Effects of Experience on Oviposition and Attraction in Drosophila: Comparing Apples and Oranges

Adult Drosophila melanogaster were kept on a medium made from rotting oranges or apples. The oviposition behavior of these flies for the same media was tested in large lighted population cages. Flies showed a weak tendency to oviposit on the fruit type to which they had not been exposed, and counts of adults on the media also showed a negative association. In contrast, a second oviposition experiment with flies held in petri dishes revealed a strong positive association regardless of whether dishes were placed in the light or dark. The effect of experience on adult olfactory response was tested in a wind tunnel, and indicated that flies were slightly attracted to the medium to which they had not been exposed. These results indicate that the effect of experience depends on the paradigm used, and suggest that findings with one behavioral assay cannot necessarily be extrapolated to host responses in the field.