In NC, this species flies only in the springtime, mainly in the coastal plain and sandhills. They can be common where they occur and they can be seen perching obliquely on stems as shown below.
Mantled Baskettail (Epitheca semiaquea) Sampson Co., NC 25 March 2007
Mantled Baskettail (Epitheca semiaquea) Weymouth Woods, Moore Co., NC 10 April 2004