You can see the background through much of a glasswing butterfly's wings. The clear areas are not empty spaces: they are living-made structures with an intricate surface.
Greta oto is one of several butterflies with transparent wings. Dark borders frame its clear sections, making the effect especially striking.
Less coverage, more light
Most familiar butterfly wings are covered with overlapping scales. In clear parts of Greta oto wings, the scales are fewer and shaped differently.
A 2021 study in the Journal of Experimental Biology examined how these regions develop. Sparse, narrow scales expose more of the wing membrane.
That is only part of the explanation. A transparent sheet can still reflect light strongly enough to reveal itself.
A surface that reduces glare
The researchers also found tiny structures on the membrane, including a wax-based layer of unevenly arranged pillars.
These features help reduce reflection. More light passes through rather than bouncing back toward an observer.
Earlier research in Nature Communications examined the wing's antireflective properties across different viewing angles.
The result is a butterfly wing that performs a delicate balance: it remains a working flight surface while offering less obvious visual coverage.
Clear does not mean invisible
The body, veins, and wing borders are still visible. Lighting and background also affect how easily an observer notices the insect.
A glasswing on a leaf may be easy to see once you know where to look. The surprise is how much detail disappears into the scene beyond it.
Wonder at two scales
A photograph introduces the glasswing's beauty. A microscope reveals another world of shapes too small for our eyes.
The next time transparent wings catch your attention, imagine the structures beneath that simple-looking view. Nature's clearest surfaces can contain some of its most intricate detail.
Photo credits
Featured image: Greta oto, Houston Museum of Natural Science.jpg — FreeMediaKid!; CC BY 4.0.
Body image 1: Glasswinged butterfly (Greta oto).jpg — liz west from Boxborough, MA; CC BY 2.0.
Body image 2: Greta oto qtl2.jpg — Quartl; CC BY-SA 3.0.
Photographs resized for web display where available.