灭幼脲对粘虫围食膜的影响及与其病毒的联合毒力作用

Effect of Diflubenzuron on Peritrophic Membrane of Mythimna separata ( Walker) and Allied Toxicity Function of Diflubenzuron and Pseudaletia Nuclear Polyhedrosis Virus,PsNVP against M.separata

【目的】明确灭幼脲对粘虫中肠围食膜的影响以及与粘虫核多角体病毒的增效作用。【方法】应用电子扫描显微镜及生物测定的方法研究了粘虫Mythimna separata(Walker)正常围食膜和灭幼脲处理围食膜的表面形态结构以及灭幼脲和粘虫核多角体病毒对粘虫2龄以上幼虫的联合毒力作用。【结果】正常幼虫的围食膜富有弹性,表面光滑、无间隙;但经灭幼脲处理的幼虫围食膜明显变薄,表面粗糙,易产生裂隙;生物测定结果显示,灭幼脲与PsNVP的混剂对东方粘虫的各龄幼虫匀表现出不同程度的增效作用,对3~5龄幼虫增效作用比较明显,并降低了其半致死浓度,缩短了半致死时间。【结论】灭幼脲对粘虫围食膜结构具有一定破坏作用而且对其病毒的增效作用明显。

【Objective】The objective of this study was to dentify the effect of diflubenzuron on peritrophic membrane( PE) of Mythimna separata( Walker) and the allied toxicity function of Diflubenzuron and Pseudaletia Nuclear Polyhedrosis Virus,PsNVP against M. separata.【Method】By means of scanning electron microscopy( SEM) and bioassay,the normal and Diflubenzuron treated peritrophic membrane( PM) of M. Separate was studied and the allied toxicity function of Diflubenzuron and PsNVP against M. Separata was also carried out. 【Result】The results from SEM indicated that the normal PM suface was smooth without pores or slits but the treated PM had some slits. The results from bioassay showed that the combination of Diflubenzuron and PsNVP can increase larval mortality,reduce both the median survival time( LT50) and the median letal concentration( LC_(50)) of Diflubenzuron and PsNVP.【Conclusion】In conclusion Diflubenzuron can destroy the PE of the larvae of M. Separata,and the allied toxicity function of Diflubenzuron and PsNVP was enhanced.