Eriophyes pyri is a tiny mite that causes galls to form on the leaves of Rowan and other members of the rose family, including cultivated pear trees. The gall is seen more often than the mite which causes domed pustules with openings, on both leaf surfaces - green/yellow at first but turning brown.
Phyllocoptes sorbeus is also found on Rowan, and is similar, but has a dense whitish, pinkish or yellowish felt-like erineum on the under- or upper-side of the leaf.
Good photos of both under- and upper-side of leaf are needed, showing presence of pustules with openings. The host plant should be noted in the Comments
On the leaves of Rowan and pear trees.
Galls are visible from late spring or summer until autumn.
The mites escape from the gall through pores on either side of the leaf to pass the winter in bark crevices.
Widespread and common in Britain.
Common in Leicestershire and Rutland.
Leicestershire & Rutland Map
Enter a town or village to see local records
Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015