双斑恩蚜小蜂寄生对烟粉虱体内保幼激素和20-羟基蜕皮酮含量的影响

用反相高效液相色谱法（RP-HPLC）测定了烟粉虱Bemisia tabaci体内保幼激素和20-羟基蜕皮酮的滴度。结果显示，被双斑恩蚜小蜂Encarsia bimaculata寄生的烟粉虱高龄若虫体内的保幼激素滴度显著高于（P<0.05）对照即未被寄生的高龄若虫，20-羟基蜕皮酮（20-E）滴度显著低于（P<0.05）对照，与未被寄生的低龄若虫滴度差异不显著，说明双斑恩蚜小蜂寄生后可以将烟粉虱高龄若虫的激素含量保持在低龄若虫的水平，从而调节烟粉虱高龄若虫的生长发育。烟粉虱伪蛹和成虫与对照体内保幼激素含量，烟粉虱伪蛹与对照之间20-E含量差异均不显著（P>0.05）。

Effects of endoparasitism by Encarsia bimaculata on the titers of juvenile hormones and 20-hydroxyecdysone in Bemisia tabaci nymphs

The juvenile hormones (JHs) and molting hormone 20-hydroxyecdysone (20-E) from Bemisia tabaci nymphs and adults un-parasitized or parasitized by Encarsia bimaculata  were measured with RP-HPLC. The results indicated that the parasitized older nymphs had significantly higher titer of JHs (P<0.05) but sign ificantly lower titer of 20-E (P<0.05) than those un-parasitized older nymphs (CK), which had similar titers of JHs and 20-E with the un-parasitized younger nymphs. This suggested that E. bimaculata could modulate its host metamorphosis hormone level, and prolong the nymph stage of its host. JH titers between adults,‘pupae' and CK, and 20-E titers between‘pupae' and CK of  B. tabaci, however, were not significantly different (P>0.05). 22Refs. In Chinese.