甜菜夜蛾幼虫气门的超微结构观察

Ultr astructure of the spiracle of Spodoptera exigu Hubner

采用扫描电子显微镜对甜菜夜蛾5龄幼虫气门(spiracle)的超微结构进行了观察。结果表明,甜菜夜蛾的气门类型为内闭式气门(internat closing apparatus),外面观和内面观皆呈新月形或近圆形;气门的开闭结构主要由闭弓(closing bow)、闭带(closing valve)和闭肌(occluscle)3部分构成;气门的过滤结构(filter apparatus)外面观呈簇生状,分枝发达,内面观呈平行排列的树状,分枝不发达;气门外围体壁(integument)的表面具有馒头状(直径约1μm)的纹饰;蛹气门椭圆形,中央拱起,过滤结构分枝较少,气门外缘具砖形垫状结构。甜菜夜蛾气门的这种超微结构既具有其自身的生理意义,同时也可以作为其系统分类的参考依据。

The ultra structure of Spodoptera exigua Hübner spiracle was observed with scanning electron microscope（SEM）. The results show that the type of Spodoptera exigu spiracle is internal closing apparatus, the shapes of its outer view and inner view are similar to the beginning of moon or circular;the structure of switch is composed of three parts：closing bow,closing valve and occluscle; the outer view of filter apparatus closely resembles cluster, and has flourishing twigs, while the inner view is similar to parallel tree, and has thinly scattered twigs on it. There are many steamed bun ornamentation on body wall（about 1μm）;Pupas spiracle has arch-shaped elliptic spiracle, and filter apparatus of pupas spiracle presents little twigs compared with larvaew spiracle, and the outer view of the spiracle has rectangular block pad. These characteristics of ultra structure result from Spodoptera exigu adapting to circumstances for long time,at the same time they are useful to some extent for classification.