What characteristic is found exclusively on mosquitoes?

Scales on the wings is a characteristic that distinguishes mosquitoes from other insects. While many insects have wings, the presence of tiny, overlapping scales on the wings of mosquitoes is a defining feature that is not found in other groups of flying insects. These scales can help with insulation, flight stability, and can even play a role in the attractiveness of the insects to other species, including potential mates.

The elongated proboscis is common in many other insects as well, particularly those that feed on nectar or fluids, making it not exclusive to mosquitoes. Jointed legs are a general characteristic of arthropods, which includes numerous insect species. Wings without patterns can be found in various insect groups, so it's not a unique feature of mosquitoes. The unique presence of scales on the wings helps to identify mosquitoes and is critical in differentiating them from other insects.