Diachasma muliebre (Muesebeck, 1956)

Although currently placed in the genus Diachasma because of the shortened clypeus, Diachasma muliebre (Muesebeck) and two closely related species Diachasma alloeum (Muesebeck) and Diachasma ferrugineum (Gahan)] share many morphological and biological similarities with the New World species of the genus Diachasmimorpha (Wharton 1997).

Figures of the related species D. alloeum, as well as additional comments, can be found under the Diachasma page.

Taxonomic History / Nomenclature
This species was originally described in the genus Opius.
Diagnosis and Relationships
A key for distinguishing the three North American species of Diachasma that have been reared from Tephritidae is provided by Wharton and Marsh (1978).

Diachasma muliebre is nearly identical to Diachasma ferrugineum but the sculpture of the petiole differs slightly (Muesebeck 1956). The species from Western USA (muliebre) is apparently 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.

This and the other species of Diachasma superficially resemble Diachasmimorpha mellea, but mellea and muliebre can be readily distinguished by differences in the clypeus, which is short (broadly exposing the labrum) in D. muliebre.

D. muliebre has been found primarily in the western USA from Washington to California.
Biology / Hosts
Rhagoletis indifferens Curran in cherries