Many eurytomids have an economic effect, both beneficial and detrimental. For example, certain Eurytoma spp. are problematic in stone fruit production due to feeding on the fruit pit, causing fruit loss. Zerova & Fursov (1991) detailed types of fruit attacked and relative infestation rates: Eurytoma amygdali Enderlein is a pest of almonds and can destroy up to 71% of almond fruits via their emergence from the seeds (Cakar 1980) while E. schreineri Schreiner can infest 65% of mature plum fruits (Puzanova-Malysheva 1930) Other genera of Eurytominae such as Tetramesa are destructive to wheat (Triticum sp.) (Phillips 1920, Knowlton & Janes 1933). Bruchophagus caraganae (Nik.) attacks seeds of Caragana arborescens Lam. (Fabaceae), an important windbreak tree in Canadian Provinces and infests 24.8 - 95.0% of the seeds (Hedlin 1956). Bruchophagus roddi Guss. is a seed pest of alfalfa (Medicago sp.) and causes 5-83% seed loss (Kolobova 1950) while B. kolobovae Fedoseeva and B. gibbus (Boheman) attack Lotus sp. and Medicago sp. seeds (Fabaceae). Interestingly, the graminaceous eurytomid galler Tetramesa tritici (Fitch) (the wheat jointworm) is parasitized by Eurytoma parva Phillips, and E. atripes Gahan attacks the Hessian fly, Mayetiola destructor (Say) (Malyshev 1968). Both have also been bred from the wheat stem sawfly, Cephus cinctus Norton (Bugbee 1967). Conversely, Rileya cecidomyiae Ashmead attacks a cecidomyiid midge responsible for deforming ornamental American holly (Ilex opaca) berries (Highland 1964). Macrorileya oecanthi Ashm. (pictured below) parasitizes eggs of the snowy tree cricket, Oecanthus niveus (De Geer), a minor pest of raspberries (Smith 1930).

Macrorileya oecanthi Ashmead