Ecyrus dasycerus.
 
 
 
Size: approx. 5 mm. Photo: 05/01/12, 10 pm.


This longhorned beetle is Ecyrus dasycerus. The second reference states: "Variable in size, and darker and lighter variants occur, but the combination of body shape and the dark, inverted arc-like marking at the elytral base is distinctive (though the mark is sometimes faint)." The small photo shows a different specimen found on 09/14/14. 
 

 
bug guide (this photo):
http://bugguide.net/node/view/636032
D. Yanega Field Guide to Northeastern Longhorned Beetles (Illinois Natural History Survey, 1996):
http://www.inhs.uiuc.edu/resources/index.php?action=list&id=%20439