Scarabaeidae includes many phytophagous beetles, many of which are significant agricultural pests. Despite their importance, research on the reproductive tract of this family remains limited, and existing studies are mostly restricted to drawings and light microscopy. In fact, there is no study on this subject belonging to this genus. Therefore, in this study, we examined the histology and anatomy of the male reproductive tract in Oxythyrea funesta (Poda, 1761) using light and scanning electron microscopy. Our findings revealed that the reproductive system of O. funesta comprises two testes, vasa deferentia, seminal vesicles, accessory glands with reservoirs, an ejaculatory duct, and an aedeagus. Each testis lobe contains approximately 40 testicular follicles with growth, maturation, and differentiation zones. Spermatozoa are transported from the vas deferens to the seminal vesicles. The vas deferens and seminal vesicles are lined with a single layer of cuboidal epithelium and surrounded by a muscle layer. The accessory glands open into the ejaculatory duct via a large, pouch-like reservoir. This study provides a foundation for future comparative examination of the male reproductive tract in Scarabaeidae, including Oxythyrea. Additionally, it contributes to systematic studies by highlighting morphological similarities and differences when compared with other species.

This study aims to investigate the morphological structure of the midgut and hindgut of Eulasia arctos anatolica (Reitter, 1903) and to reveal, for the first time, the relationship between the pollen grains found in the digestive system and the feeding of E. arctos anatolica. According to the results obtained, the longest section of the digestive system of E. arctos anatolica, the midgut, has a single layer of columnar epithelial cells with a striated border and secretory vesicles, indicating apocrine secretion. Regenerative cells were found at the base of epithelial folds, and Scrophulariaceae pollen grains were present in the midgut lumen. The hindgut consists of the ileum, colon, and rectum. SEM and LM analyses showed that a cuticular intima, a single-layered cuboidal epithelium, and a muscle layer surround these sections. Spore-like granular structures and crystals were observed in the lumens of the ileum and colon. In the rectum, six rectal pads were identified, along with pollen grains from the Scrophulariaceae and Compositae families, as well as spore-like structures and crystals. The most important finding of the study is the direct observation of pollen grains in both the midgut and rectum lumens. This provides the first morphological evidence that E. arctos anatolica actively feeds on plants from the Scrophulariaceae and Compositae families. The results reveal not only the structural features of the digestive system but also functional adaptations to a diet based on pollen. Therefore, this study offers original contributions to the morphological and ecological understanding of the species’ feeding relationships.

Studying the morphology of the male reproductive system is crucial for understanding the reproductive biology of insects, particularly pest species. This study aimed to characterize the male reproductive system of the strawberry beetle pest Coraebus elatus (Fabricius, 1787) using light and scanning electron microscopies. The results revealed that each testis contains six testis follicles, each displaying distinct stages of differentiation of germ cells. Fully developed sperm pass through the vas deferentia, lined with a single-layer cuboidal epithelium and a muscle layer. While the wall of the tubular accessory glands is lined with a single-layered cuboidal epithelium, the wall of the bean-shaped spermatophoral glands is surrounded by a pseudostratified columnar epithelium. These glands open into the ejaculatory duct which is surrounded by a single-layer cylindrical epithelium and a muscle layer. This study provides valuable data that will serve as a foundation for future research on the morphology and systematic.

The female reproductive system, spermatheca, and eggs of the alfalfa weevil, Hypera postica, were analyzed using stereo, light, and scanning electron microscopy (SEM). The system consists of paired ovaries, lateral and common oviducts, a spermatheca, and a genital chamber. Each ovary contains two long, telotrophic-meroistic ovarioles, divided into the terminal filament, germarium, vitellarium, and pedicel. The germarium houses trophocytes and young oocytes, while the vitellarium contains oocytes at various developmental stages. Previtellogenic oocytes feature a cylindrical follicular epithelium without yolk. In contrast, vitellogenic oocytes possess a cuboidal epithelium and yolk-filled ooplasm; during the choriogenic stage, the follicular epithelium becomes squamous, and the ooplasm becomes densely packed with yolk. Histological differences in epithelium and muscle layers distinguish the lateral and common oviducts. Eggs, measuring approximately 0.2 mm by 0.3 mm, are laid on alfalfa stems. Initially whitish, they darken to black during embryonic development. SEM analysis revealed a porous endochorion and an exochorion characterized by transverse and longitudinal lamellar air spaces, likely facilitating gas exchange. These morphological and histological findings offer critical insights into the reproductive biology of H. postica, providing a structural basis for improving pest management and biological control interventions.

