The carrying microorganism position and the structure of mycangium 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 spores carried by the mycangia of \%D. armandi\%, and they were inoculated into xylem of the host trees, while the b...