Insect Wing - Gliding

Gliding

Gliding is a form of flight, without the use of thrust. This form of flight is not common in insects, however there are a few species that do employ this unique ability. One of these includes some species of arboreal or tree dwelling ants, called Gliding ants (e.i., C. atratus, P. gracilis, C. heathi, D. armigerum, A. erinaceus). One of the most well known, and most studied, is the species is Cephalotes atratus. Rather than falling straight down however, the wingless tropical ant glides backwards as it falls, steering itself in a directed descent that lands it on the trunk of the tree; from which it fell—saving these insects from reaching the hostile and unfamiliar terrain of the forest floor. The ant uses its legs to slow its descent, then uses its elongated hind legs to steer their bodies while gliding, which rights itself early in their fall. However, all the legs are able to aid in the gliding process, shown in studies when removing certain legs.

These arboreal ants locate the tree to which they land on based on its color, attracted by white or more brightly colored trunks, which closely resemble their natural targets: lichen-covered tree trunks. The benefit of this is that the insect will avoid being lost amongst the forest floor, which is the location of many of its natural predators. Day-active ants that foraging in the lowland rain forest canopy are frequently exposed to predators, such as lizards, birds, anteaters, and disturbance (e.g., passing animals and wind) in tree crowns. If a worker ant happens to drop off from its safe haven, it will most likely land on unfamiliar vegetation or on leaf litter in the understory. Leaf litter along with the rest of the forest floor is a particularly complex foreign terrain and harbors a variety of predators that are not found in the canopy.

One of the only other examples known of insects gliding are found in arboreal bristletails (Archaeognatha), a kind of wingless arthropod. They were observed using the little barbs sticking out of their tails to guide their descent, thus increasing their chances of landing in a neighboring tree. When cutting these barbs off and dropped, the number of landings remarkably reduced.