Piyakorn Boonyoung, Sinlapachai Senarat, Jes Kettratad, Wannee Jiraungkoorskul, Narit Thaochan, Kong-Wah Sing, Theerakamol Pengsakul, and Pisit Poolprasert

DOI: 10.14456/sjst-psu.2020.112

pp. 873 - 878

Abstract

The gonadal structure of insects has been well reported but there is a lack of such information from tortoise beetles that
are an economically important insect. In this study, the gonadal structure and differentiating stage of gametogenesis of tortoise
beetles Aspidomorpha sanctaecrucis are examined using the histological technique. At the level of light microscopy, our results
revealed that the A. sanctaecrucis male reproductive system has a pair of testicular structures that consist of six seminiferous
tubules. All zones contained various stages of spermatogenesis and could be divided into five stages depending on the shape and
histological organization, particularly chromatin organization, which was divided into spermatogonia, primary spermatocytes
with 8 sub-steps (leptotene, zygotene, pachytene, diplotene, diakinesis, metaphase, anaphase, and telophase), secondary
spermatocytes, spermatids (two sub-steps), and spermatozoa. A pair of ovaries was observed in the female A. sanctaecrucis. Each
ovary is considered to be a meroistic ovariole that exists with nurse cells. The differentiating oogenic stages including
previtellogenic and vitellogenic stages were observed. Our study provides baseline data that will be useful for future work
involved in the ultrastructure and physiology of the reproductive tissue in tortoise beetles, especially the differential
characterizations of the seminiferous tubule and ovarian type in beetles.