Family EURYTOMIDAE
Introduction
The Eurytomidae is a medium-sized family, and is quite commonly collected, particularly the genus Eurytoma, whose species have a wide range of biologies and hosts. The majority of eurytomids are parasitic, although a large number are phytophagous, feeding on seeds or boring in stems (e.g. all Tetramesa and Systole species, many Eurytoma and Bruchophagus species). Parasitic species are often associated with hosts hidden in plant tissue, such as stem-borers, seed-eaters or gall-formers. Some species display a remarkable mixture of biologies. In these entomophytophagous species, larvae start their development as parasitoids, but after their host is consumed they complete their development by feeding on plant tissue. Other species are facultative hyperparasitoids, and often have a very broad host range.
Economic Importance. Eurytomidae are interesting among the Chalcidoidea because they may contain as many pest species as beneficial ones. The almond wasp, Eurytoma amygdali, is a key pest of almonds in the Palaearctic, some Tetramesa species are cereal pests, and certain Bruchophagus species may be pests of Leguminosae. However, some of the phytophagous species can be beneficial, e.g. Eurytoma attiva, which has been used successfully for the control of the weed black sage (Cordia macrostachia) in Mauritius. A few eurytomid parasitoids have been used in biological control programmes, but without noticeable success.
Distribution. Cosmopolitan.
Classification. Stage & Snelling (1986) divided the Eurytomidae into three subfamilies: Eurytominae, Rileyinae, and Heimbrinae. This classification was followed by Boucek (1988).
Important genera: Eurytoma, Bruchophagus, Sycophila, Systole.
Identification of Australian genera: Keys to Australasian genera are included in Boucek (1988).
Diagnosis
Pronotum large, rectangular, generally at least half the medial length of the mesoscutum and with prominent anterior corners. Dorsum of thorax generally with coarse setiferous punctures; if without such punctures then prepectus reduced to smaller than the size of the tegula. Gaster convex dorsally, non-collapsing. Body usually without metallic coloration or shine.
General References
Boucek, Z. 1988. Australasian Chalcidoidea (Hymenoptera). A biosystematic revision of genera of fourteen families, with a reclassification of species. London : CAB International 832 pp.
Stage, G.I. & Snelling, R.R. 1986. The subfamilies of Eurytomidae and systematics of the subfamily Heimbrinae (Hymenoptera: Chalcidoidea). Contributions in Science. Los Angeles 375: 1-17