Eulasia arctos anatolica, belonging to the Coleoptera order and among the first insects to visit flowers, is associated with plant species such as Onopordum and Euphorbia, playing a significant role in floral ecology and pollination processes. Therefore, in this study, the histological and anatomical structures of the female reproductive system of E. arctos anatolica were examined for the first time using light microscopy and scanning electron microscopy. The female reproductive system of E. arctos anatolica includes a pair of ovaries, each with six telotrophic meroistic ovarioles, a pair of lateral oviducts, a common oviduct, and a genital chamber. SEM revealed that ovarioles are enclosed by a reticulated sheath from the suspensory ligament to the pedicel, with tracheal networks on the sheath surface. Each ovariole contains three to four oocytes; the choriogenic oocyte, located near the pedicel, is larger and anthracite, while the others are whitish. Ovarioles anterior ends are attached to the abdomen wall via the suspensory ligament. Histology of the germarium showed trophocytes, prefollicular cells, young oocytes, and nutritive cord. Early-stage oocytes lacked yolk granules and were surrounded by a single layer of cuboidal to short columnar follicular epithelium. In a late-stage oocyte, the ooplasm was filled with acidophilic yolk granules, and oocytes were encircled by flattened epithelial cells; chorion formation was evident. The pedicel was lined by a single layer of epithelium. This study contributes to the understanding of ovariol development in flower-visiting Coleoptera species and provides fundamental data on the reproductive biology and ecological functions of this group.

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.

Zelus renardii Kolenati, 1856 (Hemiptera: Heteroptera: Reduviidae) is a species of great importance as it is a predator and invasive species. The eggs of this species have previously not been studied in detail. In our study, eggs of Z. renardii were prepared separately for light and scanning electron microscopy examinations and observations were made separately. The cylindrical-shaped eggs were found to be similar to 1.8 mm long and 0.5 mm wide. Eggs had slightly concave and convex sides. A cap region was located at the end of the egg. The operculum was located in the cap region. A micropylar opening was found in the middle of the operculum. The eggs had a white operculum and a brown chorion. The egg operculum surface had irregular pentagonal to hexagonal patterns. The operculum was similar to 0.3 mm wide. Chorion layers were visible in eggshell sections taken from light microscopy preparations and in the samples broken for SEM. One of these layers was the outer columnar exochorion with air chambers between them, and the other was the inner, denser endochorion. This study provides the first detailed description of the egg morphology of Z. renardii, a contribution to the research of the Reduviidae

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.

Agapanthia kirbyi has potential as a biological control agent against certain weed species. In such studies, understanding reproductive anatomy is essential; however, no previous research exists on the reproductive system of A. kirbyi. This study investigated the male reproductive morphology using light and electron microscopy. The male reproductive system comprises a pair of testes, vas deferentia, seminal vesicles, accessory glands, and an aedeagus. Each testis includes two yellowish, oval lobes, each containing 40 follicles where spermatogenesis progresses from the periphery toward the center. The lobes connect via the vas efferentia to the vas deferens and then to the seminal vesicle. Spermatogenesis occurs in three zones: growth, maturation, and differentiation. All stages from spermatogonia to spermatozoa were observed. Spermatozoa are arranged in bundles with spindle-shaped heads and long flagella. The accessory glands, located at the end of the seminal vesicle and opening into the ejaculatory duct, are tubular and wavy, lined by a single layer of granular columnar epithelium. The ejaculatory duct is composed of cuboidal epithelial cells with chromatin-dense, oval nuclei and is surrounded by a muscle layer. These findings provide crucial baseline data for understanding A. kirbyi’s reproductive biology and support future studies in biological control and taxonomy.

