from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A cell in the outer wing of insects which is often thickened or coloured and so stands out from other cells.
from the GNU version of the Collaborative International Dictionary of English
- n. A thickened opaque spot on the wings of certain insects.
from The Century Dictionary and Cyclopedia
- n. The carpus or stigma, a peculiar mark or spot on the wings of some insects.
Carpus: the pterostigma of Odonata: the extremity of the radius and cubitus of the primaries: that point in the wings at which they are tratsversely folded.
Parastigma: = pterostigma; q.v. Parastigmatic glands: small, circular glands, which secrete a waxy powder, sometimes present around the spiracles of Coccidae.
Apical cells or cellules: Trichoptera; the series of cells along the outer margin of wing from pterostigma to arculus.
Without the pterostigma, self-exciting vibrations would set in on the wing after a certain critical speed, making gliding impossible. "