Color Me Intrigued: the relationship between insects and color

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    Whether in the wild, in display cases, or just in photographs, I’ve probably looked at more insects over the last four days than I have over the last couple of months combined. I noticed that one of the most striking ways insects are diverse is in the wide array of colors and patterns they come in. I decided to investigate the relationships between insects and color- why and how they look the way they do, as well how they themselves experience color.


As might be expected from their diversity in other areas, not all insects have the same color vision. Unlike most humans, who have three types of cones in our eyes, most insects have only two. This makes it difficult for them to tell the difference between certain colors, just like humans who are colorblind. However, pollinating insects like bees and butterflies do have three types of cones and thus have true color vision. One facet of color vision that is true for all insects is that the spectrum of wavelengths they can detect is shifted down compared to ours: they are able to see ultraviolet but not red.




A naturally following question is how the color of the insect itself originates. There are two main ways that color is produced in insects: pigmentary and structural. 

Pigments are chemical compounds of specific colors. A familiar example is melanin, which, in insects just as in humans, produces colors ranging from black to brown to yellow. Another common group of pigments are carotenoids. Carotenoids are yellow, orange, and red colors which can only be synthesized by plants, which insects acquire through their diet. 

Structural colors are produced by physical, not chemical, structures which are small enough to interact with light waves. They often produce an iridescent appearance, and can be used in combination with pigments to make a variety of colors. There are many types of these structures. Some Lepidopterans have modifications to the scales on their wings which reflect only the desired blue or green. Some beetles and flies have tiny fibers of chitin layered in a helical pattern which produces iridescence or even polarizes light. And many dragonflies are blue by the exact same mechanism as the sky- microscopic particles scattering light.


So, what is the point of such a wide array of colors? Like all other adaptations, the purpose of these colors is always to aid in survival, although this takes two completely opposite forms: trying to avoid being noticed and deliberately trying to be noticed. 

The concept of camouflage is doubtless a familiar one. Organisms which match the color of their environment are less likely to be noticed and subsequently eaten. Many insects mimic specific objects such as leaves or sticks in order to appear of low interest to predators. One specific type of camouflage is countershading, in which an organism is darker on the dorsal side and lighter on the ventral side in order to blend into either sunlight or shadow. 

The opposite strategy to camouflage is called aposematism. Aposematic coloration often utilizes bright, contrasting colors in order to advertise that the insect is unpalatable or otherwise painful to attempt eating. Predators which have attempted to eat one of these unpalatable insects will learn to avoid insects with that appearance in the future. Unrelated species may take advantage of this: Batesian mimicry is when a palatable species mimics the coloration of an unpalatable one. Two examples of mimicry and aposematism are the viceroy butterfly mimicking the poisonous monarch butterfly and hover flies mimicking bees.


As we continue to admire the beauty of insects over the next two weeks, let’s remember to appreciate the gift of our color vision and remain curious about the mechanisms and purposes of the colors we see in the natural world!





Works Cited


Daly and Doyen’s Introduction to Insect Biology and Diversity (Third Edition) by James B. Whitfield and Alexander H. Purcell III, pp. 58-60, 204-210


Color Vision, ENT 425, North Carolina State University, https://genent.cals.ncsu.edu/color-vision/

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