The histomorphological structure of the male reproductive system of maize leaf weevil Tanymecus dilaticollis Gyllenhal, 1834 (Coleoptera: Curculionidae)

• Published in: Microscopy research and technique Vol. 82; no. 8; pp. 1345 - 1352
• Main Authors: Ö. Koçakoğlu, Nurcan, Candan, Selami, Güllü, Mustafa
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.08.2019; Wiley Subscription Services, Inc
• Subjects: Accessory gland; Aedeagus; Coleoptera; Corn; Curculionidae; Cysts; Ejaculatory duct; Follicles; Gametocytes; Germ cells; histomorphology; Insects; Light microscopy; male reproduction; Maturation; Microscopy; Peritoneum; Phylogeny; Prostate; Reproductive system; Scanning electron microscopy; Seminal vesicle; Sheaths; Sperm; Spermatids; Spermatocytes; Spermatogenesis; Spermatogonia; Spermatozoa; Stereomicroscopy; Tanymecus; Tanymecus dilaticollis; Testes; Vas deferens; male reproduction; Tanymecus dilaticollis; Curculionidae; histomorphology
• ISSN: 1059-910X; 1097-0029
• DOI: 10.1002/jemt.23286

The histomorphology of the reproductive system and the germ cells has been useful to establish phylogenetic relationships in many insects. However, these elements remain little known in the Curculionidae. In this study, histomorphological structure of the male reproductive system of Tanymecus dilaticollis, which is economically important, is described, illustrated using stereomicroscopy, light microscopy, and scanning electron microscopy techniques, and discussed in relation to other Coleoptera species. Results showed that distinctive features of the male reproductive system of T. dilaticollis consist of a pair of yellowish testes, a pair of seminal vesicles, a pair of vasa deferentia, an ejaculatory duct, accessory glands, prostate glands, and aedeagus. Each testis is subdivided into two testicular follicles, enclosed by a peritoneal sheath. Each follicle of the mature testes is full sperm cysts with germ cells at various stages development of spermatogenesis. The testes have four types of germ cells (spermatogonia, spermatocytes, spermatids, and spermatozoa). They are occupied by the growth zone containing spermatogonia and spermatocytes, the maturation zone containing spermatids, while differentiation zone containing spermatozoa. There is a seminal vesicle at the center of each testis. Most mature sperms are stored in the seminal vesicle. Each testis is attached to the vas deferens by a stalk‐like seminal vesicle. In the distal part, vasa deferentia fuse with the ejaculatory duct. It is linked to the aedeagus. The provided results will contribute to the understanding of the reproductive cell biology of Curculionidae. Tanymecus dilaticollis causes great damage in the leaf parts of the maize plant. The male reproductive system in T. dilaticollis consists of a pair of testes each with a seminal vesicle, two vasa deferentia, a pair of accessory glands, a pair of prostate glands, a median ejaculatory duct, and aedeagus.