Microscopic study of male Morpho rhetenor wing scales

Abstract

The morphology of pigmented ventral scales and non-pigmented iridescent dorsal scales of Morpho rhetenor wings were compared using scanning electron microscopy and light microscopy. Sections of wing and individual scales were mounted at various angles on stubs for SEM evaluation. Some scales were embedded in Spurr’s resin and sectioned for LM and SEM.Pigmented scales are ornamented by ridges parallel to the axis of the scale (Fig. 1). They are approximately 1.5 μm apart with holes through the membrane between ridges. The non-pigmented iridescent scales similarly contain a series of parallel ridges, but with several layers of lamellae (Fig. 2). The distance between these ridges is only approximately 0.7 μm (Fig. 3). Much smaller and more frequent holes can be observed between these ridges (compare Figs. 1 and 3). The overlapping layers of lamellae form stacks of thin films, which resemble a “Christmas tree” structure. The space between the overlapping lamellae is 0.05 μm and there appear to be holes through the midrib between lamellar stacks (Fig. 4).