. . . . . . . . pest of potato attacks the tuber in both field and storage.

Potato tuber moth pest of potato attacks the tuber in both field and storage.
It is the most widely distributed potato insect in the world. It is usually found in warm climates for overwinter survival and is considered a subtropical pest. The moth or worm is considered the most serious pest of potatoes in tropical and subtropical regions.
Foliar injury in the field is due to the larvae (tuber worm) mining into leaflets, causing them to form transparent blisters, then move into stem tissue causing death.
PTM/PTW damage is yearlong as the PTM will continue to breed in storage and lay eggs which will hatch into PTW. The length of the life cycle will depend on the storage temperature.