Hello,

You have a Camperdown elm tree, Ulmus glabra 'Camperdownii' The tree leaves appear to be damaged by the elm leafminer sawfly larvae feeding inside the leaves. It is too late this year to stop the damage.

Here is what you can do-

This fall you can use a soil drench insecticide of the systemic neonicotinoids imidacloprid (e.g. Merit, Xytect) or dinotefuran (e.g. Safari, Transect, Zylam). Or, the soil drench insecticide can be applied early next spring after the ground has thawed. It takes about 30 days for the soil drench to move through the tree.

Keep the tree watered this summer and fall if we have a period of no or little rain (anytime weather forecasts no rain for 14 days or more). Do not ‘drown’ the tree, water enough to moisten soil 6-8 inches down. Carefully dig down, timing your watering, to determine if you have watered enough the first time.

It would help the tree to move the stone mulch away from the trunk by 1-3 feet or more. Use chipped or shredded wood or pine needle mulch. Do not let mulch touch the trunk of the tree to reduce possibility of rotting the bark. 

The bark on the tree has some damage. The root flare at the base of the tree appears to be buried. The tree may benefit from excavating this root flare. A certified arborist can assess these concerns and advise you.

You can hire a certified arborist to examine the tree on site and give an overall health care plan. Find these professionals here by zip code search- http://www.treesaregood.org

Here are some bulletins with pictures and more information on sawfly—
https://bygl.osu.edu/node/698

https://bygl.osu.edu/node/1287

root flare information:

https://marylandgrows.umd.edu/2024/01/12/free-the-flare-maintain-visible-root-flare-for-tree-health/