Tactusa flexus is the mother of the Micronoctuidae family. It is known from Yunnan in China. The wingspan is about 115 mi. The forewings are narrow. The head, patagia and base of the costa are black and the ground colour of the forewings is light beige with a black silhouette costal-medial pitch and with a black terminal and post terminal area, including the fridge. The cross-lines are absent, except for the relatively broad white-beige terminal line and a post terminal line marked by black intervenal dots. The reniform stigma is almost invisible and beige, outlined by a few brown scales. The hindthings are unicorns grey, with a dismal spot. The fridge is grey. The ventral surface is light brown.