The influence of age and experience on foraging behavior of Fopius carpomyiae, a parasitoid of ber fruit fly, Carpomyia vesuviana

Foraging parasitoids often adjust their foraging behavior according to the conditions they encounter. In this study the effects of age and experience on foraging and oviposition behaviors of Fopius carpomyiae Silvestri, was studied on ber fruit fly, Carpomyia vesuviana Costa. For this purpose, synchronous cohorts of F. carpomyiae were established in two age groups (7-8, and 12-13 days old). Then, the mated females (naïve females) in both ages were released individually into Petri dishes containing a ber fruit with a batch of eggs of ber fruit fly. Each female (n= 20) was observed continuously under a stereomicroscope while all distinguishable behavioral events of its foraging (the time of onset and duration) were recorded in the patch. In another experiment, the female wasps (7-8 days old), were exposed individually to a batch of host eggs on ber fruit flies, in the experimental patch for 24 h (experienced females). Results revealed that older females spent longer time in patches (5.48 min) compared with that of younger females (5.13 min). However, the average time of oviposition behavior (144.7±9.3 versus 146.4±8.9 s / female, respectively; P= 0.636) and percent parasitism (38.5±3.5 versus 39.2±3.2%, respectively; P= 0.84) were not significantly different between two age groups of female wasps. There was no significant difference in patch staying times of naïve and experienced females, nevertheless, the later allocated more time to ovipositing behavior and had significantly higher frequency and ratio of this behavior compared with those of former. In general, experienced females parasitized more host eggs compared to that of naïve females (46.5±2.8 versus 39.2±3.2%, parasitized eggs / female, respectively; P= 0.045)