Red horn structures

[dogsmercury]

Hello

i keep seeing these red horn structures on leaves everywhere, are they fungi, insects of part of the plant itself?



many thanks
Graham

[pleb]

The red structures are plant galls, Graham. They are actually made up of plant tissue and inside is often the larva of some insect (which gains protection from being in the gall). There is lots of information on Wikipedia and have a look at Google Images for other examples of plant galls.

[aeshna5]

I believe these particular galls are formed by mites.

[dogsmercury]

thank you both for your help

Graham

[poschiavanus]

Certainly mite galls. You don't mention what kind of plant these were on, but they have the look of Eriophyes tiliae which galls Lime Trees, and is known as the nail gall. However, there are several different types on lime, as well as a couple on Sycamore and one on Field Maple, which look fairly similar.