Diachasma ferrugineum (Gahan, 1915)
Figures of the closely related D. alloeum, as well as additional comments, can be found under the Diachasma page.
This species is nearly identical to Diachasma muliebre, but the sculpture of the petiole differs slightly (Muesebeck 1956). The West Coast species (muliebre) is thought to be thelytokous whereas ferrugineum is arrhenotokous, with normal production of males and females.
The ovipositor is distinctly longer than the body in Diachasma alloeum, and about equal in length to the body in ferrugineum and muliebre. However, this character needs to be more critically examined because of potential allometry problems associated with hosts (and resulting parasitoids) that vary considerably in size.