**4. Conclusions**

A broader understanding of the effects of insecticides on vectors of human pathogens is needed to support continuous efforts aimed at epidemic reductions. Every year, new disease outbreaks occur, such as the Zika epidemic outbreak in 2015 in South America and the increasing number of cases of Dengue infection worldwide. These outbreaks point out the fact that, despite causing high mosquito mortality, the sublethal effects mediated by insecticides on the behaviors and physiology of mosquitoes can also influence their transmission of pathogens. A large number of studies have suggested that insecticide resistance has modified the physiology, blood-feeding behavior, and reproduction of mosquitoes, and to some extent the dynamics of many diseases that vector mosquitoes can spread. The present comprehensive review and discussion on how unintentional selection for insecticide resistance can drive the overall transmission risks of pathogens by different heritable traits and mechanisms in mosquitoes could help us to better predict, understand, and mitigate common and unexpected epidemics like those that have occurred recently.

The effects of sublethal exposures, on the other hand, involve even more dynamic environmental and ecological interactions that are much less tractable and reproducible by studies when compared with the effects of insecticide resistance in terms of population genetic changes. Thus, even though numerous studies have been done on these sublethal effects, establishing comprehensive and predictable links between the effects of sublethal exposures and changes in vector competence is still a challenge. Therefore, the sublethal effects of insecticides on mosquito vector competence might still be considered a large research gap, with there being a long way to go before we can obtain a more comprehensive understanding of their effects and mechanisms.

**Author Contributions:** Conceptualization, F.A., E.E.O. and G.F.M.; First Draft Preparation, F.A.; Review and Editing, F.A., E.E.O. and G.F.M. All authors have read and agreed to the published version of the manuscript.

**Funding:** Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES—001), Conselho Nacional de Desenvolvimento Científico e Tecnológico—Brasil (CNPq—142205/2017-6 for FA; 404844/2018-9 and 301725/2019-5 for GFM; 308576/2018-7 and 427304/2018-0 for EEO), and Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Fapemig).

**Acknowledgments:** The authors thank the editorial board of *Insects* and the four anonymous reviewers for comments and suggestions that helped to improve this review.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the writing of the manuscript, or in the decision to publish the results.
