Functions and Morphological Structure of Respiratory Horns and Eggs of the Biocontrol Agent <i>Nepa cinerea</i> Linnaeus, 1758 (Hemiptera: Nepidae)

In this study, the oviposition behavior of the predatory water scorpion beetle Nepa cinerea Linnaeus, 1758 (Hemiptera: Nepidae), morphological structure of eggs, and respiratory horns are described using stereo, light, and electron microscopes. The first recorded N. cinerea specimens from Kırıkkale province were examined. N. cinerea females lay their eggs by sticking them vertically to the substrate. Eggs are elliptical, approximately 1.3 mm wide and 1.63 mm long. Fresh eggs are yellow, darkening. There are 5-8 respiratory horns at the anterior pole of the egg shell. There are numerous air pore openings on the respiratory horn surface. There are hexagonal patterns on the chorion surface. The egg is surrounded by the endochorion with vitelline envelope, the exochorion with tubercle, and the intrachorionic air space between them. The nymph hatches from the egg in 8-10 days. In this study, the development of N. cinerea, which plays an important role in the aquatic ecosystem, the structure and number of respiratory horns in its eggs, and the histology and anatomy of the chorion were emphasized. Clearly determining the preadult egg period that will ensure the continuity of the species will make a significant contribution to biodiversity and biocontrol studies.