Rhabdopterus sp..
 
 
 
Photo: 04/14/18, 11 am.


Nice photo of a little leaf beetle. There are eight species of Rhabdopterus in the US, which favor plants including oak and hackberry (nettle tree) as their host. The small photo shows the same specimen. 
 

 
bug guide (these photos):
https://bugguide.net/node/view/1509566