The mite species Eriophyes ilicis causes galls on the back of holm oak (Quercus ilex) leaves. These galls consist on a dent on the top side of the leaf and a rusty coloured stain on back that is made of a brush of anomalous, star like hairs.
Eriophyes ilicis may infest kermes oak (Quercus coccifera) as well.
Eriophyidae mites are minute animals which cause many galls in plants in which they live comfortably. Amongst family Eriophyidae, there is also E.tiliae that causes small red horns on top of lime trees (Tilia platyphyllos) leaves.
[photo Jordi Badia]