Crepe Myrtle Trees Losing Leaves?

We recently planted some young crepe myrtles, they are only a couple feet tall. Two are losing leaves. We planted them with good soil and they did well for two weeks. We've had a lot of rain recently, but there isn't standing water around them. I did notice quite a few June bugs digging holes in the area where we packed dirt around them.

Any thoughts?

By Cathy S