[en] The eigenmode equation describing ballooning drift waves in toroidal plasmas is analyzed using the WKB method. Two branches of eigenmodes are identified. One is slab-like and the other is a new branch induced by the finite toroidicity. The slab-like eigenmodes correspond to unbounded states and experience finite shear damping. The toroidicity-induced eigenmodes, however, correspond to local quasibounded states with negligible shear damping. Both branches of eigenmodes may exist simultaneously. Corresponding analytical theories are also presented