Egg laying behavior of Mediterranean fruit flies (Diptera: Tephritidae): Is social facilitation important?

In a set of three experiments, we were unable to verify earlier reports of social facilitation of oviposition-associated behavior in Mediterranean fruit flies, Ceratitis capitata (Wiedemann). In our first 2 experiments, we placed a focal fly on a kumquat (Experiment 1) or artificial fruit (Experiment 2) either occupied by an ovipositing resident fly or alone. The frequency of oviposition attempts by the focal fly was slightly, but not significantly, lower in the social than solitary case. In the third experiment, which was carried out in a large field enclosure, we found that focal flies did not prefer to alight on a kumquat occupied by an ovipositing fly compared with a similar but unoccupied kumquat. Our results suggest that social facilitation of oviposition-associated behavior may not be a ubiquitous phenomenon in medflies.