In the West, Use Western Redbud

Q. Last Spring(2017) the leaves looked like they were being eaten.  Upon searching thoroughly, I couldn't see any creatures. Tree seemed to be losing some leaves early...some were speckled as shown in attached picture.  I thought the tree would die..Spring 2018...tree in full bloom (with exception of a few branches)...bees were loving it.  Now, it's back to  chewed leaves.  What can be done to establish a healthy tree again. Today, it was fed and watered with attached...what can be done to bring it back to good health.

Leafcutter bee circles in plant leaves. They are good guys.

This is Eastern Redbud. They cannot handle desert soils very well and certainly not rock mulch. Try to find Western Redbud. But use woodchip mulch and apply compost to the soil . Work it into the soil where the roots are.

Its okay but you need compost, soil amendment added to the soil to make it alive again.

Q. The first picture is leafcutter bee. I advocate to do nothing. They are vegetable pollinators primarily since they come out late.

http://xtremehorticulture.blogspot.com/2014/05/leafcutter-bee-perfect-circles-now-seen.html

http://xtremehorticulture.blogspot.com/2014/09/leaf-cutter-bees-destroying-leaves-on.html

As far as the plant health, this is EASTERN redbud. It doesn’t care for our desert soils much. If you put it in soil covered in surface rock mulch get rid of it and use woodchip mulch. Before you apply it, put about ½ bag of good compost like Viragrow’s Soil Pro and water it in. 

Next time you plant, use half and half soil from the hole and compost and then plant it as you water it in the soil making a slurry. Then cover the rootball area with woodchips and not rock. Eastern plants like Eastern soils. Next time try a Western Redbud. Likes our soils much better.

Check and make sure it is getting enough water each time its watered. Not frequency, how often it is applied, but amount of water.