Thiotricha nephelodesma is a moth of the Gelechiidae family. It was described by Meyrick in 1926. It is found on New Ireland. The wingspan is about 13 mm. The forewings are shining white with a moderate grey transverse fasciae in the middle and towards the apex, the costa and dorsum slenderly grey between these, the apex suffused grey, confluent on the costa with the second fascia. The hindwings are grey.