Learning of apple fruit biotypes by apple maggot flies

Previously, we showed that after a female apple maggot fly, Rhagoletis pomonella, arrives on a host hawthorn or apple fruit, its propensity to accept (bore into) or reject that fruit prior to egg deposition can be modified by previous ovipositional experience with one or the other species and, hence, involves learning. Here, we present both field and laboratory evidence indicating that females also are able to learn characteristics of three different apple biotypes or cultivars: "Early Macintosh," "Red Delicious," and "Golden Delicious." We suspect that females learn to discriminate among these three cultivars on the basis of differences in chemical stimuli among cultivars. The effect of fruit cultivar learning was not as strong as the effect of fruit species learning.