摘要
小地老虎Agrotis ypsilon (Rottemberg)幼虫表皮,在透射电镜下观察,上表皮外层是电子密度很高的一薄层,内层较厚,但电子密度不如外层,有时可见到很多蜡道。5龄幼虫蜕皮进入6龄前,已经形成4层原表皮,脱皮以后,以每6小时沉积一层的速率增加,即每日增加4层,至末龄幼虫老熟时,约有60多层。每个片层的两侧是平行纤丝,中间是弧形纤丝。在沉积片层时,几丁质以颗粒形式垂直向外分泌,逐渐形成弯曲的纤丝,最终成为抛物线形,各片层之间是间断的,片层内部是连续的,在扫描电镜下并可看到分离的薄层。大地老虎A.tokionis Butler幼虫表皮在偏光镜下,呈明暗相间的片层。原表皮中的孔道呈新月形管状,早期可见到管道微丝。在具有泡状物的原表皮内,孔道有较厚的管壁,并有分支。
The fine structures of larval cuticles of Agrotis ypsilon (Rottemberg) and Agrotis tofyonir Bulter were studied with electron microscope and compared. The result reveals that similarity prevails in these two species and their characteristics may be summarized as follows;1. The epicuticle contains two layers: a thin outer layer with high electron density and a thicker inner layer about 0.4 to 0.5 μm.2. The endocuticle consists of 60 lamellae (10-20 μm) in the last instar larvae, which show alternative succession of bright and dark layers under polarization microscope. These layers are seen as separable lamellate structure in the scanning electromicrogram3. The newly secreted endocuticle contains fine granules and chitinous filaments which are perpendicular to the epidermal cells at first and then gradually change in inclination to form a parabolic pattern.4. Before ecdysis 4 lamellae of new procuticle appear under the old cuticle, the deposition of procuticle continues after moulting and a daily increase of 4 lamellae can be discernible. 10, 16, 26, 40, 50 and 60 lamellae can be found in the cuticles of larvae from the first to the sixth (last) instars respectively. The increase of lamellae may be inhibited by treatment with precocene.5. The pore canal leading from epidermis to epicuticle consists both small canal and tihin element, but variation may be present in the shape aad component.
出处
《昆虫学报》
CAS
CSCD
北大核心
1990年第3期309-313,共5页
Acta Entomologica Sinica
基金
国家自然科学基金
关键词
地老虎
表皮
超微结构
cutworm--cuticle--tine structure
