pterostigma

A pterostigma is also found among other insects, such as bees.

In most families there is a structure on the leading edge near the tip of the wing called the pterostigma.

The pterostigma is pale brown and outlined in black.

The wings are hyaline with a dark well marked pterostigma.

It has large brown/black rectangular pterostigma and blue eyes.

The wings are hyaline, with yellow or pale brown pterostigma.

The forewings are incomplete, with the tip beyond the end of the pterostigma not present.

The black pterostigma is carried near the wing tip.

The pterostigma is orange and the thorax usually bears pale stripes.

The pterostigma or the wing spot is diamond-shaped and is dark brown in colour.

The pterostigma in their fore-wing has the characteristic of not being closed proximally.

Other than the basal cross vein the pterostigma is not crossed by any veins.

The functions of the pterostigma are not fully known, but it most probably has an aerodynamic effect and may also have a visual function.

Pterostigma - is present for some species.

The pterostigma of immature males are almost white.

Tests show that with the pterostigma, the critical gliding speed is increased 10-25% on one species of dragonfly.

Styporaphidia possesses the primitive feature of two crossveins in the pterostigma.

In both sexes, there is no pterostigma.

The pterostigma is also colored brown.

The pterostigma are pale with a border of black veins and the underside of the eye is blue/grey.

It has a long, narrow pterostigma (the coloured, sclerotized patch on the outer region of each wing).

Both sexes have black legs and pterostigma and a very broad base to the hind wing.

Without the pterostigma, self-exciting vibrations would set in on the wing after a certain critical speed, making gliding impossible.

Both genders have a red pterostigma.

The wing is apparently hyaline in coloration with a slight darkening of the pterostigma area.