Eupelmus urozonus Dalman is thought to be exceptionally polyphagous. The biology of E. urozonus is well known. This species has received considerable attention in the olive-growing regions of southern Europe because it is sometimes the most frequently encountered parasitoid of olive fly, Bactrocera oleae (Rossi). Eupelmus urozonus is an ectoparasite, often of late instar larvae and sometimes of pupae. It can also develop as a hyperparasitoid of other olive fly parasitoids.
Eupelmus urozonus, along with the eulophid Pnigalio mediterraneus, was found to be one of the primary parasitoids of olive fly in Corfu, Greece, according to studies conducted in the early 1970’s (Pappas et al. 1977). However, the authors note that the presence of both parasitoids was not enough to produce long-term reduction in olive fly numbers. Eupelmus urozonus and E. afer Silvestri have been reared from cultivated and wild olives in South Africa (Neuenschwander 1982). Both are parasitic on olive fly and are very similar in appearance. Eupelmus spermophilus Silvestri is a third species of Eupelmus that has been recorded from cultivated olives from South Africa, possibly as a parasitoid of seed wasps. Eupelmus urozonus has also been reared from B. oleae in Jordan (Mustaf and Al-Zaghal 1987) and Crete, Greece (Bigler et al. 1986), and from Rhagoletis spp. infesting Berberis in Europe (Hoffmeister 1992).
Because of the wide host range reported for Eupelmus urozonus (see the on-line catalog of World Chalcidoidea by John Noyes), there is a possibility that cryptic species may be present. There is also a need to determine whether the three species that have been associated in some way with tephritid-infested fruit, E. urozonus, E. spermophilus, and E. afer, are truly distinctly different species.