The experiment was conducted in laboratory by dip method, adult and 2nd instar of Frankliniella occidentalis were exposed to medial lethal doses of different pesticides of chlorpyrifos, imidacloprid and buprofezin at the following exposure times: 2, 4, 6, and 8 h, respectively before the content of energy sources in F. occidentalis were tested. Furthermore the utilization rate of energy source in F. occidentalis was calculated after the insects were exposed to each pesticide until dead. The results showed that the content of soluble sugar, soluble protein and lipid were 7.67, 18.44 and 12.44 ?g/insect in the thrips adult under natural condition, while 5.23, 14.59 and 8.28 ?g/insect in the 2nd instar, respectively. There were different variation on the content of the three kinds of energy sources with increase and decrease during the short pesticide exposure, and they decreased mostly after chlorpyrifos exposure for 8 h in the thrips, with the value of 5.47, 15.25 and 11.66?g/insect in adult, while they were 3.94, 12.54 and 7.29?g/insect in the 2nd instar. There was a least decrease of the three kinds of energy sources after buprofezin exposure for 8 h, with the value of 5.64, 16.32 and 11.63?g/insect in adult, 4.05, 12.73 and 7.39?g/insect in 2nd instar, respectively. Both of adult and 2nd instar performed similar utilization to different energy sources after each pesticide exposure until dead, there was significant difference in the utilization rate of the three kinds of energy sources with the consumption of soluble sugar>soluble protein>lipid. They also had similar utilization on the same energy source under different pesticide exposure until dead, both of them had the highest utilization rate on soluble sugar and soluble protein after chlorpyrifos exposure, followed imidacloprid, and buprofezin was last, while there was no significant difference in the utilization of lipid in both of the two stages of thrips after different pesticide exposure..Furthermore, adults always performed a higher utilization rate than 2nd instar on the same energy source after the same pesticide exposure.
