Trichobaris trinotata, commonly known as the potato stalk borer, is a species of weevil in the family Curculionidae.

These are deposited singly in holes made in stems and leaf stalks by the insect's rostrum, or in the axils of terminal leaves.

The eggs hatch in about a week and the white, legless larvae eat their way through the stem tissues, creating tunnels up to 30 cm (12 in) in length.

[3] There is a single generation each year and the adults overwinter inside the dead potato haulms or the stems of other members of the Solanaceae such as Solanum carolinense.

[3] The adults feed on leaves producing ragged holes, but it is the larvae that cause most damage to the potato crop with their tunnelling activities.