Gordh, G., & Lacey, L. 1976 Biological studies of Plagiomerus diaspidis Crawford, a primary internal parasite of Diaspidid scale insects (Hymenoptera: Encyrtidae: Homoptera: Diaspididae).. Proceedings of the Entomological Society of Washington 78(2): 132-144.

Notes: Studies of Plagiomerus dispidis indicate that it is a solitary internal parasite of Diaspis echinocacti. When tested against third instar scales of six other species of diaspidid scale insects, the parasite was host specific.