This is one of the larger ensign wasps, with forewings up to about 7 millimeters long. It is distinguished from other species by the wide separation of the first and second sections of the coxa, the segment of the leg that attaches to the body. Its body is black in color with contrasting blue eyes. The abdominal petiole, the constricted stalk that holds the posterior section of the abdomen, or gaster, is attached high on the body. The gaster is laterally compressed and oval to nearly triangular in shape, held in a flaglike fashion and resembling an ensign, a characteristic of the family that inspired the common name ensign wasp.
I commonly find them around the house.
Evania appendigaster, also known as the blue-eyed ensign wasp, is a species of wasp in the family Evaniidae. Its native range is not known, but it likely originated in Asia. Today it occurs throughout the tropics and subtropics and in many temperate regions. As with the rest of its family, the blue-eyed ensign wasp is a parasitoid known for specializing on cockroach eggs.