Chiang Min-Rou, Shelomi Matan
Department of Entomology, National Taiwan University, Taipei, Taiwan.
J Morphol. 2023 Apr;284(4):e21575. doi: 10.1002/jmor.21575.
During pupation, the tissues of holometabolous insects change in preparation for the adult lifestyles, although little literature exists examining this hidden process in detail. Using beetles as a model, we hypothesized that species where the adult and larva have the same diets will show less pronounced changes of the digestive tract during metamorphosis than species where the adults diets differ. We also wanted to observe these changes and document them at a level of detail missing from the current record. We compared the structure of the digestive tracts of scarab beetles Oryctes rhinoceros, Thaumastopeus shangaicus, and Protaetia spp. (Coleoptera: Scarabaeidae)-where the larvae eat wood, soil, or compost while the adults feed on soft plant matter, tree sap, and rotting fruits-with the tortoise beetle, Cassida circumdata (Coleoptera: Chrysomelidae), which feeds on leaves as both larva and adult. In the scarab beetles we observed considerable changes in the digestive tracts during the pupal stage, which we could divide into distinct stages, while in the leaf beetle pupae, the gut did not change. This information can provide new insight into metamorphosis, and the illustrations of what occurs during pupation are novel contributions to this field that will facilitate future work.
在化蛹期间，全变态昆虫的组织会发生变化，为成虫的生活方式做准备，尽管很少有文献详细研究这一隐藏过程。以甲虫为模型，我们推测成虫和幼虫食性相同的物种在变态过程中消化道的变化不如成虫食性不同的物种明显。我们还想观察这些变化，并以目前记录中所缺少的详细程度记录下来。我们比较了金龟子甲虫（犀金龟、尚氏犀金龟和丽金龟属，鞘翅目：金龟科）的消化道结构，这些甲虫的幼虫以木材、土壤或堆肥为食，而成虫以柔软的植物物质、树液和腐烂的水果为食，同时还比较了龟甲虫（环纹龟甲，鞘翅目：叶甲科）的消化道结构，其幼虫和成虫均以叶片为食。在金龟子甲虫中，我们观察到蛹期消化道有显著变化，这些变化可分为不同阶段，而在叶甲蛹中，肠道没有变化。这些信息可为变态研究提供新的见解，化蛹过程的图示是该领域的新贡献，将有助于未来的研究工作。
