OK, when I was a kid, I was told that even lightly touching a butterfly’s wings would destroy its ability to fly. It had something to do with the powder on its wings. Anyway, I don’t really want to test this, so, is this true or BS?
It’s kinda true and kinda BS.
The “powder” isn’t really powder. This actually refers to the tiny scales on the butterfly’s wings. The wings are very delicate, and you can easily scrape off the scales and damage the wing.
It is possible to touch the wings lightly enough that you don’t cause damage. However, the amount of force necessary to damage the wings is still really far into the “lightly” range according to human sense of touch.
Researchers actually grab and sometimes tag butterfly wings, so the idea that it’s not possible to touch them in such a way that they can’t fly afterwards is clearly false. However, the wings are so delicate and easy to damage that for all practical purposes, it’s much better to tell kids not to touch them at all.
Yes, it’s better not to touch butterfly and moths wings, but the loss of the scales alone doesn’t have much effect on whether they can fly or not. One regularly sees older butterflies which have clear patches in the wings where all the scales have rubbed off. Also, butterflies can fly even with big chunks lost from their wings. Sometimes you can see symmetrical bite marks on the wings indicated a bird tried and failed to catch one when it had its wings folded.
To some extent, the scales are actually designed to be lost. Scales help butterflies and moths avoid capture in spider webs, since when the scales get stuck to the sticky silk they detach allowing the insect to fly away.
Back in the '80s, we (the science department of a S. GA high school) worked on a project where we tried to help track the migratory routes of the cloudless sulfur and the Gulf fritillary butterflies. We had a big soccer goal-looking trap to catch them with. We took them, marked their wings with a rubber ink stamp, recorded the info, and let them go, hoping they’d be caught again in a trap further southwest of us. Can’t say I ever heard of any results from that study, but the critters always flew away just fine.
Here in Panama they are sometimes marked just using a pen.
Here’s another butterfly-marking study in Hungary.
I want to see a butterfly marked with a human tattooed on its ankle.
I want to see a butterfly tattooed with a thunderstorm. Or a fractal pattern.
No, on its lower thorax.