Marvels of Nature-Beautiful and Colorful Display of Butterflies

A butterfly has four wings.  Two are fore wings and two are hind wings. They are attached to the second and the third thoracic segments. Strong muscles in the thorax move the wings upside down in the figure eight pattern during their flight.

Butterfly wings are made up of two protein membranes that are covered in thousands of scales and tiny hair. These wing scales are overlapping pieces of the protein chitin and are modified plate like setae. The colors and patterns of the butterfly come from these layers of tiny scales. 

The wings are made of two chitinous layers that are nourished and supported by tubular veins. The veins exchange oxygen. The wings are covered with thousands of colorful scales together with many hairs.

The scales are the overgrowth of the body wall and have modified plate like setae. The front and the back wings have different patterns. The male butterflies have scent scales which are modified wing scales situated on the forewings to release pheromones. These are chemicals to attract females of the same species.

Butterflies have beautifully colored wings. They have ultraviolet patterns in the wings. But these ultraviolet patterns are invisible to us, but visible to other butterflies. The colorful wings of the butterfly serve various purposes. They are:

Camouflage, in which the color of the animal helps it blend into the environment, hiding the insect.

Attracting and finding mates, who look for certain colors and patterns.

Warning coloration: Brightly colored butterflies mimic a similar brightly looking butterfly.

Deceiving predators: Some butterflies have eyespots on their wings. These eyespots will appear as animal faces for their predators.

Butterflies are cold blooded animals. When they get too cold, they can spread these wings in the sun and pump blood into the wings and this will increase their body temperature.

Butterflies possess striking color display as they fly from flower to flower gathering nectar. Their brightly colored wings reflect and change colors before our eyes. This vivid color display dazzles our eyes. How do the butterflies get their colorful displays? They get their striking color displays from two sources. They are:

1.    Ordinary or pigmented colors

2.    Structural colors.

The ordinary or pigmented colors come from normal chemical pigments. The normal pigments absorb light of certain wavelengths and reflect others. Most of the butterflies get their different shades of brown and yellow from melanin, the color pigment.

Structural color is the color that stems up from the specific structure of the butterfly wings. It also explains why some of the butterfly colors appear so intense. This quality of changing colors is known as iridescence. It occurs when light passes through transparent multi-layered surface and undergoes multiple reflection. The multiple reflections compound one another and intensify colors.

Iridescence or goniochromism is the phenomenon of certain surfaces that appear to change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, butterfly wings and sea shells, as well as certain minerals. Iridescence also means a lustrous rainbow-like play of colors caused by differential refraction of light waves that tend to change as the angle of view changes.

Butterfly wings are covered by thousands of microscopic scales split into two or three layers. Each scale has multiple layers separated by air. The equally spaced layers of butterfly wings create multiple instances of constructive interference.

When light strikes the different layers of butterfly wings it is reflected numerous times and the combination of all these reflections causes very intense colors. Most of the butterflies display ultraviolet spectrum visible only to other butterflies and not to human beings.

The combination of a butterfly’s structural and pigmented colors can create interesting effects. For example a butterfly with a yellow pigment creates blue iridescent color, we will see green shade made by merging of the two colors. We will see yellow, or blue or green or a combination of all the three as light enters at different angles and as the butterfly moves its wings.

Butterflies with bright colors and patterns are advertisements to their predators that they are distasteful. There are also butterflies that are brightly colored mimicking other species to fool their predators.

The  scales form patterns and provide the butterflies with camouflage and help them to hide from their predators by easily blending with the environment. The common camouflage of butterflies are the wing patterns that resemble the leaves of the tree or the barks of a tree.

The scales on the top of the butterfly wings are brightly colored while the scales on the underside are patterned for camouflage while the butterfly rests.

Butterflies use colors and patterns for attraction and deception. Some butterflies look for certain colors or patterns while searching their mates. The ultraviolet patterns on the wings of the butterflies are invisible to us but are used by other butterflies to identify their mates.

Knowledge of science and its application has given us a breakthrough to understand the physics behind the colorful display of butterflies. While we understand the structural adaptation and the behavior of this small insect, we should not forget to wonder the marvels of Nature.