As can be seen, the key parameters in this control scheme are the roguing coefficient [sigma] and the impulse period T, that is, the parameters that are directly influenced by human decisions.
In the study presented in , the authors established a critical value of the impulse period that separates the system behavior into two cases.
If the impulse period is increased, a critical value [T.sub.0] [approximately equal to] 2.2736 is found, at which the pest-free response loses stability.
Following this approach, they also determined a threshold for the impulse period after which pest-free solutions lose stability.
Caption: Figure 2: (a) One-parameter continuation of the periodic response of system (14), with respect to the impulse period T.
Caption: Figure 3: Numerical continuation of periodic solutions of system (14) with pests and natural enemies coexisting in the ecosystem, computed for impulse period T = 6.
Caption: Figure 4: Numerical continuation of the periodic response of system (14) with respect to d and [[sigma].sub.x], computed for impulse period T = 6.