Red postules on Field Maple
These small red postules on Field Maple (Acer campestre) are caused by the gall mite Aceria myriadeum. Each postule contains several of the mites.
Red postules on Sycamore
A very similar gall to the previous species. These small red postules found on Sycamore (Acer pseudoplatanus) are caused by the mite Aceria cephaloneus.
Postules on Field Maple
These postules on Field Maple are caused by the mite Aceria macrochela. The galls form close to the veins in the leaf as the photo shows.
Postules on Silver Maple
A similar gall to the above species this time occuring on Silver Maple (Acer saccharinum) and caused by the mite Vasates quadripedes.
Irregular shaped postules on Sycamore leaves
These galls on Sycamore are caused by the mite Aceria macroryncha.They can be more volcano like in shape than those shown in the photos.
Felt galls on Sycamore
These felt galls on Sycamore are caused by the mite Aceria pseudoplatani. These white erinea on the underside of the leaf house and feed the mites. They turn brown in colour later. The upperside of the leaf is marked with a slight bulge which will also turn brown later on.
All photos – Ashley Watson.
Adventures of a WildLife 