The adult female has a bandless proboscis, short, brown scales on the scutum, and B-shaped (when viewed from the side) markings on each abdominal tergite.

[1] After taking a blood meal, the female lays her eggs in areas that readily flood, where they hatch when inundated.

Larvae are found from April through September and adults from May through October in their central range.

[1] Aedes vexans is a known vector of Dirofilaria immitis (dog heartworm), myxomatosis (a deadly rabbit viral disease), and Tahyna virus, a seldom-diagnosed Bunyaviridae virus, which affects humans in Europe, causing a fever which disappears after 2 days, but afterward can cause encephalitis or meningitis.

[2] A. vexans exhibited significantly higher transmission rates of Zika virus than A. aegypti, and its wide geographic distribution, periodic extreme abundance, and aggressive human biting behavior increase its potential to serve as a Zika virus vector in northern latitudes outside the range of the primary vectors A. aegypti and A.