The oriental fruit moth, Grapholita (Cydia) molesta Busck (Lepidoptera: Tortricidae), is one of the most destructive and economically important pests of stone and pome fruits worldwide. Peach is considered to be the primary host of this moth, but apple and pear have become increasingly important as late season hosts in the past decades. In this study we used two G. molesta strains, one maintained in the laboratory for over 70-80 generations and the other for no more than 15, to study the effects of long-term rearing on some life-history traits. Larval development and adult performance were measured by growing the larvae on three main host plants (peach, apple and pear) in order to detect possible changes in host suitability. Results showed that long-term rearing did not significantly affect the selected life-history traits measured for the two oriental fruit moth strains, with the exception of larval survival. Furthermore, it was found that peach, apple and pear were similarly suitable as hosts for the two strains. Larval development, however, was faster on peach than on any other host. Thus, differences in host plant suitability across the three host plants seem to exist. These differences could explain to some extent, the distribution and performance of G. molesta populations in the field and the preference of oriental fruit moth for peach over apple and pear.