Wings like windows
Most of each wing has no coloured scales, so you can see straight through it.
The cloud forest · Butterflies and moths
Glasswing butterfly
Greta oto
A small butterfly whose wings are as clear as glass, framed in brown with a white bar near the tip.
- Size
- Wingspan 5.5 to 6cm
- Look for it
- All year round
- Where
- Forest from Mexico to Colombia, and its relatives across the Andes
Flits after you, half invisible. Move your pointer and see.
When to look
Glasswing
Good to know
Six things about the glasswing
No reflections
The clear parts are covered in tiny bumps that stop light bouncing off, so the wings do not even glint.
Hard to follow
A bird sees only the thin brown outline, and loses it against the leaves.
Stronger than it looks
It can carry about forty times its own weight.
Poisonous as well
Its caterpillars eat poisonous plants and the adults keep the poison.
Little mirrors
In Spanish it is called espejitos, which means little mirrors.
The real thing
Photos of the glasswing
Photos are from Wikimedia Commons, used under the free licences shown. They have been resized, and cropped where they appear in link previews.
How to spot one
Look low down in the shade along a damp forest trail. You will notice the white bars moving before you see the butterfly.
How to help
It needs shady forest with the nightshade plants its caterpillars eat.
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