Elm leaf galls?

Hi folks

I've noticed that now most of my trees have leafed out fully that a couple of the Elms have got a lot of galls on their leaves (and some sitting only a couple feet away have none at all).

They've had galls before and I've read and been told that they wont do any real harm so just ignore them but.........they seem to have a lot more than previously. Some of the leaves are absolutely covered.

Is this anything to worry about and if it is can they be treated?

Having said that I don't want to spray the tree with chemicals for purely cosmetic reasons, only if it's health is threatened.

Regards

Richard

Some people seem to have an inordinate fear of insecticides. In this day & age, the ones on the market are not dangerous if used as directed & with respect. Insects & diseases that may only be cosmetic problems on a full size tree can weaken a bonsai. You need to spray your elms with a systemic insecticide. The one we currently use is acephate. Do NOT use imidacloprid (Bayer's Tree & Shrub Treatment). Elm leaf galls are caused by a mite, & imidacloprid makes mites worse.
Iris