Histomorphological Structure of Male Reproductive System in Capnodis tenebrionis (Linnaeus, 1761) (Coleoptera: Buprestidae)

Abstract

In this study, anatomy and histology of the male reproductive system in adults of Capnodis tenebrionis, which are called the Mediterranean flat-headed root-borer, are described and illustrated by using light and scanning electron microscopies. Data from the male gonad of this species provide more extended and precise knowledge regarding to histoanatomical structure of the testis in Buprestidae. In this study, male reproductive system of C. tenebrionis consisted of two testes, two vas deferens and two accessory glands which are long tube-like, a pair of spermatophoral glands, an ejaculatory duct, and an aedeagus. Each testis was subdivided into a lot of tubular testicular follicles. Vas deferens was a tubular structure and located just below the testis. Its wall was surrounded by a monolayer cylindrical epithelium and a thin muscle layer. In its lumen, it was observed that mature sperm stacks were stored. Vas deferentia were immediately opened ejaculatory duct. It was surrounded by a single layered epithelium and a very thick muscle layer. Long, tubular, convoluted a pair of accessory glands were seen which were connected to the ejaculatory duct. In the accessory glands, it was seen that the wall was surrounded by monolayer cubic epithelium and sheath. In addition, it was seen that oval, sheet-shaped, paired spermatophoral glands were opened into the ejaculator canal. Its histological examinations revealed that the wall was surrounded by multilayered epithelial cells and muscle layer. The ejaculatory canal was connected to the aedeagus with very dense striated muscle bundles. The aim of the present study is to contribute information on the histomorphology of the male reproductive system of the insects.

Structural and histological observations on the male reproductive system of adult red poplar leaf beetle Chrysomela populi Linnaeus, 1758 (Coleoptera: Chrysomelidae)

“…Barker (1989), Goldson and Emberson (1981) and Özyurt Koçakoğlu et al (2019) state that in Hyperodes bonariensis Kuschel (Curculionidae) and T. dilaticollis (Curculionidae), there is a pair of blind‐ended tubules accessory glands and paired multilobed prostate glands. C. tenebrionis (Buprestidae) has two tubular accessory glands and two sac shaped spermatophoral glands (Çağlar et al, 2020).…”

“…The upper part containing the spermatogonia is a growth zone (I) where the spermatogonia undergoes a multiplication stage and is usually encapsulated; maturation zone (II) is where the maturation divisions take place; and finally comes the transformation zone (III) where the spermatocytes transform into spermatids and finally into mature spermatozoa. The entire process, or spermatogenesis and spermiogenesis, thus regularly takes place in the testicular follicle (Alzahrani et al, 2013; Barker, 1989; Çağlar et al, 2020; Candan, Özyurt Koçakoğlu, & Suludere, 2018; Cerezke, 1964; İzzetoglu & Gülmez, 2018; Özyurt, Candan, & Suludere, 2015; Özyurt Koçakoğlu et al, 2019; Özyurt Koçakoğlu et al, 2020; Phillips, 1970; Snodgrass, 1935; Suzuki, 1988; Wu et al, 2017).…”

“…In C. populi , the surface of the testis is covered with a peritoneal sheath which is light orange in color (Çağlar et al, 2020; Özyurt Koçakoğlu et al, 2020). But, in C. herbacea (Chrysomelidae) and C. tenebrionis (Buprestidae), the testes are yellow.…”

“…Each testis in Phyllocaris cyanicornis (Chrysomelidae) and C. herbacea (Chrysomelidae) has 40 follicles (Kasap & Crowson, 1979; Özyurt Koçakoğlu et al, 2020). In C. tenebrionis (Buprestidae), each testis consists of many follicular tubules (Çağlar et al, 2020; Gardner, 1986). Alzahrani, Abdelsalam, Elmenshawy, and Abdel‐Moneim (2013) reported that each testis of R. ferrugineus (Dryophthoridae) has about 50–60 follicles.…”

“…The internal genital organs serve to house the germ cells, provide their nourishment and provide a protected area within the body where they can undergo some or all of the development that brings them to a stage ready for conjugation; these include devices for securing fertilization and glands for the production of a mucous or adhesive or protective medium; and finally, they expel germ cells from the body at the appropriate time (Snodgrass, 1935). In an adult insect including Chrysomelidae, the basic parts of the male reproductive system include a pair of testis, a pair of lateral canals, a pair of vas deferentia, and an ejaculatory duct (Çağlar, Özyurt Koçakoğlu, & Candan, 2020; Hopkins, Steelman, & Carlton, 1993; Kasap & Crowson, 1979; Özyurt Koçakoğlu, Candan, & Güllü, 2020; Snodgrass, 1935; Suzuki, 1988). Each testis typically consists of a group of sperm tubes or testicular follicles which contain male reproductive cells in successive stages of development and other cells associated with germ cells in varying capacities (Kasap & Crowson, 1979; Snodgrass, 1935).…”