([Denis & Schiffermüller], 1775)[Synonyms: cydoniella auctt.]
Wingspan 8-9 mm. This species, previously known in Britain as P. cydoniella, has recently been found to be P. hostis, a newly described species, after a comprehensive review of the Phyllonorycter blancardella group. It is now proposed that all references to P. cydoniella from Britain should be attributed to P. hostis. A local species, distributed mainly in the southern and south-eastern area of England. It is rather similar to P. blancardella, with which it shares foodplants, but is generally brighter and cleaner in appearance, with less dark scaling, and is often larger. The adults, like several related species, are bivoltine, flying in May and again in August. The larval foodplants are quince (Cydonia oblonga), as well as crab-apple (Malus sylvestris and sometimes other rosaceous trees. The mine is an underside, strongly creased blister, causing a distinct pucker in the upperside of the leaf.