All the cases shown in this paper did not achieve the eradication
of dengue disease. Hence, the implementation of all optimal controls
analyzed in this paper is doomed to failure the task of eliminating
dengue transmission. However, optimal control as
mathematical results at least showed the relative amount of insecticide
and release of sterile insects must be introduced at different
costs. We can deal with optimal control problem by introducing a
strong constraint, that is, letting to the state variables assume fixed
values at the final time (should be fixed or not). By constraining the
values of the variables at the final time with the coordinates of the
small non-trivial equilibrium P3 , in such a way that the final values
are moved to the attracting region of the trivial equilibrium
point, then the dengue disease can be controlled. This situation
illustrates the optimal control forecasted mathematically that is
biologically acceptable as feasible implementation in order to
cease the dengue epidemics, which will be analyzed in a future
paper.