Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Photo#1604963
Tachys oblitus

Tachys oblitus
Chadds Ford, Delaware County, Pennsylvania, USA
May 13, 2017
Size: 2.53 mm.
This one I am not completely sure of. There is no key available that covers all of Pennsylvania's species. I adapted a key using Bousquet (2012) and Hayward (1900). I it doesn't include T. potomaca or T. rhodeanus as I can't get hold of the original descriptions or reference specimens. So, any suggestions or comments for this would be most welcomed.

Images of this individual: tag all
Tachys oblitus Tachys oblitus

I tentatively favor Tachys oblitus.
Similar dark T. pumilus is smaller (< 2.4 mm) and has pronotal m/s (microsculpture mesh) distinctly open among some other distinctions. Pronotal m/s in T. oblitus is striate under higher power which of course can't be confirmed by these photos.

 
If the options are T. oblitus
If the options are T. oblitus and T. pumilus then I would favor T. oblitus for both of the specimens that I have posted here. Sorry for the quality of the photos. It is really stretching the limits of what I am able to get with an iPhone with a little macro lens on it (I'm surprised that I can get any image at all with the tiny carabids). The micro sculpture on the pronotum on both specimens is striate, and similar to the micro sculpture on the elytra (as in Bousquet).

 
Okay --
you have it under control.