ABSTRACT The pine weevil is one of the largest species in the jewel beetle (Buprestidae) family found in Central Europe and Turkey. Chalcophora mariana is generally considered a secondary guest and primarily develops in weakened, decaying, or recently dead pine trees. Its larvae burrow into the wood tissue by tunnelling beneath the bark; in healthy trees, rather than causing sudden death, they lead to wood decay and a decline in lumber quality. To date, no study has examined the gastric caecum, midgut, and Malpighian tubules of C. mariana . Therefore, in this study, the histomorphology structure of C. mariana 's gastric caecum, midgut, and Malpighian tubules was examined in detail using light microscopy and scanning electron microscopy. C. mariana possesses a pair of gastric caecum. Histological sections show that the gastric caecum has a narrow, star‐shaped lumen, and the lumen itself contains long microvilli. In C. mariana , tracheae arranged at regular intervals and round regenerative crypts were observed on the outer surface of the midgut. Histological sections revealed a single‐layered cylindrical epithelium with long microvilli extending from the apical surface. The Malpighian tubules are arranged in three pairs and connect proximally to the hindgut. In histological sections, single‐layered cuboidal epithelial systems and round cells located in the center are conspicuous; microvilli structures are also observed in the visible apical cells. These findings provide important basic morphological data for future comparative and phylogenetic studies on the histomorphology of the gastric caecum, midgut, and Malpighian tubules in the order Coleoptera.

Notonecta maculata is a backswimmer of the family . It is an aquatic predator that feeds on mosquito larvae and other soft-bodied aquatic insects. In this study, the male reproductive system morphology of N. maculata was examined using both light microscopy (LM) and scanning electron microscopy (SEM) for the first time. The male reproductive system of N. maculata consists of a pair of testes, vasa deferentia, seminal vesicles, two pairs of accessory glands, an ejaculatory duct and an aedeagus. Each testis contains six follicles. Histological and SEM analyses revealed bundles of spermatozoa within the follicles. The testis follicles open into the slender and coiled vas deferens. The vas deferens is lined with a simple squamous epithelium, filling its lumen with spermatozoa. It forms a helical structure toward the end and transitions into the seminal vesicle. Just below the seminal vesicle are two types of tubular and coiled accessory glands (Ag1 and Ag2), which open into the ejaculatory duct. Ag1 comprises a simple cuboidal epithelium and contains basophilic secretions and secretory vesicles of varying sizes in the lumen. Ag2 is lined with a simple columnar epithelium; its lumen contains basophilic and eosinophilic secretory material. The ejaculatory duct consists of an intima, a simple cuboidal epithelium and a thick muscular layer. This study contributes to understanding reproductive morphology in aquatic Heteroptera and provides a basis for future comparative and taxonomic studies.

The morphological characteristics of the internal systems in insects are considered important for understanding their biology. This research reports the morphological structures of the salivary glands, digestive tract, and Malpighian tubules of Nepa cinerea, an aquatic predatory insect, using light and scanning electron microscopies. The salivary gland is structurally complex and consists of a paired principal and accessory salivary glands and ducts. The former are small anterior and larger posterior lobes. The accessory salivary gland has both vesicular and tubular structures. The digestive system is divided into three main regions: foregut (pharynx, esophagus), midgut (ventriculus 1, 2, 3), and hindgut (ileum, rectum). The foregut is surrounded by a cuticular intima, a single layer of squamous epithelium with flattened nuclei, and a muscle layer. The midgut consists of a single layer of columnar epithelial cells characterized by chromatin-dense nuclei and a striated border. The epithelium is supported by the basal membrane. The muscles are external to the epithelium. Regenerative cells are located in the base of the epithelial folds. The hindgut is lined with an intima, a single layered epithelium and a muscle layer. Four Malpighian tubules connect at the junction between the midgut and hindgut. These structures are composed of cuboidal epithelial cells characterized by secretion granules, densely packed chromatin in the nuclei, and an apical striated brush border. These findings offer valuable baseline data for future morphological, physiological, and phylogenetic studies on aquatic Hemiptera and contribute to a deeper understanding of insect internal anatomy.

