The potato tuber moth is a major pest of potatoes, and can also attack other crops of the Solanaceae family. As with all lepidopteran pests, the larval stages (caterpillars) are those that carry out the damage, They mine in leaves and stems, and in case of potatoes also in the tubers where they can further survive and multiply during storage. This is a big problem when the tubers are used as seeds, because the pest moves to re-infest or infest a field where there was no presence of the moth.
Life cycle of potato tuber moth
Adults deposit their eggs on the underside of leaves, or on the stem of the plant. In the case of potato, if there are still no leaves available, the females search for tubers through cracks in the soil where they oviposit near the eye buds of the potatoes. The eggs are spherical and pearly white in color. Before hatching they turn yellowish to brown. after the larvae emerge after 4-6 days. The larvae are white or light brown, with a brown head, and as they mature their coloration changes to pink or green; its larval cycle lasts from 13 to 33 days depending on the temperature and other conditions. Pupation takes place in the soil surface or in debris under the plant. The pupal stage lasts 10 to 33 days. The pupae have a yellowish or reddish-brown color, and are about 0.84 cm long. The adults, about one centimeter long, are pale brown with a dark mottled and thin body. The forewings have dark spots and both pairs of wings have fringed edges. The wingspan is 13-15 mm. Their lifespan is approximately 10 days.
The damage caused by the larvae is that of mines in the leaves and / or weakening of the stem, which can break. The feeding paths of the caterpillars in the tubers can only be detected when the potato is cut open. The galleries in the tubers makes then unsaleable and also facilitate the entry of pathogens. The most severe economic damages occurs when stored tuners are infested because the population develops quickly and all tubers become infested.