Phthorimaea operculella, also known as the potato tuber moth or tobacco splitworm, is a moth of the family Gelechiidae. It is an oligophagous insect that feeds on the plant family Solanaceae and is especially known for being a major pest of potato crops. Currently farmers utilize insecticides, parasites, and sprinkler irrigation in order to prevent P. operculella from infesting their croplands.

The Gelechiidae are a family of moths commonly referred to as twirler moths or gelechiid moths. They are the namesake family of the huge and little-studied superfamily Gelechioidea, and the family's taxonomy has been subject to considerable dispute. These are generally very small moths with narrow, fringed wings. The larvae of most species feed internally on various parts of their host plants, sometimes causing galls. Douglas-fir (Pseudotsuga) is a host plant common to many species of the family, particularly of the genus Chionodes, which as a result is more diverse in North America than usual for Gelechioidea.