Halyomorpha halys (St & aring;l, 1855) is an invasive pentatomid species causing considerable economic losses in agricultural systems. Despite the ecological importance of the metathoracic scent gland (MTG) in chemical defence and communication, detailed information on its morphology and secretion composition remains limited. In the present study, the MTG of adult males and females was examined using stereomicroscopy, light microscopy, scanning electron microscopy (SEM) and gas chromatography-mass spectrometry (GC-MS). The gland consisted of a single-lobed reservoir associated with paired lateral glands, ostiolar openings and a well-developed evaporatorium. Scanning electron microscopy revealed a porous band-like structure embedded within the reservoir wall and an evaporatory surface densely covered with mushroom-like cuticular bodies interconnected by trabeculae. A distinct channel-like structure extending from the ostiole was also observed. GC-MS analysis identified 10 compounds in males and 11 in females, with trans-2-decenoic acid as the predominant component in both sexes, whereas several minor constituents showed sex-associated variation. These findings provide a comprehensive morphological and chemical characterization of the MTG in H. halys, expanding current knowledge of scent gland organization in Pentatomidae and providing a morphological framework for future comparative and functional studies.
ABSTRACT In this study, the egg‐laying behaviour and chorionic morphology of the eggs of the backswimmer Notonecta viridis Delcourt, 1909 (Heteroptera: Notonectidae) were described in detail using stereo, light and electron microscopy. Female N. viridis lays its eggs individually, horizontally attached to the surface. Eggs are elliptical, approximately 1.65–1.8 mm long and 0.56–0.61 mm wide. Newly laid eggs are slightly transparent and pale yellow in colour. The lateral edge of the egg tip contains a horn‐like structure, the micropyle. The chorion is often thick and ruffled, decorated with disorganized polygonal patterns. Aeropyle holes are located between the polygonal structures. Polygonal patterns appear simplified at the adhesion surface and basal region. In cross‐sections, the egg chorion reaches a thickness of up to 19.7 μm at the tuberculated boundaries of the hexagons, while decreasing to 7.12 μm in thinner regions. Ultrastructural examination of the chorion in cross‐section reveals that the innermost layer consists of the endochorion, and the outermost layer consists of the globular exochorion. This study highlights the spawning behaviour and egg morphology of N. viridis , a vital component of aquatic ecosystems. Clearly defining the egg stage, a critical phase in insect development, is crucial for ensuring the species' survival and its role in the ecosystem.
ABSTRACT The order Xenarthra presents unique morphophysiological adaptations related to its specialized ecological niches. This study investigates the functional morphology and comparative myology of the thoracic limb in Cyclopes didactylus (silky anteater) and Tamandua tetradactyla (southern tamandua) to elucidate how muscle arrangements support digging and climbing activities. Two C. didactylus and four T. tetradactyla specimens were dissected following standard anatomical procedures. The results revealed that although both species share a similar muscular structure, C. didactylus exhibits marked muscle hypertrophy, particularly in the intrinsic muscles of the arm and forearm, reflecting its strictly arboreal lifestyle. Comparative dissections demonstrated that C. didactylus shares the characteristic continuity between the medial head of the triceps brachii muscle and the flexor digitorum profundus muscle, previously described for T. tetradactyla , thereby providing a modern comparative description of its forelimb musculature. This configuration, alongside the significant development of the M. brachioradialis and extensor muscles, enhances digit flexion and grip strength. We conclude that the observed myological variations represent specific ecomorphological specializations: while T. tetradactyla maintains a balance for terrestrial digging and climbing, C. didactylus presents a specialized apparatus for sustained suspension and locomotion in the canopy.
This study presents the first detailed morphological analysis of the male reproductive system of Chalcophora mariana (Linnaeus, 1758) using stereo microscopy, light microscopy, and scanning electron microscopy. The male reproductive system of C. mariana consists of a pair of testes, vas deferens, accessory glands, spermatophoral glands, and a single ejaculatory duct leading to the aedeagus. Each testis contains approximately 30 elongated follicles, while the vas deferens, located beneath the testes, transports mature sperm. The vas deferens connects directly to the ejaculatory duct, which is surrounded by a thick layer of muscle. The accessory glands are long, coiled tubes lined with a single layer of cylindrical cells. The heart-shaped spermatophoral glands open into the ejaculatory duct, which contains pseudostratified epithelium and muscle layer. The ejaculatory duct is connected to the aedeagus by striated muscle bundles. The study identified notable interspecific differences in the number and shape of testicular follicles and in the morphology of accessory glands when compared to other Coleoptera species. These findings provide important morphological data contributing to future comparative and phylogenetic studies on male reproductive structures in Coleoptera.
Features of the reproductive organs, such as the number of testicular follicles, testis colour and the morphology of the glands, can be used as systematic characters. For this purpose, this paper was the first description of the male reproductive system anatomy and histology of Hypera postica (Gyllenhal, 1813) (Coleoptera: Curculionidae), a harmful pest in alfalfa, using stereo, light and scanning electron microscopy. Results show that the male reproductive system consists of two testes, seminal vesicles, vasa deferentia, accessory glands, prostate glands, a ejaculatory duct and an aedeagus. Each testis contains about 12 testicular follicles, each containing four germ cell types: spermatogonia, spermatocytes, spermatids and spermatozoa. The testis opens into the vas deferens via the seminal vesicle. They are lined by a single layer of cylindrical epithelium containing mature sperm in the lumen. H. postica has two distinct pairs of glands: tubular accessory glands, surrounded by cylindrical epithelium with eosinophilic secretions and multi-lobed prostate glands, lined with cuboidal epithelium containing basophilic secretions. These findings not only provide a foundation for understanding the anatomy and histology of the male reproductive system of H. postica, but also offer insights into the evolutionary adaptations of Coleoptera, contributing to broader entomological and ecological studies.
