| In this study, we used the Bemisia tabaci biotype B farming by cotton as material, determined the biological activity, field efficacy of the new type of insecticide Spirotetramat to the Bemisia tabaci biotype B, and on the basis, we study the biological parameters, the main body of nutrients and detoxification enzyme activities.of the Spirotetramat to the Bemisia tabaci biotype B, defined that the influence of the Spirotetramat to the virulence situation and biological parameters of the Bemisia tabaci biotype B. Evaluated the activity of Spirotetramat, provide technical reference for the field reasonable use of Spirotetramat and the whitefly control. The main conclusions are as follows:1 By using egg-dipping and leaf-dipping, we examined the toxicity of Spirotetramat and Imidacloprid to different instars nymphs of Bemisia tabaci biotype B. Results showed that Spirotetramat had highest toxicity to the 2nd instar larva, the LC50 was 4.0665 mg/L, that was 2.73 times to imidacloprid, the toxicity to the eggs and adults was low, and lower than Imidacloprid.2 Repellent effect was determined by spray with insect rearing in the cage, Spirotetramat had low repellent action to the adults after 4h, 24h, 48h. Repellent action is 25.19%~41.47% after 4h, best results appeared in 24 h, repellent action of 100 mg/L was 52%. Repellent action between 4h and 24h is or less. Compared with the control pesticide Imidacloprid, Spirotetramat had lower repellent action, repellent action is less effective.3 By using leaf-dipping feeding Bemisia tabaci biotype B different days, we examined the effect of Spirotetramat to the longevity, fecundity and eggs hatchability of Bemisia tabaci biotype B in the laboratory. Results showed that after feeding 2days, longevity of the Bemisia tabaci biotype B were 17.3±2.01 days deal with 12.5 mg/L Spirotetramat, that was significantly shorted compared with 0.2% Tween-80 treated (18.7±3.08 days); The fecundity deal with 12.5 mg/L Spirotetramat were 5, significantly reduced compared with 0.2% Tween-80 treated (183.5); The eggs hatching rate were 3.23% with 12.5 mg/L Spirotetramat, that was significantly inhibited to eggs hatching.4 We examined the effect of different concentrations of Spirotetramat for different time females lay eggs on the growth and development of the course and after the eggs develop into adult fecundity of female, Results showed that the longevity of female eggs to nymphs were some delay compared with the control, the longevity were 11.3±3.26 days deal with 50 mg/L Spirotetramat, that was significantly shorted 0.92±2.34days compared with 0.2% Tween-80 treated; the longevity of the Spirotetramat selected population was 10.4±2.34 days, that was not significantly compared with 0.2% Tween-80 treated; After the eggs develop into nymphs the longevity of nymphs was 10.6±2.29 days, that was significantly shorted 1.12±3.08 days compared with 0.2% Tween-80 treated; Other and Spirotetramat selected population were not significantly compared with 0.2% Tween-80 treated. After the nymphs develop into adults all treatments were not significantly compared with 0.2% Tween-80 treated.5 Determined the activity detoxification enzyme and nutrients of Bemisia tabaci biotype B deal with Spirotetramat, results showed that selected many populations in laboratory, the specific activities of CarE, AChE and GST were 49.9635 umol/mgpro·min 0.0186 mmol/mgpro·min and 1.3236 umol/mgpro·min. That was slightly higher compared with susceptible population that was not significantly; Determined the contents of lipids and total sugars after feeding leafs which dipped by spirotetramat, results showed that the lipids was significantly reduced after deal with Spirotetramat. the lipids were 35.39% 34.47% 34.54% respectively after 2days 4days and 6 days deal with Spirotetramat, that were 0.70 0.65 0.66 times compared with susceptible population, the lipids of Spirotetramat selected population was 34.22%, 0.66 times compared with susceptible population, that was significantly. Total sugars was significantly reduced after 2 days deal with Spirotetramat, the total sugars were 8.62%, and 60.36% of the susceptible population, but the total sugars was significantly rised, significantly compared with susceptible population.6 Field experiments used Imidacloprid and Avermectins as the contrast. Results showed that Spirotetramat had good effect, the highest control efficiency of 100 g a.i/ha was 89.70%, was higher than 76.90% and 81.4% of the Imidacloprid and Avermectins, and the efficacy could sustain for a long time. |
PDF Full Text Request