There are two European species naturalized for control of the weed St.John's-wort (Hypericum perforatum), and you need male genitalia to separate them with certainty. C. quadrigemina seems to be the dominant sp. in N. America, though, and in it, both sexes are very brillant dorsally, while in C. hyperici, females are a bit opaque. … Boris Büche
Newburyport, MA