Since you are in Maryland, you are lucky enough to have Dynastes tityus in some parts of your state. They are most active in your state through July, August, September, and October. You could check the stumps of rotted trees for larvae or even catch a female laying eggs there. Also, you could always set up lights or go to well lit shopping centers at night to look for them. As for the jewel scarab or any other type, I am not sure.