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Calathus - Calathus opaculus

Calathus - Calathus opaculus
Pulaski County, Kentucky, USA
October 8, 2002
Size: 9.5 mm
Calathus opaculus

Calathus opaculus vs gregarius
in KY is closest choice, but not so easy to resolve based on just above image. The "ideal" photograph of C. opaculus would show elytra more dull (no shininess) and with more distinct narrow pale lateral borders. Published keys also stress more distinct pale borders of the pronotum in C. opaculus but I find that character trait unreliable for distinguishing the pair. So Brad, when you scope the elytra do they show a very dull dark surface that contrasts with sharply defined lateral pale borders? Elytra in C. gregarius do reflect at least some shininess and the borders are not or indistinctly pale.

C. opaculus
Matches color of C. opaculus best IMHO. No shininess on elytra either.

Thanks for confirming C. opaculus!
Resolving difficult distinctions is so much more reliable with scoping than with a photographic image.

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