Butterflies are adaptive creatures that adjust to their surroundings according to the traits they possess and develop over time. They have different color patterns and glow brilliantly in different light conditions, but people wonder if they can produce light in the dark because they are not commonly seen at night.
Can Butterflies Glow in The Dark? Butterflies do not glow in the dark because they do not have bioluminescence chemicals that emit light. They have particular structural colors and wing patterns to reflect specific wavelengths of light, as they appear shimmery only when light reflects from the UV patterns on their bodies. Moreover, African butterflies glowed with green eyes when the bioluminescence gene from jellyfish was inserted into their bodies. Some caterpillars from the Lepidoptera family also glow at night.
They are famous for their various color combinations, pollination, flight patterns, and camouflaging techniques in different life stages. The caterpillar of each species has a different color, and it changes its appearance when it emerges from the chrysalis after completing the metamorphosis stages.
Why butterflies cannot glow in the dark?
Butterflies have ultraviolet light patterns on their wings. They can emit or reflect light from their bodies in various light conditions.
No bioluminescence chemicals
They do not have bioluminescence chemicals in their bodies and wings, which affects their appearance in the dark.
Once, my friend told me that fireflies, click beetles, and other insect species can emit light in the dark because they have bioluminescence chemicals in their bodies, which cause a specific chemical reaction to occur and give them a shiny appearance in the darkness.
I asked him about the butterflies appearing at night because I never see them shining in my garden when I come home late.
He said butterflies have different biology than glowing insects and do not have any chemical reaction in the dark to glow due to the lack of bioluminescence chemicals.
Structural colors and wing patterns
Butterflies have striking and beautiful color patterns on their wings, and the shades are due to their two types of colors.
For example, the ordinary and the structural colors cause a colorful appearance. The pigmented or ordinary colors are because of the chemical pigments in their wings that absorb and reflect specific light wavelengths.
However, the structural colors cause the shades to change in different lights and make the patterns look more or less intense.
They reflect light and show different shades in intense and ambient light but do not glow in darkness when no light falls on their wings.
They can show different colors on their wings in the daytime but cannot produce luminescence or emit light from body parts in darkness, like fireflies or click beetles.
Reflective Scales
Butterflies have different wing sizes and are covered with thousands of scales that reflect carrying wavelengths.
My neighbor is a professor at the University and teaches entomology to students. He has many years of experience in this department and has performed experiments in the laboratory about the genetic features involved in the colorful appearance of butterflies.
Once, he told me many interesting facts about how butterflies glow or appear so colorful in the daytime and less bright in the low night conditions.
He said the light falling on the scales reflects at different angles, and they glow, but they do not produce luminescence when there is no light.
They show different shades due to the reflectance and absorption of varying wavelengths and also reflect UV light. However, the reflective scales do not produce their light at night when there is no light around them.
Shimmery appearance in different conditions
Some of their species have shimmery scales due to the specific scale arrangements, and they show iridescence when light falls on them.
They do not shine in the dark because the shades or shimmer appear only in the presence of light, no matter how intense or low.
Moreover, I read a book about insects and their appearance in different light conditions and learned that butterflies show particular hues and shades in bright light and appear dull in low light.
However, they cannot produce or emit light to glow in total darkness. For example, I caught a butterfly from my yard with a bright and shimmery appearance on its wings.
I experimented to see if it glows in the dark room when no light falls on the wings because it showed the contrasting colors in sunlight.
I took it to the basement room and closed the curtain and lights to create darkness. I was surprised to see that it does not produce luminescence.
How do African butterflies glow in the dark?
They do not naturally glow in the dark. However, some American scientists performed experiments in laboratories with African butterflies to see if they could produce luminescence in the dark when particular changes in DNA or genes are done.
They experimentally inserted the jellyfish marker gene in butterflies under controlled conditions. Only a few eggs (5%) out of 10,000 can survive and hatch into adults.
The inserted jellyfish gene has a bioluminescence chemical that reacts with the genes and produces the specific chemicals through a reaction.
They noticed that only 15% of the hatched species could develop the bioluminescence gene and process the chemicals to produce the green glow in their eyes in the pitch dark.
Scientists performed this experiment to understand the changing colors and wing patterns in butterflies and paved the path for much research in the future.
What factors affect the glowing appearance of butterflies?
Various factors influence the colorful appearance and glow of butterflies in different light conditions. Some significant factors include light intensity, angle, environmental conditions, scale arrangement, age, species, and genetic mutations.
For example, my brother studied the behavior and color variations in each species because he has many butterflies in our farmhouse.
He told me that the angle at which light falls on their wings and scales reflects the rays in different directions. He further said the light angle also decides the intensity of the specific color appearing to the viewers.
I was surprised to hear that their age also affects the glow and colors of their wings because they lose their scales with age as they fly under different environmental conditions.
The arrangements of scales and color pigments in each species also affect their wings’ appearance and color.
Moreover, he explained that they identify the species from their bright appearance and patterns and attract mates by flapping and showing shimmery colors.
Do caterpillars glow in the dark?
Some caterpillars can glow at night when blue UV light falls on them and appear green. UV light is also called blacklight and emits ultraviolet rays.
I studied that Luna moth caterpillars, Slug moth caterpillars, Giant leopard moth caterpillars, Sphinx moth caterpillars, and Polyphemus moth caterpillars can glow at night when UV light falls.
You can spot the caterpillars at night using a flashlight and UV light. Use a flashlight to find the way to caterpillar host plants, and turn on the UV flashlight to find the caterpillar in the vegetation.
You will notice white or green glowing caterpillars on the plant stems, and leaves appear purple in UV light. Other insects, like spiders and moths, emit light in the UV light along with the caterpillars.
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