Glasswing Butterflies Want To Make Something Perfectly Clear | Deep Look

Ever wanted to be invisible? The elusive glasswing butterfly knows just how to do it. Its transparent wings, covered in an anti-glare nano-coating, help it hide from its predators in the rain forest.

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Ever wished you could be invisible? Fade into the background. Unnoticed. Unseen. For glasswing butterflies, the rainforests
of South and Central America are full of hungry predators they’d like to hide from. Some butterflies use cryptic camouflage to
hide themselves by blending in with their surroundings. Others use aposematism -- vivid colors and
patterns that warn predators they’re toxic. Glasswings do have some warning markings -- see
that bright slash of white on black? But that’s not their main defense. Their transparent wings enable them to disappear
into the background wherever they go. Even while flying. This little caterpillar is a baby glasswing
and it's already good at staying out of sight. You can see through parts of its exoskeleton
… offering a window into its most recent leafy meal. That exoskeleton is made of a material called
chitin that’s both strong and flexible. In most insects, chitin is mixed up with pigments
that give it color. But some parts of the glasswing lack pigment
entirely. Once it’s had its fill, the caterpillar
suspends itself under a leaf or stem. It becomes a chrysalis. Inside, it’s undergoing a metamorphosis. About a week later, the transformation is
complete. An adult butterfly emerges. It unfurls its delicate, new wings, revealing
its window panes for the first time. At the Nipam Patel Lab at UC Berkeley, researcher
Aaron Pomerantz is studying how exactly the glasswing butterfly forms those transparent
wings. They’re made of that same clear chitin from
when it was a caterpillar. But in these wings, the chitin’s all stretched
out -- incredibly thin and stiff. And that layer of chitin is exposed. Other butterfly wings are covered in colorful
overlapping scales that protect their wings from the elements. The glasswing does have colored scales…
on its body and the fragile edges of its wings. But the scales on these window panes don’t
look like scales at all, more like tiny hairs. They’re skinny and spread out -- they
let the light pass by. But having clear wings doesn’t help you
hide if they’re shiny. Zoom way in past the hairs, and you’ll see
the surface looks rough. It’s covered in miniature towers made of
wax. They’re called nanopillars. If the surface of the wing was smooth, light
would bounce off of it. The nanopillars are nature’s original anti-glare
coating. Researchers found that when they used chemicals
to remove the nanopillars, the wings glimmered more. While some other butterflies gleam in the
sunlight, the glasswing reflects almost no light at all. Glasswings excel at being dull. And that helps them hide in plain sight What makes glasswings special isn’t their
luster, but their ability to fade away. Heya Deep Peeps, it's Laura. We've got more butterfly-themed Deep Look
episodes for ya. Like why behind every beautiful butterfly
there’s a voracious caterpillar. And how blue morpho butterflies have some
of the most brilliant blues in nature, without any blue pigment at all. Instead they harness the physics of light at the nanoscale. See ya next time.