In order to examine the effect of emamectin benzoate to Frankliniella occidentalis, the toxicity of this insecticide to the adult and 2nd instar of F. occidentalis were studied  by dip method in this paper. In addition,  the content of soluble protein, soluble sugar and lipid in F. occidentalis were also tested after these insects were exposed to medial lethal doses of emamectin benzoate for the following exposure times: 2, 4, 6, and 8 h. Furthermore the utilization rate of the energy source in F. occidentalis was calculated after the insects were exposed to emamectin benzoate until dead at the medial lethal doses. The results showed that emamectin benzoate had different toxicity to the adult and 2nd instar of F. occidentalis, and the medial lethal doses were 1.11 and 0.62 mg/L, respectively. With the extension of exposure time at medial lethal doses of emamectin benzoate, there was significant a increase or decrease on the content of soluble protein, soluble sugar and lipid in F. occidentalis adult, but no significant variation on their content in F. occidentalis nymph. When the F. occidentalis was dead under the medial lethal doses exposure, there was significant difference in the utilization rate of the three kinds of energy sources in F. occidentalis, the utilization was soluble sugar（74.12%）> soluble protein（58.10%）> lipid（42.13%）in adult, significantly higher than that in nymph at any kind of the three energy sources, and the utilization was soluble sugar（64.01%）> soluble protein（48.12%）> lipid（36.48%）in nymph. According to the results, we could conclude that the different variation and utilization of energy source between F. occidentalis adult and nymph under the exposure of emamectin benzoate, may have some relationship to their different tolerance to this insecticide.

Aphis glycines Matsumura is a major insect pest damaging Glycina max. In order to investigate the mechanism of insecticide induced resurgence of the A. glycines, the changes of soluble sugar, free amino acid, soluble protein and crude fat contents in the 1st instar, 3rd instar, 4th instar nymphs and adults of A. glycines treated with medial lethal doses of imidacloprid were compared. The results showed that the reserves of energy substances in nymphs and adults had different variation trends. Contents of soluble sugar and free amino acid in the wingless and winged adults treated with medial lethal doses of imidacloprid were significantly higher than those of untreated A. glycines; Crude fat content in wingless and winged adults was significantly higher than the control; The variation trends of soluble protein contents in the wingless and winged adults were similar to those of crude fat.]]>

0 (parental) and the F1 (first generation) green peach aphid Myzus persicae were investigated to provide a theoretical basis for proper usage of this insecticide. 【Method】 The sublethal concentrations of LC10 and LC25 were determined by the bioassay method of Potter spray tower. The agar was placed at the bottom of the glass dish, while leaf discs were placed with their adaxial surface downward onto agar. Fifteen adult aphids were transferred onto each leaf disc. Insecticide were sprayed to the leaf disc with aphids by using the Potter spray tower under seven concentrations. Mortality of the aphids was recorded 48 h later. LC10 and LC25 were estimated using POLO-Plus10.0 software. Sublethal effects of sulfoxaflor on the development and reproduction of the green peach aphid was evaluated by the method of establishing a life table. For the F0 aphid, sulfoxaflor was sprayed on the adult aphids at the concentrations of LC10 and LC25. After the application of the insecticide for 48 h, the adults were moved to fresh leaves without insecticide and reared separately until death. For the F1 aphid, sulfoxaflor was sprayed on the adult aphids at the concentrations of LC10 and LC25. After the application of insecticide for 48 h, the adults were moved to fresh leaves without insecticide. When the adult aphid produced nymphs for 24 h, one nymph was randomly selected and reared separately until death. The survival and reproduction of each aphid were recorded. The statistical differences of the development duration of nymphs, the adult longevity, the number of nymph per aphid and the life table parameters of F0 and F1 were analyzed using SPSS 16.0.【Result】 According to the bioassay, the LC10 and LC25 of sulfoxaflor on the green peach aphid after 48 h were 0.012 and 0.041 mg·L-1. Treatments with sublethal concentrations of sulfoxaflor significantly reduced the adult longevity, the number of nymph per aphid and the reproductive period of F0 and F1. The values reduced with the increase of the concentration of insecticide. After being exposed to the sublethal concentrations LC10 and LC25 of sulfoxaflor, for the F0 aphid, the average longevity of aphid adult was 20.89 and 15.47 d, respectively, shorter than that of control (25.41 d). The nymph number per aphid after treatment with LC10 and LC25 of sulfoxaflor was 56.51 and 27.33, respectively, significantly less than that of control (71.02), while the reproductive period was 20.74 and 14.37 d, respectively, significantly shorter than that of control (25.27 d). For the F1 aphid, the average longevity of adult was 14.80 and 9.76 d, the reproductive period was 12.03 and 8.59 d, the nymph number per aphid after treatment with sulfoxaflor at LC10 and LC25 was 46.20 and 28.23, respectively. Compared with the control, treatment with sulfoxaflor at LC10 significantly extended the development duration of 1st instar nymph (1.73 and 2.21 d), while treatment with sulfoxaflor at LC25 significantly extended the development duration of 2nd instar nymph (1.43 and 1.58 d). However, there was no significantly difference in the other instar development duration and the total nymph period. Life table analysis showed that the net reproductive rate R0 was decreased significantly after treatment with sulfoxaflor at LC10 and LC25 with the values of 47.15, 24.55, respectively, compared with the control with a value of 64.47. 【Conclusion】Sublethal concentrations of sulfoxaflor have inhibitory effects on adult longevity and fecundity of the F0 and F1 M. persicae.]]>

