Enveloper

Envelopers are a species of insect native to the Death World of Yanth. They have two sets of wings for flight, but their highly adhesive spray makes them truly deadly. Their webbing shoots forth from openings behind their forward mandibles, and can hit targets at far distances.

Natives have nicknamed them "stickyflies", and immediately attempt to shoot down any they see before the insects can fire their entangling webs. Once trapped, heavy-duty solvents and acids are often required to free anyone webbed.

Source

 * Dark Heresy (2nd Edition): Enemies Without (RPG), pg. 99