Abstract：
The treehoppers (Hemiptera, Membracidae) are known for possessing a large three-dimensional structure called a helmet. Although some ecological functions of the helmet have already been elucidated, the developmental mechanisms underlying the complex and diverse morphology of the helmet are still largely unknown. The process of helmet formation was first described in Antianthe expansa, which possesses a simple roof-shaped helmet. However, the developmental process in species with more complex helmet morphologies remains largely unexplored. Hence, in this study, we used Poppea capricornis, which possesses a more complex helmet structure than A. expansa, to investigate the helmet development using paraffin sections, micro-CT, and scanning electronic microscopy. Our focus was on the overall helmet developmental process common to both species and formation of structures unique to Poppea and its comparison to Antianthe. As a result, we discovered that miniature structures were also formed in Poppea, similar to Antianthe, during the helmet formation. Common structures that were shared between the two species were discernible at this stage. Additionally, we observed that suprahumeral horns and posterior horns, two morphological traits specific to the Poppea helmet that are apparently similar anatomically, are formed through two distinctly different developmental mechanisms. The suprahumeral horns appeared to be formed by utilizing the nymphal suprahumeral bud as a mold, while we could not detect any nymphal structures potentially used for a mold in the posterior horns formation. Our findings suggest that the helmet formation mechanisms of Antianthe and Poppea employ a common mechanism but form species-specific structures by multiple mechanisms.
摘要：
树蝇（半翅目，Membracidae）以拥有称为头盔的大型三维结构而闻名。虽然头盔的一些生态功能已经被阐明，头盔形态复杂多样的发育机制在很大程度上仍然未知。头盔的形成过程首先在Antiantheexpandsa中描述，它拥有一个简单的屋顶形头盔。然而,具有更复杂头盔形态的物种的发育过程仍未被探索。因此，在这项研究中，我们用的是罂粟花,比A.expansa拥有更复杂的头盔结构，使用石蜡切片研究头盔的发展，Micro-CT,和扫描电子显微镜。我们的重点是两种物种共同的头盔整体发育过程，以及Poppea特有的结构的形成及其与Antianthe的比较。因此,我们发现在Poppea中也形成了微型结构，类似于Antianthe,在头盔形成过程中。在这一阶段，这两个物种之间共有的共同结构是显而易见的。此外,我们观察到肱骨上角和后角，Poppea头盔特有的两个形态特征在解剖学上明显相似，是通过两种截然不同的发育机制形成的。肱骨上角似乎是通过利用若虫肱骨上芽作为模具形成的，虽然我们无法检测到任何可能用于后角形成霉菌的若虫结构。我们的发现表明，Antianthe和Poppea的头盔形成机制采用了共同的机制，但通过多种机制形成了特定物种的结构。
