Urbanek Aleksandra, Szadziewski Ryszard, Giłka Wojciech
Department of Invertebrate Zoology and Parasitology, University of Gdańsk, ul. Wita Stwosza 59, 80-308 Gdańsk, Poland.
Department of Invertebrate Zoology and Parasitology, University of Gdańsk, ul. Wita Stwosza 59, 80-308 Gdańsk, Poland.
Arthropod Struct Dev. 2015 Jan;44(1):10-20. doi: 10.1016/j.asd.2014.10.004. Epub 2014 Nov 1.
The ultrastructure of the strong mediodorsal setae in terrestrial stage IV larvae of Atrichopogon (Meloehelea) oedemerarum and A. (M.) meloesugans was examined using light, scanning and transmission electron microscopy. Serrated setae placed on prominent processes are distributed in pairs on all thoracic and abdominal segments. Setae are innervated by a single dendrite and their surface has no pores. The trichogen cell is not retracted from the setal lumen on completion of the hair-forming process but fills the mediodorsal seta also when the larval cuticle is fully sclerotised. Such a phenomenon was previously reported in terrestrial larvae of the genus Forcipomyia. We suggest that the mediodorsal setae described in Atrichopogon are plesiotypic mechanoreceptors for the subfamily Forcipomyiinae. They are preserved in the truly terrestrial larvae of Atrichopogon, but modified to secretory setae in the genus Forcipomyia. Both genera bearing distinct mediodorsal setae have developed functional tracheal gills, unknown in other biting midges.
利用光学显微镜、扫描电子显微镜和透射电子显微镜，对肿腿鬃蠓（Meloehelea）肿腿亚种和甜鬃蠓（M.）甜亚种陆生IV龄幼虫的强中背刚毛超微结构进行了研究。锯齿状刚毛位于突出的突起上，成对分布于所有胸节和腹节。刚毛由单个树突支配，其表面无孔。在毛形成过程完成后，毛原细胞不会从刚毛腔缩回，而是在幼虫表皮完全硬化时也充满中背刚毛。这种现象先前在蠛蠓属的陆生幼虫中已有报道。我们认为，鬃蠓属中描述的中背刚毛是蠛蠓亚科的原始型机械感受器。它们在鬃蠓属真正的陆生幼虫中保留下来，但在蠛蠓属中演变成分泌刚毛。这两个具有明显中背刚毛的属都发育出了功能性气管鳃，这在其他咬蠓中是未知的。
