Parornix torquillella is a moth of the Gracillariidae family. It is known from all of Europe, except Spain and parts of the Balkan Peninsula. The wingspan is 9–13 mm. The larvae feed on Prunus cerasus, Prunus domestica, Prunus insititia, Prunus maritima and Prunus spinosa. They mine the leaves of their host plant. The mine starts as a lower-surface epidermal gallery that widens into a blotch. In the end, it becomes a small, only weakly inflated tentiform mine. The lower epidermis is whitish, unfolded, and rather transparent. The leaf tissue is eaten up to the upper epidermis. The frass is deposited in a corner of the mine. In the end, the larva leaves the mine and lives freely under a leaf tip or margin that has been folded downwards, or in a leaf that is rolled into a pod.