How did this happen? Southern pine beetles have two entirely unrelated mycangial symbionts, Ceratocystiopsis ranaculosus (Ascomycota) and Entomocorticium sp A (Basidiomycota). The picture on right shows primary isolation plates and subcultures from the mycangia 6 individuals taken from one loblolly log. The top half had mycangia full of only the E. sp A, and the bottom C. ranaculosus. Several folks (e.g. Richard Hofstetter, Kier Klepzig, and others) have documented that the beetle has paired internal tube-shaped mycangia (location highlighted in red in picture on left), and each mycangium is typically filled with one or the other symbiont, but not both, and not anything else. So the mycangium is extremely specific to only two fungal species, but those fungi aren’t even remotely related! Did the signalling/filtering system of the mycangium begin with one fungus, and was secondarily hacked by another fungus? Or did the mycangium co-evolve simultaneously with two unrelated but both beneficial fungi sharing a common recognition system? Both are incredible scenarios. So, wtf?