Parasitoids of Fruit-Infesting Tephritidae

Eupelmus

Members of the genus Eupelmus are notoriously polyphagous and several have been confirmed as facultative hyperparasitoids. At least three species have been reared from fruit infested with tephritid pests.

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).

1. Eupelmus sp. habitus: lateral... ↴

2. Eupelmus spermo... ↴

3. Eupelmus spermophilus habitus: latera... ↴

See Clausen et al. (1965).

No referenced distribution records have been added to the database for this OTU.

The three species noted above, E. afer, E. urozonus, and E. spermophilus were differentiated by Silvestri (1915), and the color differences used by Silvestri have been used by all subsequent authors to identify these three species in material reared from olives.

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.

Biological information on E. eurozonus was published as early as 1847 by Laure, and fairly detailed biologies were available as early as 1908 (Silvestri et al. 1908).

Use in classical biological control is limited because the best known species is a facultative hyperparasitoid, and one of the three species noted here (E. spermophilus), though reared from olives, may not actually attack olive fly, even facultatively.