We reported the histological and anatomical analyses of Legnotus limbosus's alimentary and excretory system using stereomicroscope, light and electron microscopy. As a result of the obtained data, the digestive tract of L. limbosus has three main parts: fore, mid, and hindgut. The salivary gland and gastric caeca are structures that assist digestion. The salivary gland is a pair consisting of the principal and accessory salivary glands. The foregut has the pharynx and esophagus. The pharynx structure is located immediately after the mouth and continues with the esophagus as a thin, long canal. The esophagus connects to the ventriculus 1 (V1). The midgut consists of three parts: V1, V2, and V3. The V1 and V2 have a single layer of cylindrical epithelium. However, the proximal and distal parts of V3 have cylindrical epithelium, while the lateral part exhibits a cuboidal form. The ileum and rectum make up the hindgut. The first has a cylindrical epithelium; the second has a squamous epithelium. The two pairs of Malpighian tubules, which are attached to the midgut-hindgut junction, are responsible for excretion and osmoregulation. Crystals with a deltoid shape are seen in the lumen of the Malpighian tubule and the rectum. This study is the first on the digestive and excretory system morphology of the Cydnidae family and will make significant contributions to studies on this subject in the Heteroptera, including this family.

Entomoscelis suturalis is considered a pest. It’s a leaf-eating beetle that can damage crops like rapeseed, mustard, cabbage, and radish. The adults, in particular, are known to feed on these plants, causing significant damage. Understanding the internal anatomy of this pest, particularly the digestive and excretory systems, is essential for identifying potential physiological targets in pest management strategies. This study uses light and scanning electron microscopy to describe the morphology of the digestive and excretory systems of the leaf beetle, E. suturalis. A detailed understanding of these systems is crucial for developing effective pest control strategies. The beetle’s digestive tract comprises a foregut, midgut, and hindgut. The foregut consists of a pharynx, esophagus, crop, and proventriculus, all lined with a muscle layer, a thin epithelium, and an intima. The well-developed midgut is wrinkled due to large, deep folds in its columnar epithelial layer. The hindgut includes an ileum, colon, and rectum; its cell layers consist of an inner cuticular intima, an epithelial layer, and a muscle layer. The excretory system comprises two pairs of Malpighian tubules between the midgut and hindgut. The detailed characterization of the digestive and excretory systems of E. suturalis offers critical insights into the functional anatomy of this destructive pest. These findings not only enrich the anatomical understanding of leaf beetles but also identify structural features that may serve as potential targets for pest control strategies and developing more precise approaches to E. suturalis management and other related crop pests.

We studied the female reproductive system of Oxythyrea funesta, a phytophagous beetle species, utilizing stereo, lightmicroscopy and scanning electron microscopy. The female reproductive system is comprised of two ovaries (each ovary has ten telotrophic meroistic ovarioles), lateral oviducts, a common oviduct, spermatheca, bursa copulatrix and genital chamber. Each ovary was found to have a terminal filament, germarium, vitellarium and pedicel. Trophocytes were found in the germarium anterior region, and prefollicular cells were found in the posterior region. One or two oocytes surrounded by monolayered follicular epithelium were encountered in the vitellarium. As oocyte maturation progressed, nutrient granules in the ooplasma and the vitelline membrane surrounding the ooplasma were distinguishable. The pedicel, which was surrounded by a monolayered cylindrical epithelium with oval nuclei and a thick muscle layer, connected the ovarioles to the common oviduct via the lateral oviduct. Bursa copulatrix and spermatheca structures open into the common oviduct. The bursa copulatrix was surrounded by a monolayered cylindrical epithelium, and its lumen was filled with secretory material. The spermatheca was surrounded by cuticular intima, a monolayered cylindrical glandular epithelium with oval nuclei at the base, and a muscle layer. The findings were compared with the female reproductive system structures of some other species of Scarabaeidae. Some characteristics, including the ovariol number and presence or absence of terminal filament and bursa copulatrix among the species of the Scarabaeidae family, show differences. These features help allow future comparisons with the female reproductive organs of other Scarabaeidae species.

