不同化学药剂LC50胁迫对西花蓟马能源物质的影响

用毒死蜱、吡虫啉和噻嗪酮三种药剂LC_(50)胁迫2,4,6及8h后,测定西花蓟马可溶性糖、可溶性蛋白质及脂肪等3种能源物质的含量,并计算其致死作用下蓟马对不同能源物质的利用率.结果表明,不同药剂LC_(50)胁迫下,3种能源物质含量具有不同的波动,毒死蜱胁迫8h后,蓟马对可溶性糖、可溶性蛋白质及脂肪的消耗最多,其成虫含量分别降至5.47,15.25和11.66μg/头,若虫降至3.94,12.54和7.29μg/头;噻嗪酮胁迫8h后,消耗最少,成虫分别降至5.64,16.32和11.63μg/头,若虫降至4.05,12.73和7.39μg/头.同一药剂致死下,成虫及若虫对3种能源物质的利用率均为可溶性糖可溶性蛋白质脂肪;不同药剂致死下的相同能源物质,两者对可溶性糖和可溶性蛋白质的利用率均在毒死蜱作用下最高,噻嗪酮作用下最低,但其对脂肪的利用率在不同药剂之间均无显著差异.另外,相同药剂作用下,蓟马成虫对相同能源物质的利用率均显著高于若虫.

The effect of different pesticide exposure at median lethal concentration on the accumulation of energy sources in Frankliniella occidentalis

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 µg/insect in the thrips adult under natural condition, while 5.23, 14.59 and 8.28 µg/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 11.66µg/insect in adult, while they were 3.94, 12.54 and 7.29µg/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 11.63µg/insect in adult, 4.05, 12.73 and 7.39µg/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.