Diachasmimorpha

The Indo-Australian group of species defined by the apically sinuate ovipositor includes some of the most important species used to date in tephritid biocontrol (namely Diachasmimorpha longicaudata and Diachasmimorpha tryoni). They have been widely distributed for biological control (Clausen 1978, Wharton and Gilstrap 1983, Ovruski et al. 2000), primarily as redistributions following their successful introduction to Hawaii.

Sixteen species have been reared from fruit-infesting Tephritidae, and known hosts for the genus are confined to the family Tephritidae. For more detailed information, see individual species pages.

occipital carina nearly always present laterally (e.g. Diachasmimorpha fullawayi, Figs. 2, 3), though varying in length and virtually absent in some species (e.g. Diachasmimorpha tryoni (Cameron) and Diachasmimorpha sanguinea (Ashmead)). labrum completely or almost completely concealed by clypeus (Fig. 5); outer surface of clypeus weakly and evenly convex; ventral margin thin and evenly convex to slightly sinuate throughout, rarely weakly bidentate medially. first flagellomere slightly longer than second, except in Diachasmimorpha carinata (Szépligeti). propleuron always without oblique carina dorsad propleural flange. Notauli deep to midpit (1, 2) and complete throughout in longicaudata species group (Figs. 7, 8), weak to absent posteriorly in all other species (Figs. 2, 3); always unsculptured. postpectal carina absent. hind tibia dorso-posteriorly without basal carina. fore wing (Fig. 9) with second submarginal cell (1, 2) short; m-cu arising distad 2RS. hind wing (Fig. 10) with RS absent basally, represented at most by a weak crease distally; m-cu long, nearly reaching wing margin, represented by a strong, pigmented crease. Second metasomal tergum striate in many species (Figs 4, 16), metasoma otherwise unsculptured beyond petiole. ovipositor long to very long, with double dorsal node subapically, distinctly serrate ventrally; ovipositor sinuate subapically in longicaudata species group (Fig. 13).

Diachasmimorpha_, as treated here, is best defined on the basis of the fore wing m-cu arising from a shortened second submarginal cell (1, 2), well-developed hind wing m-cu and 2M, loss of hind wing RS (at least basally), absence of oblique carina ventral-laterally on propleuron, unsculptured notauli, and the long ovipositor with strongly attenuate 0000410">hypopygium (Figs. 1, 2, 3). Of the known tephritid parasitoids, Diachasmimorpha is most similar in outward appearance to Doryctobracon. The species of Doryctobracon have the fore wing m-cu more basally displaced (arising from the first submarginal cell (1, 2) or directly in line with 2RS), the occipital carina uniformly absent, and the ventral margin of the clypeus weakly to strongly sinuate. The species of Fopius_, in addition to having the 0000351">fore wing m-cu as in Doryctobracon_, have sculptured notauli and an oblique carina on the 0000862">propleuron. Diachasmimorpha_, when treated in the strict sense, is clearly defined as monophyletic by the apically sinuate 0000679">ovipositor (Wharton 1987, 1988), and the Indo-Australian group of species to which this definition applies has been recognized as distinctive since the work of Fullaway (1951). Van Achterberg and Maetô (1990) considerably broadened the definition of Diachasmimorpha by including the North American species mellea Gahan and (by implication) other species that do not have a sinuate ovipositor. The most recent treatments (Wharton 1997, van Achterberg 1999) have accepted this broader concept for Diachasmimorpha.

Diachasmimorpha, as it is currently recognized and defined, includes species from the Nearctic and northern Neotropical Regions, the Indo-Australian Region (with at least two species extending northward into Japan and the southeastern corner of Russia), and the Afrotropical Region.

Synonym: Parasteres Fischer, 1967 (Wharton and Marsh 1978, as synonym of Biosteres; Wharton 1987, as synonym of Diachasmimorpha).

The type species of Parasteres is Biosteres (Parasteres) acidusae Fischer, 1967.

In many of the publications prior to 1988, the species of Diachasmimorpha were placed either in the genus Opius or in the genus Biosteres. Most of the species included here have been placed in the subgenus Chilotrichia of Biosteres by Fischer (1977, 1987).

Diachasmimorpha is a genus of the Opiinae subfamily of braconid parasitoid wasps and was first described in 1913. It is a small genus relatively restricted to the subtropics but also includes species in the Nearctic and northern Neotropical Regions. The genus is most clearly defined by an apical sinuate ovipositor, which is a synapomorphic character and defines a monophyletic lineage.