Therefore, infestations are likely to increase in areas where cull potatoes are allowed to remain in the field following the harvesting of the spring crop. Larvae tunnel through potatoes, filling tunnels with excrement and webbing on which disease-causing fungi grow. Such potatoes are unsightly and of little food value. Larvae usually enter tubers near eyes, covering the small entrance holes with webs and excrement. Infestations are more evident a few days later when a pink coloration develops in the flesh around entrance holes.
More excrement also is present.
Life History - Potato tuberworms may overwinter as larvae or pupae in the soil or in potatoes that are not subjected to freezing temperatures. Cull dumps, storage houses, and cellars are all suitable hibernation sites. The weak-flying moths emerge in spring and dart from plant to plant when disturbed. They are most active at dusk and dawn. Eggs are usually deposited on rough surfaces such as potato tuber eyes or the hairy leaf undersurfaces.