ACTA ZOOLOGICA BULGARICA, cilt.69, ss.193-200, 2017 (SCI-Expanded)
This study describes the principal and accessory salivary glands of adults of Piezodorus lituratus (Fabricius, 1794) (Heteroptera: Pentatomidae) by using light, scanning and transmission electron microscopy. Light and scanning electron microscopy images demonstrate that a pair of salivary systems of P. lituratus, each containing two distinct units (principal and accessory salivary glands) with different sizes. The principal salivary glands are bi-lobed, with a short anterior and long posterior lobes. In P. lituratus, the accessory salivary glands are short, S-shaped and with tubular structure. Their outer surface is attached to the trachea and the tracheoles. Transmission electron microscopy examinations showed that the principal salivary gland units consist of a monolayer of epithelium cells with apical microvilli surrounding a large central lumen. Their cells have secretory granules, a well-developed nucleus and granulated endoplasmic reticulum in the cytoplasm. The accessory salivary gland cells are cuboidal in shape with apical microvilli surrounding a narrow lumen.