Impact of mass-rearing on the host seeking behaviour and parasitism by the fruit fly parasitoid Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)

摘要

Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae) is a koinobiont larval–pupal endoparasitoid of a large number of tephritids. P. concolor can be commonly reared on fully grown Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) larvae. In our laboratory, over 180 consecutive generations have been completed on C. capitata. In this study, we tested the possibility that the uninterrupted mass-rearing of P. concolor on C. capitata may influence its host location and parasitisation behaviours when used against Bactrocera oleae (Rossi) (Diptera: Tephritidae), the fruit fly commonly targeted in mass release of P. concolor in olive-groves. Choice and no-choice tests were used with naïve and experienced P. concolor females exposed to B. oleae and/or C. capitata larvae. The study showed no significant difference in oviposition behaviours and host acceptance when provided either C. capitata or B. oleae. However, the study did show that experience on a host plus a substrate complex could influence host preferences, since females that had previous oviposition experience on a given host species searched and chose significantly more when the same host species was presented, both in choice and no-choice conditions. Therefore, within the context of the pest management of fruit flies, it could be very useful to incorporate procedures in insectary-propagated fruit fly parasitoids designed to provide adequate training (i.e. oviposition experience) on the fruit fly species needing to be controlled.