The oviposition mechanism in Habrophlebia eldae (Ephemeroptera: Leptophlebiidae)

Abstract

Females of Habrophlebia eldae release eggs into the water by penetrating the surface with the ovipositor. Ultrastructural investigations (SEM, TEM) confirm that at rest the ovipositor of H. eldae is composed of a proximal sclerous region and a distal membranous region. During oviposition, the membranous region unfolds a telescopic tube made up of a thin cuticle. At rest, this telescopic structure is kept folded inside the ovipositor. The extension of the structure seems to be passive, caused by the passage of the eggs, pushed out by the peristaltic movements of the net of muscle fibres surrounding the oviducts. The contact of the membranous distal region of the ovipositor with water triggers egg laying through extension of the telescopic tube. Numerous mechanoreceptors, in the form of short bristles, are located ventrally in the membranous region of the ovipositor and seem to be involved in water perception.

Keywords:

• ultrastructure
• mechanoreceptors
• ovipositor
• aquatic insects
• mayfly

Acknowledgements

This research was partially supported by FISR MICENA funds.