Need help identifying Beetle. Northern Nevada.

Well, i dont really know. But Iberodorcadion lorquinii is from Spain and looks very similar.
There is a similar species in central Mexico also that hosts cactus...

Hi Anneguish,

As rjb said, this is the genus Moneilema, and I would determine it as the species M. semipunctatum. The coarse punctures on the pronotum, relatively smooth elytra, and antennae annulated with white all point to this species. The other species possible in the area would be M. annulatum, but that species has the pronotum more smooth, and the elytra are somewhat rugose, almost striate in some specimens.

They're flightless and the larvae feed in living cactus, while the adults can be found hiding on the plants during the day, or roaming on the ground when moving between host plants. The adults are mimics of the darkling beetles, like Eleodes sp. (Tenebrionidae), and when disturbed, will "head stand" like the darkling beetles to attempt to convince a predator that they possess defensive chemicals as the tenebs do, but it's all a ruse.

Cool beetles!!

Cheers!
Bandrow