Crystalline wax coverage of the imaginal cuticule in Calopteryx splendens (Odonata: Calopterygidae)

Abstract

In this study we use high resolution SEM to describe the diversity of wax crystals and their distribution on different morphological structures in male individuals of Calopteryx splendens. The entire cuticle surface of this damselfly, with the exception of ommatidia and ocelli, is covered with crystalline wax in dimensions from submicron to micron range. It is shown that shape – rod-like, plate like, filamentous, etc. –, size, and density of crystals vary on different surfaces and in individuals of different ages. Additionally, we demonstrate different types of damage to the crystalline wax layer: scratches, compressions, wear, and contamination. The primary function of the wax crystalline coverage in odonates is, presumably, reduction of surface wettability by water (superhydrophobicity). However, other functions are also discussed, especially in such specialized body areas as postero-ventral parts of male abdomen, the so called ‘lantern’.