The 'Death Beetle' spawn in SOL B is rather rare. I've seen him once in probably two dozen trips, but I didn't specifically look for him each time.
He can easily be solo'd by a 49 plus paladin, with a root and heal technique, just have to be careful with adds. I can take him out at lvl 54 in about 90 seconds, and the black chitin dropped for us last night. Plate armor look is very nice for many classes. I think everyone but Iksar can wear these. The beetle spawns with the rest of the beetles in SOL B, next to the one that is in the little shallow cave.
-TerreFeu
54th Cavalier of Saryrn