›› 2017, Vol. 60 ›› Issue (7): 835-841.doi: 10.16380/j.kcxb.2017.07.012

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小菜蛾外颚叶链锁形成喙管结构的观察与分析

谢佼昕1, 吴兰军1, 孙学俊1,2, 闫喜中1,*, 郝赤1,*   

  1. (1. 山西农业大学农学院, 山西太谷 030801; 2. Department of Experimental Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G1Z2, Canada)
  • 出版日期:2017-07-20 发布日期:2017-07-20

Structural observation and analysis of the proboscis formed by the linkage of the galeae in Plutella xylostella (Lepidoptera: Plutellidae)

XIE Jiao-Xin1, WU Lan-Jun1, SUN Xue-Jun1,2, YAN Xi-Zhong1,*, HAO Chi1,*   

  1. (1. Agricultural College, Shanxi Agricultural University, Taigu, Shanxi 030801, China; 2. Department of Experimental Oncology, University of Alberta, Cross Cancer Institute, Edmonton, Alberta T6G1Z2, Canada)
  • Online:2017-07-20 Published:2017-07-20

摘要: 【目的】了解小菜蛾Plutella xylostella两根外颚叶是如何通过其背部和腹部的链锁结构形成喙管的。【方法】利用光学显微镜观察小菜蛾口器特征,扫描电子显微镜观察喙管的背、腹部以及内侧的超微结构。【结果】小菜蛾的口器由一对下唇须和位于其中间的喙管组成,喙管由两根延长的外颚叶链锁形成。喙管背部的链锁结构通过两外颚叶的柳叶板交互重叠形成。每个柳叶板有上、下两部分,通常上柳叶板比下柳叶板小,但喙管顶端部位的下柳叶板消失,上柳叶板变大且在其外侧出现三角状凸起,在变大的柳叶板与外颚叶的连接处有孔状结构;喙管背部链锁方式主要是通过上、下两侧的柳叶板相互重叠紧密结合,靠近喙管顶端部位仅为上柳叶板重叠。喙管腹部链锁通过两外颚叶的齿状钩互锁结合,每个齿状钩由形状相似的上齿钩和下齿钩组成,从喙管基部到顶端,齿状钩长度逐渐增加,但是上齿钩长于下齿钩,两齿钩之间有间隙可供对侧齿状钩插入。【结论】小菜蛾外颚叶背、腹部链锁的结构与链锁方式具有特异性,可能与喙管卷曲和伸展时的运动方式不同有关。在喙管顶端,背侧链锁结构与外颚叶之间的孔可能是食物进入喙管的部位。

关键词: 小菜蛾, 外颚叶, 喙管, 链锁;口器, 超微结构, 扫描电子显微镜, 光学显微镜

Abstract: 【Aim】 To learn how the proboscis of Plutella xylostella is formed by two galeae using the dorsal and ventral linkages. 【Methods】 The mouthpart characteristics of P. xylostella were observed under light microscope. The ultrastructure of the dorsal linkage, ventral linkage and food canal of proboscis were observed under scanning electron microscope. 【Results】 The mouthparts of P. xylostella consist of a pair of labial palpi, and a proboscis is located in the middle. The proboscis is linked by two extended galeae. The dorsal linkage of proboscis is formed by overlapping lance-shaped plates of galea. The dorsal linkage contains two parts, i.e., upper and lower lanceshaped plates. In the apical part of proboscis, the lower lance-shaped plates disappear slowly while the upper lance-shaped plates gradually become larger and a row of triangular process appears in the outside. There are also some pores between upper lance-shaped plates and galea. The dorsal linkage is affected by a series of overlapping distally directed upper and lower lanceshaped plates of cuticle. However, in the subapical part of proboscis, the linkage is formed by the overlapping of the upper lance-shaped plates. The ventral linkage is affected by a series of closely applied, curved, toothed hooks which lock into each other from the two sides. Each toothed hook contains upper branch and lower branch with similar shape, the former being longer than the latter. From the basal part to the apical part of the proboscis, the length of the toothed hook gradually increases. There is a gap between the two branches for the opposite side of the toothed hook inserted. 【Conclusion】 The difference in the structure and linking mode of the dorsal and ventral linkage of the proboscis of P. xylostella may be related to the movement mode of proboscis when it coils or stretches. In the apical part of proboscis, the pores between the dorsal linkage and galea may be the place where food can be sucked in.

Key words: Plutella xylostella, galeae, proboscis, linkage, mouthpart, ultrastructure, scanning electron microscope, light microscope