Aedes vexans larvae have pecten
spines going to about the middle of the siphon, with 1-3 of the spines
more widely spaced than the others.
The saddle of segment
X on Aedes vexans does not completely encircle the segment,
but is close.
The antennae of Aedes vexans
has setae in the middle, and are not constricted.