Ultrastructural Changes in the Ovariole of Isophya nervosa Ramme, 1931 (Orthoptera: Tettigoniidae) and Egg Morphology

Microsc Microanal. 2022 Mar 14:1-7. doi: 10.1017/S1431927622000319. Online ahead of print.

Abstract

This study was conducted to assess the morphology of eggs and histology of the ovaries in female Isophya nervosa Ramme, 1931 (Orthoptera: Tettigoniidae). While the egg morphology of I. nervosa was studied and examined by a stereomicroscope, a light microscope, and a scanning electron microscope, respectively, the morphology and histology of the ovary of this species were studied and examined by a stereomicroscope, a light microscope, a scanning electron microscope, and a transmission electron microscope, respectively. We found that the adult female had two pairs of ovaries, lateral oviduct, common oviduct, and spermatheca. Morphological study of the ovariole revealed that it is categorized under panoistic type of ovariole which is divided into three regions, the terminal filament, the germarium, and the vitellarium. We also observed that the eggs in I. nervosa have an ellipsoidal shape and are brown in color. Three different layers such as extrachorion, exochorion, and endochorion were observed. When the egg morphology is examined, it is understood that the surface pattern of the egg and the features of the micropylar areas may be distinguishing characters at the subfamily level, in addition to known classical taxonomic characters.

Keywords: female reproductive system; insect histology; scanning electron microscopy; staining; transmission electron microscopy.