Investigation of the midgut structure and ultrastructure in Cimex lectularius and Cimex pipistrelli (Hemiptera: Cimicidae)

Abstract

Cimicidae are temporary ectoparasites, which means that they cannot obtain food continuously. Both Cimex species examined here, Cimex lectularius (Linnaeus 1758) and Cimex pipistrelli (Jenyns 1839), can feed on a non-natal host, C. lectularius from humans on bats, C. pipistrelli on humans, but never naturally. The midgut of C. lectularius and C. pipistrelli is composed of three distinct regions—the anterior midgut (AMG), which has a sack-like shape, the long tube-shaped middle midgut (MMG), and the posterior midgut (PMG). The different ultrastructures of the AMG, MMG, and PMG in both of the species examined suggest that these regions must fulfill different functions in the digestive system. Ultrastructural analysis showed that the AMG fulfills the role of storing food and synthesizing and secreting enzymes, while the MMG is the main organ for the synthesis of enzymes, secretion, and the storage of the reserve material. Additionally, both regions, the AMG and MMG, are involved in water absorption in the digestive system of both Cimex species. The PMG is the part of the midgut in which spherites accumulate. The results of our studies confirm the suggestion of former authors that the structure of the digestive tract of insects is not attributed solely to diet but to the basic adaptation of an ancestor.

Three-dimensional reconstruction of a whole insect reveals its phloem sap-sucking mechanism at nano-resolution

“…Food fluids in the anterior regions of the midgut are completely absorbed and transferred into the hemolymph and excreted through the Malpighian tubules back into the hindgut ( Ohbayashi et al, 2015 ). Other families of Heteroptera including herbivorous Cimicomoepha and Leptopodmorpha, predatory Nepomorpha and Gerrmorpha have continuous intestines showing no unique water-disposal mechanism ( Habibi et al, 2008 ; Nardi et al, 2019 ; Rost-Roszkowska et al, 2017 ). Their convoluted alimentary canals indicate osmotic water exchanges by juxtapositioning an anterior region of the midgut to the most posterior region as in N. lugens .…”

Comparison of different cytogenetic methods and tissue suitability for the study of chromosomes in Cimex lectularius (Heteroptera, Cimicidae)

“…The mitotic division of regenerative cells has not been observed even in larvae in this case, in which the cells are only differentiated. Recently, no mitotic divisions and differentiations of the regenerative cells were observed in midgut epithelium of two Cimex species, C. lectularius and C. pipistrelli (Rost-Roszkowska et al 2016).…”

Comparison of different cytogenetic methods and tissue suitability for the study of chromosomes in Cimex lectularius (Heteroptera, Cimicidae)

“…The mitotic division of regenerative cells has not been observed even in larvae in this case, in which the cells are only differentiated. Recently, no mitotic divisions and differentiations of the regenerative cells were observed in midgut epithelium of two Cimex species, Cimex lectularius and Cimex pipistrelli (Rost-Roszkowska et al 2016). …”