Thanks Brian looks like a good reference. Sanch now that I'm more experienced I'd probably add more texture, more details and try to make the beatle more 3-dimensional.
Brian my entymologist friend recommended also his latest book.
Art Evans, who has a new book on Beetles of the Eastern North America.
Evans, A.V.: Beetles of Eastern North America (eBook and Paperback).
Description of the book Beetles of Eastern North America by Evans, A.V., published by Princeton University Press