管侧沟茧蜂的寄生对甜菜夜蛾幼虫取食和发育的影响

为了明确和评价管侧沟茧蜂的利用价值,采用寄生与未寄生对比的方法,研究了管侧沟茧蜂的寄生对甜菜夜蛾幼虫取食量和发育的影响。结果表明,被寄生的甜菜夜蛾1,2,3龄幼虫与未被寄生的同龄期幼虫取食量差异达极显著水平;被寄生的1,2,3龄幼虫分别比未被寄生的同龄期幼虫取食量减少75 01%,65 64%和57.45%。被寄生的1,2,3龄幼虫取食量间的差异达显著水平,被寄生的2,3龄幼虫与被寄生的1龄幼虫的取食量差异达极显著水平,即1龄<2龄<3龄。被寄生的3龄幼虫与未被寄生的发育历期差异达极显著水平。被寄生的2,3龄幼虫与被寄生的1龄发育历期差异达显著水平。被寄生的幼虫随发育历期的延长,其取食量和幼虫体重缓慢上升,被寄生的从第6d或第7d后取食量和幼虫体重缓慢下降。所有被寄生的幼虫均不能化蛹。该寄生蜂不仅能够有效地控制甜菜夜蛾当代危害,而且在很大程度上能够抑制甜菜夜蛾的种群数量。

Effects of Parasitism by Microplitis tuberculifer on Food Consumption and Development of Spodoptera exigua Larvae

Method for contrast of parasitized and unparasitized was used to clarify and evaluate value in use of Microplitis tuberculifer.Effects of parasitism by Microplitis tuberculifer on food consumption and development of Spodoptera exigua larvae were studied. The results showed that the extremely significant difference existed in the food consumption of the parasitized larvae and unparasitized larvae by M.tuberculifer, the food consumption of the 1st, 2nd, and 3rd instars of parasitized larvae was lower by 75.01%, 65.64% and 57.45% than that of the 1st, 2nd, and 3rd instars of unparasitized larvae. The siginificant difference exsits in the food consumption of the 1st, 2nd, and 3rd instars of parasitized larvae . The food consumption of the 2nd and 3rd instars of parasitized larvae was extremely-significantly higher than that of the first instar larvae. Significant difference was found in development duration of the 3rd instar of parasitized larvae and unparasitized larvae. Siginificant difference exsited between development duration of the 2nd and 3rd instars of parasitized larvae and that of the first instar of parasitized larvae. The food consumption and the weight of parasitized larvae slowly increased as the duration of development was longer. The food consumption and the weight of larvae slowly decreased 6 and 7 days after being parasitized. The parasitized larvae did not pupate. This parasitoid could control effectively current generation harm and population of S.exigua.