Several species of Dendroctonus (Coleop- tera: Scolytidae) have cuticular invaginations, or my- cangia, in the integument which are specialized for carrying specific symbiotic fungi. The mycangium of Dendroctonus adjunctus, located under a callus that surrounds the prothorax, has been recognized but the mycangial fungus has not yet been identified. Fungi from mycangia of Dendroctonus adjunctus were isolated and compared with Leptographium pyrinum and Ophiostoma adjuncti, two species of fungi known to be present in trees colonized by Dendroctonus ad- junctus. Fungi isolated from Dendroctonus adjunctus mycangia were determined to be morphologically and genetically identical to Leptographium pyrinu
