Stem borer (Coleoptera: Mordellidae) in Ambrosia

In 2022, I examined the stem of a side branch of the host and found it to contain a larva of this borer in the pith, along with an agromyzid puparium (record 0040) and approximately 12-15 larvae of a cecidomyiid (record 0667). The mordellid larva was a dull yellow color, with dorsal ampullae and a pair of minute urogomphi that were triangular in lateral view. The adult emerged through a small oval exit hole in the stem in spring. It was a grayish-black color with a uniform, silvery-golden pubescence covering most of the elytra. A note from my 2016 records that mentions a "beetle larva...inside the base of a side [branch], right where it connected to the main stem" is also tentatively placed here.