The South American potato tuber moth, Andean potato tuber moth or tomato stemborer (Symmetrischema tangolias) is a moth of the Gelechiidae family. It is native to South America, but has become a pest worldwide. Records include North America, Australia and New Zealand. The wingspan is about 20 mm. The larvae are a pest on Solanum tuberosum. It attacks the tubers as well as the stems and leaves of the plant. Pupation takes place amongst the debris of the host plant.