I see that Zwick et al. (2013) and Epler (2010) noted that C. padi is strictly a Palaearctic species?
From Epler (2010) "Klausnitzer (1976) described C. neopadi from three specimens from Massachusetts collected in 1913; this species is only separable from the similar C. padi (L.) by the
male genitalia. Klausnitzer (2009) noted that C. padi is strictly a Palaearctic species; Tetrault (1967) stated that C. padi did not occur in North America."

Seems reasonable that our records be attributed to neopadi.

a much more recent source (1) that i consider to be very reliable and taxonomically up-to-date has padi listed, but no neopadi
Klausnitzer is of course the global scirtid authority, but he's also been producing sketchy new taxa every week for half a century and little revisionary work, so i'd rather refrain from changing anything at this point, until someone (Charlene?) takes charge and comes up with a well-grounded verdict based on ample material from both NA and Eurasia
Matt Gimmel has spent some time working on scirtids, hope he gets back to them some day... he is very thorough, meticulous and diligent, which is exactly what we need to make sense of the nearctic scirtid fauna

Thanks for these notes V! I haven't found any resources that would help me sort the matter (genitalia descriptions for each species). DNA work would likely provide some clarity... Hoping someone can work on nearctic scirtids in more detail.