Bifurcation diagram varying β
. The bifurcation diagram of varying β1, showing the attracting regions. With respect to the coordinates of small equilibrium point for all β1, the trivial is attractor for initial conditions in a very small region I (and Ia). Initial conditions in regions II and III are attracted to for , and initial conditions in regions IIa and IIIa are attracted to for . The scales of vertical and horizontal axes must be multiplied by the factors shown in the legends to obtain the actual values.