I live in northwest New Mexico in the San Juan Basin where darkling beetles are very common. I've been doing a bit of research on beetle larvae, and considering how common darkling beetles are, that is my best guess as to what this is. I am interested to know what the larvae eat and if they live in or eat wood or woody veg.
Thank you for your help and for setting up this forum.
I agree with your identification, but tenebrionids are so diverse that I can't really generalize. Pretty sure most are scavengers on dried organic matter like the adults are (assuming you found this in an arid habitat). You might want to try finding a coleopterist (beetle expert) who specializes in darkling beetles to supply more detailed information. Thanks for sharing the link to the wonderful image!