The wingspan is 52–69 mm. Adults are more nocturnal than most sphingids. Adults are on wing from June to September in eastern Canada. In New Jersey, there are two generations per year and there are four generations in Louisiana.
Fullard, James H. & Napoleone, Nadia (2001): Diel flight periodicity and the evolution of auditory defences in the Macrolepidoptera. Animal Behaviour62(2): 349–368. doi:10.1006/anbe.2001.1753PDF fulltext