Stem borer (Coleoptera: Mordellidae) in Bromus

I found a larva in its tunnel in a culm of the host in mid-November. The culm had lodged at a point about 20cm above ground level, and the larva was located in the base of the culm below the lodging point, near ground level. I successfully overwintered the larva, and the adult emerged in spring, leaving behind a small oval exit hole in the culm. The adult was a more or less uniform reddish-brown color, not unlike adults of Mordellistena spp. I reared from other hosts, but it has not yet been identified beyond family level. This was my first record of a mordellid in a grass stem in the stem insect survey.