Plant Galls

Plant galls are something of an oddity when some folk first encounter them, others don’t even know they exist. Plant galls come in all shapes and sizes, and are formed by another organism using the plant as a host, using it for shelter and for food. The galls are caused by insects or mites, fungi or bacteria, and cause a biological reaction within the plant which causes these odd lumps and bumps to form of their tissues. They affect both herbaceous and wood plants, and there are at least over 1,000 species in Britain alone. It is most unlikely you would see the mite or insect which causes the majority of these galls for they are very small, some even microscopic, but the species can be identified by the galls they produce.The study of plant galls is called cecidology. Below the galls are aranged by host type.

Trees & Shrubs

Willow Redgall Sawfly Euura proxima
Willow Redgall Sawfly
Euura proxima
Marble Gall Andricus kollari
Oak Marble Gall Wasp
Andricus kollari
Cupped Spangle Gall Neuroterus tricolor
Cupped Spangle Gall
Neuroterus tricolor
Robin's Pincushion (Diplolepis rosae)
Robin’s Pincushion
Diplolepis rosae
Red Pustle Mite (Aceria aceriscampestris)
Red Pustle Mite
Aceria aceriscampestris
Aceria nalepai
Aceria nalepai
Cherry Aphid
Myzus (Myzus) cerasi
Euura pedunculi
Melampsora caprearum
Iteomyia capreae
Knopper Gall (Andricus quercuscalicis)
Knopper Oak Gall Wasp
Andricus quercuscalicis
Common Spangle Gall Neuroterus quercusbaccarum
Common Spangle Gall
Neuroterus quercusbaccarum
Aceria macrorhyncha
Aceria macrorhyncha
Aceria macrochela
Aceria macrochela
Red Nail Gall Mite
Eriophyes tiliae
Psyllopsis fraxini
Juniper Rust
Gymnosporangium sp.
Oak Apple Gall Wasp Biorhiza pallida
Cherry Gall Wasp (Cynips quercusfolii)
Cherry Gall Wasp
Cynips quercusfolii
Silk-Button Spangle Gall Neuroterus numismalis
Silk-Button Spangle Gall
Neuroterus numismalis
Artichoke Gall Andricus foecundatrix
Artichoke Gall Wasp
Andricus foecundatrix
Sycamore Felt Gall (Aceria pseudoplatani)
Sycamore Felt Gall
Aceria pseudoplatani
Alder Leaf Gall Mite
Eriophyes laevis
Poplar–buttercup Gall Aphid
Thecabius (Thecabius) affinis
Poplar Spiral Gall Aphid
Pemphigus spyrothecae
Pear Rust
Gymnosporangium sabinae

Herbaceous Plants & Ferns

Dasineura urticae
Dasineura urticae
Chirosia grossicauda
Chirosia grossicauda
Valerian Psyllid
Trioza centranthi
Xestophanes potentillae

For further reference see the links and literature below:

The British Plant Gall Society – To encourage and co-ordinate the study of plant galls, with particular reference to the British Isles.

Facebook British Plant Galls (in association with BPGS) – A group for sharing information about British and Irish Plant Galls.

Recommended reading: Britain’s Plant Galls: A Photographic Guide by Michael Chinery.