[For full-size image, click this link...then click the image again after it loads in your browser window.]

An "occipital carina" is a fine ridge on the back of the head, encirling the area where neck attaches...see item labelled "16" in upper-left figure here, and also this image with an occipital carina and this one without such a carina.

Note that in both the photo above (see full-size image here) and the 1st photo of this series, there is no occipital ridge present. The same is true of the post below, identified as E. purgatus by the late ichneumonid expert Bob Carlson:

   

This does not jibe with the Key to genera of New World Ophioninae where in order to get to genus Enicospilus, one has to choose "Occipital carina dorsally present" in the first step of the key. (Going with "Occipital carina varying from broadly dorsally absent to completely absent" leads to genera that only occur south of Central Mexico.

For more details, see remarks under 1st image of this series.