Anatomy and Histology of the Midgut of Atopozelus opsimus (Heteroptera: Reduviidae)

ABSTRACT Atopozelus opsimus Elkins, 1954 (Heteroptera: Reduviidae) preys on forest and agricultural pests but also feeds on extrafloral nectar; however, its alimentary canal is poorly understood. The aim was to describe the anatomy and histology of the A. opsimus midgut. The alimentary canal of female and male A. opsimus was dissected, examined, processed, and analysed using light microscopy, revealing three midgut ventricles (V1, V2 and V3) in the midgut with similar morphology in both male and female. The digestive epithelium of V1 and V2 has a well‐developed apical brush border, a nucleus rich in decondensed chromatin and evident nucleolus, cytoplasm with basophilic granules and the lumen with multiple layers of perimicrovillar membrane. In the ventricle V3, the columnar digestive cells have an apical short and irregular brush border closely associated with some profiles of microvillar membrane, the nucleus with decondensed chromatin and the cytoplasm rich in basophilic granules and clear vacuoles. The midgut features suggest potential different functions, with V1 and V2 possibly having functions of secretion and absorption, whereas V3 may play some role in absorption and storage.