What characteristic can be used to identify Aedes vexans?

Aedes vexans is a species of mosquito that is known for its distinctive coloration and patterning. The correct identification characteristic is that it is brown in color and has narrow rings of white scales on its body and legs. This specific coloration and pattern are key indicators when distinguishing Aedes vexans from other similar species of mosquitoes.

The option mentioning broad wings does not accurately describe Aedes vexans, as this species does not have the broad wing characteristic for identification. Instead, its wings are more typical of what is seen in mosquitoes, and it's the patterning on the body that is of greater significance.

While Aedes vexans may have some wing markings like many other species, identifying it solely by having four dark spots on the wings does not pinpoint this species specifically, as there are other species in the Aedes genus with different wing patterns. Additionally, the characteristic of being black with white scaling typically relates to other mosquito species, such as Aedes aegypti, which is more easily recognized by its stark black and white coloration.

In summary, the distinctive brown color combined with the specific feature of narrow rings of white scales is what uniquely identifies Aedes vexans and is crucial for correct classification in vector control efforts.