After successfully combatting a pantry moth infestation, there will be no more moth eggs present, meaning the parasitic wasps can no longer rely on these as a source of food. This means that once the little helpers have completed their mission, they die and, due to their minute size, literally turn to dust. The ichneumon wasps have no interest in your food either. Once you are done using parasitic wasps, wipe down your cupboards thoroughly with a damp cloth. After this, there will be no traces left of either the parasitic wasps or the moth infestation.