I have recently stumbled upon the page https://www.zin.ru/animalia/coleoptera/eng/tceap220.htm
while searching for an ID to a specimen that looks pretty identical.

Aplastus pleratus is the name. Maybe?

Thanks to everyone for their efforts on this. Thinking it might be something other than the usual wireworm, I'll add more ecological info. It appeared on the ground at the base of a long-dead Ashe Juniper stump I was grubbing out in thin soil atop limestone on a hill slope, surrounded by many native prairie grasses such as Little Bluestem. I'm not sure whether the larva got to its position from beneath the juniper or if I knocked it there from beneath an uprooted clumpgrass. I'm in the valley of the Dry Frio River in extreme northern Uvalde County, near the county line with Real County, southwestern Texas, about 100 miles west of San Antonio. We're in the midst of a longterm drought here. I hope this may be useful someday to an expert trying to figure these out.

hope i remember this one

Why are you leaning more towards teneb? I guess finding out the species would be out of the question?