Chrome Domes Making Caterpillars Feel At Home

Insects evolve in ways that protect them against predators and other forms of immediate danger. From the stink bomb of an assassin bug, the stingers of bumble bees to poisonous spiders, many species on this planet have developed in ways to help their species survive and thrive in the wild.

However deep in the rainforests of South America, there comes one elusive bug that is not only totally unique in its survival tactics, but outshines all others, both literally and figuratively. “To avoid being eaten, this creature rides eternal, shiny and chrome,” reports EarthTouch’s columnist Sarah Keartes.


Predation is the relationship between two species, in which one (the predator) hunts, kills and eats the other (the prey.) An interaction between two organisms that benefits one to the detriment of the other is an antagonistic interaction. Predation, herbivory, and parasitism are specific types of antagonistic interactions.

In the case of the Mechantis polymnia [aka the orange-spotted tiger clearwing insect,] one would think it’s shiny, chrome-like shell would leave it prone to predation, by attracting versus repelling predators?

But not the case. In fact, just the opposite is true.

Smoke & Mirrors . . .

Their mirror-like shell surface is actually a tool to help them survive. The polymnia relies on the dynamic of light-bending that actually camouflages this insect, allowing them to blend into his surroundings.

According to Dr. Keith Willmott, one of the world’s leading tropical butterfly experts, “they are actually very hard to see in nature, given the way all the colors are reflected.”

It's also possible that the reflective properties of their chrysalises mask the larvae by making them look like something else entirely: hanging drops of water, shafts of light, empty pupae, or dry, curled leaves.

While to the human eye, their mobile homes appear to be metallic, their shells are actually made up of chitin, the same substance that provides insects like jewel beetles to shine and converts the sea mouse into a rainbow-colored, fiber-optic lamp.

Don’t forget, they turn into butterflies . . .

These caterpillars will eventually transition into butterflies, so their lives as chromed creatures only has to fend off predators for a very short period of time. "The butterflies are only in the pupal stage for around a week, depending on the species," explains Dr Ryan Hill, who reared Mechanitis butterflies for his research in Ecuador. "Afterward, they lose the metallic color."

Costa Rica native Luis Ricardo Murillo-Hiller, who has been studying this species and working with butterfly farmers for 25 years, agrees. "They lose their metallic color almost immediately," he says.

In any event, pretty cool, don't you think? Would make a trip to the Ecudorian rainforest all that more exciting.