Biological parameters of Muscidifurax raptorellus (Hymenoptera: Pteromalidae) on Bactrocera oleae (Diptera: Tephritidae), the key pest of olives

ABSTRACT The olive fruit fly, Bactrocera oleae, is one of the main pests of this crop and its control requires the development of methods environmentally safer than those used mostly nowadays, being biological control a possible alternative. Accordingly, the capacity of parasitisation and the biological parameters of Muscidifurax raptorellus, a generalist parasitoid of dipteran pupae, were evaluated on B. oleae at 25°C, 80% RH and a 16:08 h light/dark photoperiod. In a development assay, the rates of parasitism ranged 60% to 72% and the duration of the preimaginal period was between 17.0 and 18.5 days. The total mean number of adult wasps produced per pair in a reproduction assay was 50.7, with a mean daily production of 7 individuals and a mean rate of parasitism of 32.6%. The moment of maximum offspring production was estimated at 2.6 days after the beginning of the oviposition. The intrinsic rate of natural increase of M. raptorellus on B. oleae was 0.147, what determines a population doubling time of 4.7 days. The functional response was type II and the maximum attack rate in 24 h was 19.6 pupae. At host densities ranging 20–80 pupae per female, the number of adult wasps produced was around 20–22. The results obtained show the potential of M. raptorellus to be used for the biological control of B. oleae.