Moths do something similar using chitin instead of glass.
At the base of the leading edge of the hind wing they have a relatively long spine, the frenulum, that hooks under a clasp, retinaculum, on the fore wing.
The reason is to 'lock' the fore- and hind wing together during flight.
Image shows the frenulum of a male noctuid moth, Cynical Quaker.
2nd image shows the tip adjacent to a micrometer scale
(wing mounted on a slide beneath a cover slip; not a recommended setup for a 40x M Plan objective).
NU.
student of entomology
Quote – Holmes on ‘Entomology’
” I suppose you are an entomologist ? “
” Not quite so ambitious as that, sir. I should like to put my eyes on the individual entitled to that name.
No man can be truly called an entomologist,
sir; the subject is too vast for any single human intelligence to grasp.”
Oliver Wendell Holmes, Sr
The Poet at the Breakfast Table.
Nikon camera, lenses and objectives
Olympus microscope and objectives
