Arista (insect anatomy)

In insect anatomy, the arista is a prominent, often bristle-like or plumose (feathery) appendage located on the antenna, typically arising from the last (or sometimes penultimate) antennal segment, the flagellum. The presence, absence, and morphology of the arista are important taxonomic characters, especially in the order Diptera (true flies). The arista may be sensitive to air currents and gravity, playing a role in flight control and orientation. In some fly species, it is believed to function as a sensory organ for detecting changes in air pressure, assisting in navigation and finding suitable habitats.