To understand the biochemical difference between immigrant and non-immigrant Nilaparvata lugens offspring populations, we compared the changes in soluble sugar and crude fat contents in the 3rd and 5th instar nymphs and adults of the offsprings from immigrant and non-immigrant N. lugens, and free amino acid content in immigrant adults and their offspring adults on two rice varieties (TN1 and Xieyou 963) under insecticide stress. The biochemical substances were associated with insect origin (immigrant or non-immigrant), developmental stage, and insecticide type and insecticide concentration. Soluble sugar contents in the 3rd and 5th instar nymphs and adults of the offsprings that developed from the plants treated with insecticides and control (untreated) plants of TN1 for immigrant N. lugens were significantly higher than those for non-immigrant N. lugens. In contrast to soluble sugar content, crude fat content in the 3rd and 5th instar nymphs and adults of the offsprings that developed from the plants treated with insecticides and control plants of TN1 for immigrant N. lugens was significantly lower than that for non-immigrant N. lugens. For Xieyou 963, soluble sugar content in the 3rd and 5th instar nymphs showed the same tendency as TN1. Crude fat content in adults developed from control plants for immigrants was significantly higher than that for non-immigrant populations, and that in the 3rd and 5th instar nymphs did not show a significant difference between immigrant and non-immigrant N. lugens. Crude fat content in the 5th instar nymphs and adults which developed from the rice plants treated with insecticides for immigrant populations was significantly higher than that for non-immigrant. ANOVA results also demonstrated that as for changes in soluble sugar and crude fat contents, there were significant interactions between insect origin and insecticide type, insect origin and insecticide concentration, and insecticide type and insecticide concentration. For the two rice varieties, free amino acid content in immigrant adults was significantly lower than that in their offspring adults. Amino acid content in adults that developed from TN1 plants treated with triazophos was significantly higher than with deltamethrin and imidacloprid, while  in adults that developed from Xieyou 963 plants treated with deltamethrin and imidacloprid it was significantly higher than that with triazophos. The present findings have important significance for understanding the mechanism of insecticide-induced resurgence of the N. lugens.]]>

Nilaparvata lugens treated with sub-lethal doses of nitenpyram. The results indicated that the reserves of energy sources in nymphs and adults did have different variation trends. Soluble sugar contents in the 5th instar nymphs treated with LC10, LC30 stress in 12 h and 24 h and adults in 12 h stress were significantly higher than those 0f control; Glyceride contents in 5th instar nymphs and adults treated with LC10 stress were higher than those of control, but under 24 h stress, the glyceride content in the 5th instar nymphs was significantly lower than the control level; The variation trends of soluble protein contents in the 5th instar nymphs and adults were similar to that of free amino acid. The results suggested that under the control of sub-lethal doses of nitenpyram, the 5th instar nymphs and adults may have different coping mechanism and have important significance to understand the mechanism of sublethal doses of insecticide inducing resurgence of Nilaparvata lugens. ]]>