The mycangium position and structure of the bark beetle Dendroctonus armandi.
The position and the structure of the mycangium (carrying microorganisms) of Dendroctonus armandi Tsai et Li, the most destructive bark beetle in Qinling and Bashan Mountains were studied. The results showed that the mycangia of the adult D. armandi consisted of the pronotal intergumentary cavities and spines, the spores of Leptographium terebrantis and Ophiostoma minus were the main species carried, and they were inoculated into xylem of the host trees, when the beetle infested healthy host trees. Because there were no specialized mycetocytes and structures for carrying fungi in the endobody of D. armandi, any hyphae specialized to form an appressorium or sucker structure in the fungi, and the fungi were attached to the alimentary canal of D. armandi. D. armandi was not dependent on the alimentary canal to carry and transport the fungi.