In this study, the egg-laying behavior and morphological structure of the eggs of the aquatic whirligig beetle Aulonogyrus concinnus (Coleoptera: Gyrinidae) were described using stereomicroscopy, light microscopy, and scanning electron microscopy (SEM). In addition, the chorion layering was resolved by staining chorion sections. Samples were collected from Tomarza district of Kayseri province (Türkiye) and left to lay eggs. Although the eggs resemble those of related genera, they are quite different in terms of chorionic structure and reticulation and are separated from other Gyrinidae species. This facilitates linking eggs to adult specimens. Therefore, the clear determination of the egg stage that will create the new organism is important in terms of ecology and taxonomy and will also contribute significantly to biodiversity.

The seven-spotted ladybug, Coccinella septempunctata (Coleoptera: Coccinellidae) L., is a polyphagous predatory species that feeds on many species of aphids and some soft-bodied insects in both larval and adult stages. For this reason, C. septempunctata L. (Coccinellidae) is very important in biological control. In this study, the egg structure and first larval period of C. septempunctata were examined using stereomicroscopy and scanning electron microscopy. C. septempunctata eggs are clear and oval, appearing elliptical dorsally and ventrally and slightly rounded at both ends. The first larvae that emerge from C. septempunctata eggs are dark brown and have 3 pairs of legs. The abdomen consists of 8 segments. In SEM photographs, star-shaped structures were observed on both sides of the strip on the dorsal surface of the thorax and abdomen of the larvae. Large stigma openings were found at equal intervals on the lateral of abdomen. The egg and larval structure of the invasive species C. septempunctata is described in detail.

This study is the first description of the histological and ultrastructure of the internal organs of the superworm Zophobas morio (Fabricius, 1776), which possesses the capacity to be utilized as a nutrient source for sustenance and animal feed. For examination, adult insects’ midgut, Malpighian tubules, testes, and ovarioles were isolated, processed, and analyzed on light microscopy, scanning, and transmission electron microscopy. The results revealed that the midgut displayed numerous gastric caeca and a peritrophic membrane. Cells with well-differentiated cytoplasmic organelles and extended microvilli suggested that the midgut primarily functions in absorption. Malpighian tubules possess a singular layer of cuboidal epithelium characterized by a prominent nucleus. The epithelial cells are filled with secretory granules. Numerous folds of the basement membrane are present in the basal region of the epithelial cells. The female reproductive system comprises a pair of ovaries. Each ovary consists of 6 telotrophic meroistic type ovarioles. The ovariole comprises four delineated areas: terminal filament, germarium, vitellarium, and pedicel. The male reproductive system has a pair of testes. The testis has cysts at different developmental zones (growth, maturation, and differentiation). Spermatogonia, spermatocytes, spermatids, and spermatozoa were distinguished in these zones. Spermatozoa cover more than half of the testis. These features help allow future comparisons with the internal organs of other Coleoptera species with special reference to the Tenebrionidae.

Nepa cinerea is an aquatic predatory insect that plays a key role in the biological control of mosquito populations. This study investigates the morphological structure of the adult female reproductive system using stereomicroscopy, light microscopy and scanning electron microscopy. The reproductive system comprises two ovaries, lateral oviducts, a common oviduct, a spermatheca, and a genital chamber. Each ovary contains five telotrophic meroistic ovarioles, which are divided into four regions: a terminal filament, a germarium with trophocytes and early-stage oocytes, a vitellarium containing previtellogenic, vitellogenic, and choriogenic oocytes, and a long pedicel. Choriogenic oocytes display distinct endochorion and exochorion layers. Each pedicel contains 2-3 pale yellow, oval eggs with brown respiratory horns. Pedicels connect to the common oviduct via the lateral oviducts. The spermatheca, composed of a distal reservoir and a proximal duct, also opens into the common oviduct. The reservoir is cuticle-lined and surrounded by longitudinal muscles and glandular cells. Features such as ovariole number and the presence of respiratory horns differ among aquatic heteropterans. These findings offer valuable insights into the comparative morphology of female reproductive systems in aquatic Heteroptera.