tests .After 48 h the control is a little lower than the larval weight of S.exiguaafter Chlorantraniliprole treatment with the lowest concentration (0.0043 mg/L). However, as the increase of Chlorantraniliprole concentration , there comes obvious difference between treatments and control. This article has offered baseline for the susceptibility of S.exigua to Chlorantraniliprole and proved its higher toxicity to this kind of insect.In filed trials, the effects of three different insecticides were used for the control of S. exigua. The results showed that the control effect is from 72.5 % to100 % after 14 d with 1 000×20 % Chlorantraniliprole SC,68.8 % to 90 % after 14 d with 3 000×Avermectin and from 68.8 % to 80.4 % after 14 d with 1 000×Fenozide. The control effect of 1 000×20 % Chlorantraniliprole SC was 72.5 % ,while 3 000×Avermectin was 68.8 % and 1 000×Fenozide was 48.6 % after 1 d. The control effect of 20 % Chlorantraniliprole SC was both up to 100 % after 3 d and 7 d, while Avermectin was 90 % and Fenozide was 79.7 %.The result showed that 20 % Chlorantraniliprole SC and Avermectin have good efficiency, while Fenozide holds comparatively poor efficiency. 20 % Chlorantraniliprole SC has good effect on controlling S. exigua contract to comparing insectides. It persists over 14 days and possesses effect as well as safety.The author try to investigate indoor toxicity and field application of 20 % Chlorantraniliprole SC on S. exigua in order to measure its effect firstly and apply it more approperly.