been revealed. Adaptations Eyespots on wings are visual anti-predatory adaptations that have evolved in many species within Lepidoptera. The eyespots are usually dark circles surrounded by a brighter outer layer. The 'pupil' of the eye has a sparkle that mimics the natural reflection of the cornea. These eyes are thought to deflect a predator's attack away from more vital organs and toward that spot on the wings. Bigger eyespots have also been shown to deter predators from attacking completely. Menelaus specifically has an eyespot that is in diameter on its ventral wings that it uses to help avoid predation. Wing Structure The wings of Morpho menelaus are a prime example of iridescent blue coloration in the insect world. The bright and iridescent colors of other butterflies are typically caused by optical interference, but the iridescent blue color of butterflies in the family Morphidae results from the microstructures of the wings. Scientists use SEM, scanning electronic microscope, and spectroscopy, to understand the wings in greater detail. Structural components Each wing is covered in multi-layered scales, which are responsible for the coloration of the wings. The wing colors vary with viewing angle, a phenomenon referred to as structural color. In the female, the dorsal side is more camouflaged while the male presents with a vibrant blue. In the male, the outer layer of the cover scales are long and narrow (), apart, and parallel to the wing plane. The dimensions of the cover scales in other species of the subfamily Morphinae vary greatly, but all are pigment-less and lowly iridescent. The inner layer, called ground scales, are pigmented, iridescent, do not overlap, and are responsible for the blue coloration. They consist of alternating layers of chitin and air, each having its own refractive indexes. The wings of the genus Morpho are noteworthy for their diversity of function, including being hydrophobic, lightweight, sturdy, thermally regulated, and bright blue iridescent. These unique characteristics originate from the photonic nanostructures in the ridges of the scales. There has been increasing interest in the bioengineering community into understanding the structural components of the wing which can have potential applications in creating structural-color devices and selective gas-sensors. Iridescence Iridescence is the phenomenon when light interacts with a particular surface, and at differing angles of illumination and observation the color begins to gradually change. The Morpho Menelaus' characteristic iridescent wings has a unique wing structure. The ground scales are