[excerpt] When Townes and Townes (1959) revised the genus Triclistus along with the rest of the Nearctic Metopiinae, they decided not to describe what was thought likely to be an additional new species, because only one male specimen was known. More recently, additional specimens, both males and females, were collected. From the females, which are even more distinctive than the males, it was easily seen that the species described below is indeed a new one.
Carlson, R. W.
"A New Nearctic Triclistus (Hymenoptera: Ichneumonidae),"
The Great Lakes Entomologist, vol 1
Available at: https://scholar.valpo.edu/tgle/vol1/iss1/5