麦长管蚜有翅型与无翅型外部形态比较研究

本研究结合体式显微镜和扫描电镜,对有翅型与无翅型麦长管蚜各龄期的外部形态进行详细测量和系统观察。结果表明:1)麦长管蚜1、2龄若蚜外部形态无明显差别,触角均为5节;2)3龄有翅若蚜中胸发达,可见初生翅芽,至成虫期发育为完整的翅;3龄无翅若蚜中胸结构简单,未见翅芽,3龄至成蚜触角均为6节;3)1龄若蚜尾片呈瘤状,着生2根刚毛;2、3、4龄若蚜尾片呈圆锥形;有翅成蚜尾片呈长锥形,无翅成蚜呈长舌状,2龄若蚜至成蚜尾片均着生6根以上刚毛。本文首次探讨了麦长管蚜有翅型与无翅型成、若蚜外部形态的差异,并分析了其与麦长管蚜的生活史、迁移特性等特征之间的关系,以期为麦长管蚜分化的相关机理研究提供参考。

Morphological examination of winged and wingless forms of the grain aphid Sitobion miscanthi

The external morphology of winged and wingless forms of the grain aphidSitobion miscanthi was studied by using stereo microscope and scanning electron microscopy. The results showed that: 1) There were no obvious external differences between the 1st and 2nd instar nymphs. The antennae of both instars had five segments. 2) The middle thorax of the winged nymph since the 3rd instar was greatly enlarged and the wing buds could not be identified until integral wing developed in winged aphid adults. However, the 3rd instar nymphs without wing buds became wingless adults. The antennae consisted of six segments from 3rd instar stage to adult. 3) The cauda of the 1st instar nymphs were tuberculiform shaped, and armed with two acicular setae. It became conical shaped among 2nd, 3rd and 4th instar stages, and then was enlarged into long taper or long tongue shaped in the winged or wingless adults, respectively. Additionally, more than 6 setae were present from 2nd instar stage. The differences in the morphology of winged and wingless forms of S.miscanthi were compared and the relationship with their life history and migration characteristics were discussed, which would provide theoretical basis for the study of the wing dimorphism of aphids.