Psyttalia ponerophaga (Hymenoptera: Braconidae) as a potential biological control agent of olive fruit fly Bactrocera oleae (Diptera: Tephritidae) in California

Abstract

The olive fruit fly, Bactrocera oleae (Rossi), is a newly invasive, significant threat to California's olive industry. As part of a classical biological control programme, Psyttalia ponerophaga (Silvestri) was imported to California from Pakistan and evaluated in quarantine. Biological parameters that would improve rearing and field-release protocols and permit comparisons to other olive fruit fly biological control agents were measured. Potential barriers to the successful establishment of P. ponerophaga, including the geographic origins of parasitoid and pest populations and constraints imposed by fruit size, were also evaluated as part of this investigation. Under insectary conditions, all larval stages except neonates were acceptable hosts. Provided a choice of host ages, the parasitoids' host-searching and oviposition preferences were a positive function of host age, with most offspring reared from hosts attacked as third instars. Immature developmental time was a negative function of tested temperatures, ranging from 25.5 to 12.4 days at 22 and 30 degrees C, respectively. Evaluation of adult longevity, at constant temperatures ranging from 15 to 34 degrees C, showed that P. ponerophaga had a broad tolerance of temperature, living from 3 to 34 days at 34 and 15 degrees C, respectively. Lifetime fecundity was 18.7 +/- 2.8 adult offspring per female, with most eggs deposited within 12 days after adult eclosion. Olive size affected parasitoid performance, with lower parasitism levels on hosts feeding in larger olives. The implications of these findings are discussed with respect to field manipulation and selection of parasitoid species for olive fruit fly biological control in California and worldwide.

Molecular characterization of Psyttalia lounsburyi, a candidate biocontrol agent of the olive fruit fly, and its Wolbachia symbionts as a pre-requisite for future intraspecific hybridization

“…Although one of the two variants was found in another Bactrocera species (Sun and Lin, unpublished), these variants had yet to be reported either in the B. oleae (Kounatidis et al 2009), or in phylogenetically related wasps used as candidate biocontrol agents (e.g. Billah et al 2008;Rugman-Jones et al 2009;Sime et al 2007;Sime et al 2006;Sime et al 2008). …”

Evaluation of Fopius arisanus as a biological control agent for the olive fruit fly in California

“…Among the favourable characteristics of F. arisanus as a parasitoid of B. oleae are its relatively long ovipositor compared with other parasitoids of B. oleae , and the fact that it usually oviposits into eggs. Both features may help it circumvent the difficulties that some larval parasitoids encounter when attacking B. oleae in larger olive cultivars (Sime et al , 2007; X. G. Wang, unpublished data). Although B. oleae eggs are deposited near the fruit surface, the larvae often burrow deeply into the pulp, where parasitoids with short ovipositors (which include several B. oleae specialists) cannot reach them.…”

“…Among the goals of the present study, therefore, was to acquire basic information on reproduction and oviposition behaviour that would allow the development of rearing methods that use B. oleae as the host. Several Psyttalia and Diachasmimorpha species (Hymenoptera: Braconidae) have recently been studied as biological control agents for B. oleae in California (Sime et al , 2006a, b, c, 2007; Daane et al , 2008), and this information will also permit evaluation of the potential performance of F. arisanus relative to other candidates.…”

Two new species of Psyttalia Walker (Hymenoptera, Braconidae, Opiinae) reared from fruit-infesting tephritid (Diptera) hosts in Kenya

“…A few species, notably P. efoveolata, P. inquirenda, P. somereni, and P. walkeri, have been reared only from fruits, with the host fl y unknown (Silvestri 1913;Fischer 1972a, b, c). Th ree of the species, P. dacicida, P. lounsburyi, and P. ponerophaga, are parasitoids of olive fl y, B. oleae (Silvestri 1912(Silvestri , 1913(Silvestri , 1916bCopeland et al 2004;Sime et al 2007;Daane et al 2008), and have thus far been recorded only from this host. Psyttalia concolor is also a parasitoid of B. oleae and was originally described from specimens reared from olives.…”