Ultrastructure of the midgut in Heteroptera (Hemiptera) with different feeding habits

Abstract

Heteroptera have diverse feeding habits with phytophagous, zoophagous, and haematophagous species. This dietary diversity associated with the monophyly of Heteroptera makes these insects a good object for comparative studies of the digestive tract. This work compares the ultrastructure of the middle midgut region in the phytophagous Coptosoma scutellatum (Plataspidae), Graphosoma lineatum (Pentatomidae), Kleidocerys resedae (Lygaeidae), and zoophagous Rhynocoris iracundus (Reduviidae), Nabis rugosus (Nabidae), and Himacerus apterus (Nabidae), to verify if diet affects midgut cells in phylogenetically related insects. The middle region of the midgut was used for comparison because it is the main site for digestion and absorption of the midgut. The digestive cell ultrastructure was similar in the six species, with features of secretory, absorptive, transport, storage, and excretory cells, suggesting a stronger correlation of middle digestive cell ultrastructure with the phylogeny of these species than with the different heteropteran feeding habits.

Ultrastructural Characterization of Salivary Glands, Alimentary Canal and Malpighian Tubules of the Red Shield Bug Carpocoris mediterraneus Tamanini, 1958 (Heteroptera, Pentatomidae)

“…The midgut cells of C. mediterraneus have a well-developed nucleus with decondensed chromatin and nucleolus, which are the common features of these cells in insects (Billingsley & Lehane, 1996) that occur in cells with high metabolic activity (Alberts et al, 2014). A similar situation was noted in Coptosoma scutellatum (Geoffroy, 1785) (Plataspidae), Graphosoma lineatum (Linnaeus, 1758) (Pentatomidae), Rhynocoris iracundus (Linnaeus, 1758) (Reduviidae), N. rugosus (Linnaeus, 1758) (Nabidae), and H. ( Himacerus ) apterus (Fabricius, 1798) (Nabidae) by Santos et al (2017). Nevertheless, the nuclei of digestive cells occur in Kleidocerys resedae (Panzer, 1797) (Lygaeidae) with some electron-dense patches (Santos et al, 2017).…”

“…A similar situation was noted in Coptosoma scutellatum (Geoffroy, 1785) (Plataspidae), Graphosoma lineatum (Linnaeus, 1758) (Pentatomidae), Rhynocoris iracundus (Linnaeus, 1758) (Reduviidae), N. rugosus (Linnaeus, 1758) (Nabidae), and H. ( Himacerus ) apterus (Fabricius, 1798) (Nabidae) by Santos et al (2017). Nevertheless, the nuclei of digestive cells occur in Kleidocerys resedae (Panzer, 1797) (Lygaeidae) with some electron-dense patches (Santos et al, 2017).…”

“…Heteroptera have different dietary habits with phytophagous, zoophagous, and hematophagous species, and this dietary diversity associated with the monophyly of Heteroptera makes these insects a good object for digestive system studies (Santos et al, 2017). For zoophagy and phytophagy, Heteroptera saliva compounds contribute to the understanding of the extra-oral digestion of these insects (Baptist, 1941; Ammar, 1986; Nunes & Camargo-Mathias, 2006; Anhê et al, 2021; Carvalho et al, 2021; Özyurt Koçakoğlu, 2021).…”

The Spherocrystals in the Tubule Epithelial Cells and Ultrastructure of the Malpighian Tubules of Adult Isophya nervosa (Orthoptera, Tettigoniidae)

“…These spherocrystals, which are commonly called as laminate spheres, spherites or mineral concretions, are generally supposed to serve as a form of storage excretion [12]. These spherocrystrals have a concentric content reported in cells of many insect internal systems [13,43,44]. They are always associated with a specific cell type.…”

Hexapod Assassins’ Potion: Venom Composition and Bioactivity from the Eurasian Assassin Bug Rhynocoris iracundus

“…Kissing bugs (Heteroptera: Triatominae) are hematophagous species specialized on blood meals and their saliva possess local anesthetic effects enabling stealth feeding [19,20]. While phytophagous hemipteran have specialized to feed on various plant tissues (e.g., vascular fluids, cell contents, and seeds) [21,22], assassin bugs (Heteroptera: Reduviidae) are zoophagous and use their venom to paralyze and liquefy their invertebrate prey [23]. Their venom can also have severe effects on vertebrates, including pain, muscle paralysis, hemorrhage, and even death of mice due to respiratory paralysis [24,25].…”