Acronicta fallax, the green marvel, is a moth of the family Noctuidae. The species was first described by Gottlieb August Wilhelm Herrich-Schäffer in 1854.[1] It is found in most of North America, from Ontario, Quebec, New Brunswick, Nova Scotia, Newfoundland and Labrador and Manitoba south to Arizona and Florida.The wingspan is about 34 mm. Adults are on wing from February to November in Florida.