**4. Conclusions**

Pesticide formulations would have a significant impact on the biological effect for the studied pesticides. Efficacy, knockdown effect and period of effectiveness protection can be affected by formulation of an insecticide. All these parameters are determinant in the design of an application program of insecticides, but in most cases are unknown by the user, the farmer, generating consequently that a greater number of applications are realized. This increases the impact on the environment and likely the costs associated with pest management.

On the other hand, when insecticide residue can be affected by formulation (both in the initial deposit and in its persistence), other parameters inherent to the active ingredient and the capacity of detection and quantification of the measurement technique may be mediating the real importance that the formulation may have on the behavior of the residue. In this chapter, the formulation was determinant in the residual pattern of acetamiprid, imidacloprid, and diazinon, but not for l-cyhalothrin. Future complementary works may focus on considering other interaction between variables such as relevance of the type and concentration of coformulants; fruit growth stage; climatic conditions and spraying method; and fruit or vegetable species, since all of them dynamically seem to affect in some degree the behavior of the insecticide residue generated. This in turn suggests that in some cases the estimation of preharvest intervals calculated for certain active ingredients may be affected by the formulation used in the baseline studies, generating the risk of an underestimation of that interval.

Therefore, when formulations of the same active ingredient are widely available, it is desirable to have independent declination curves of insecticide residue for at least those which differ drastically in type of coformulants or adjuvants and its concentration of active ingredient, considering that there is a risk of significant variations in the behavior of the residue.
