Fig 4.

Response of oviposition substrate preference to conditioning, measured on two sets of media: orange versus pineapple (generation 46) (a); apple versus tomato (generation 43) (b). “Conditioned to avoid pineapple” means that quinine was present in the pineapple medium offered in period 1. The proportion of eggs laid on the orange medium was averaged over periods 2 and 3; bars represent standard errors.