The burrower bug Scaptocoris castanea is an important soybean and pasture pest in Brazil, with an underground habit feeding directly on the sap of the roots. Underground habit hinders control and knowledge of the biology and physiology of this pest. This study describes the anatomy, histology, ultrastructure and symbionts of the midgut of S. castanea. The midgut of S. castanea is anatomically divided into five regions (ventricles). Ventricles 1–3 are similar between males and females, with cells specialized in digestion and absorption of nutrients, water transport and homeostasis. Ventricle 4 has squamous epithelium forming crypts and harboring bacteria in the lumen. Ventricle 5 of males is small with cells containing apical microvilli and broad basal folds with many openings for hemocoel, while in females, this region of the midgut is well developed and colonized by intracellular bacteria, characterizing bacteriocytes. The main bacteria are Gammaproteobacteria. The results show sexual dimorphism in ventricle 5 of the midgut of S. castanea, with formation of bacteriocytes in the females, while the other regions are involved in digestive processes in both sexes.

中文翻译：

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Scaptocoris castanea Perty 中肠细菌群落的形态和组成，1830（半翅目：Cydnidae）

掘地虫 Scaptocoris castanea 是巴西重要的大豆和牧草害虫，在地下习性直接以根汁为食。地下习性阻碍了对这种害虫的生物学和生理学的控制和了解。这项研究描述了 S. castanea 中肠的解剖结构、组织学、超微结构和共生体。S. castanea 的中肠在解剖学上分为五个区域（心室）。雄性和雌性脑室 1-3 相似，细胞专门负责营养物质的消化和吸收、水分运输和体内平衡。心室 4 具有形成隐窝的鳞状上皮并在腔内藏匿细菌。雄性的第 5 脑室很小，细胞含有顶端微绒毛和宽阔的基底皱襞，有许多血腔开口，而在雌性中，中肠的这个区域发育良好并被细胞内细菌定植，这是细菌细胞的特征。主要细菌是γ-变形菌。结果表明，S. castanea 中肠 5 脑室的性别二态性，在雌性中形成了细菌细胞，而其他区域则参与了两性的消化过程。