First, you need to collect males and females to start a breeding stock. Collect fruits of nectarine and peach infested by the Oriental fruit moth Grapholita molesta. Place them on a tray with soil in the bottom. The larvae once they finish the cycle, they pupate on the ground. Then place the pupae in a hatching cage to get the adults so that they can mate and lay eggs. The larvae can be raised in artificial diet as in the annexed article. Good luck.

https://www.academia.edu/21416903/Success_of_Grapholita_molesta_Busck_reared_on_the_diet_used_for_Cydia_pomonella_L._Lepidoptera_Tortricidae_sterile_insect_release

First, you need to collect males and females to start a breeding stock. Collect fruits of nectarine and peach infested by the Oriental fruit moth Grapholita molesta. Place them on a tray with soil in the bottom. The larvae once they finish the cycle, they pupate on the ground. Then place the pupae in a hatching cage to get the adults so that they can mate and lay eggs. The larvae can be raised in artificial diet as in the annexed article. Good luck.

https://www.academia.edu/21416903/Success_of_Grapholita_molesta_Busck_reared_on_the_diet_used_for_Cydia_pomonella_L._Lepidoptera_Tortricidae_sterile_insect_release

Yes I understand that, thank you for an advice.

Maybe I can try also to collect infesred peach twigs early in the season, because first generation larvae bore tunnels in tender twigs causing twig die-back, and put the twigs on the tray with soil?

Start by collecting larvae from small apples.

For rearing, see Vetter et al (1989) J. Econ. Entomol. 82(6): 1825-1829.