Avaliação do potencial biopesticida do óleo essencial da espécie Varronia curassavica Jacq. contra Drosophila suzukii (Matsumura, 1931), a mosca-das- asas-manchadas: abordagem in vivo e in silico

Abstract

Drosophila suzukii (Matsumura, 1931) is a global agricultural pest species. Theeconomic damage caused by D. suzukii resulted in approximately 500 million dollars inNorth America and European countries between 2010 and 2012. This species continuesto cause significant damage in agriculture worldwide, with Brazil one of the maintargets due to the large production of soft-shelled fruits, such as strawberries, blackberries, and grapes, the main host crops. The thesis was developed in threechapters, Chapter 1 consisted of a review of bioinformatics tools in developingpesticides against D. suzukii. Chapter 2 talks about the toxicological tests (in vivo) of the essential oils of Varronia curassavica Jacq. with the pest D. suzukii and its sublethal effects on non-target organisms. In Chapter 3, in silico studies to predict the possibleinteractions and mechanisms of action of the major constituents of the EOof V. curassavica Jacq. against the pest D. suzukii and non-target organisms. This studyaimed to evaluate the biopesticide potential of the major constituents of the essential oil (EO) of the species Varronia curassavica Jacq in controlling the pest Drosophilasuzukii, using in silico and in vivo methodologies. The data revealed in the GC-MSanalysis determined that shyobunol (23.61%) and α-cadinol (7.29%) were the majorityconstituents. In in vivo tests, the essential oil controlled (LC95 = 1.95 µL/mL) D. suzukii without killing or harming the species Apis melifera and the abilities of theladybug species to prey on aphids Rhopalosiphum padi (Linnaeus), suggesting that theconstituents from the EOs of V. curassavica Jacq. can be used as an alternative tool tocontrol D. suzukii. In silico tests, molecular modeling of the three-dimensional (3D) structures of crucial D. suzukii targets and non-target organisms (e.g., Acetylcholinesterase – AChE, GABAa Receptor and Octopamine Receptor) was carriedout by Swiss-Model and structures with values were selected of QMEANabove 0.5. Next, molecular coupling was performed using AutoDock 4 (version 4.2.6) withthemajority constituents, and the binding energies with the best values were classifiedandcompared with those of non-target organisms (e.g., Apis mellifera and Harmoniaaxyridis). Finally, Molecular Dynamics (MD) calculations were performed to evaluatethe stability of the EO constituents and compared with the analysis of the RMSDandRMSF graphs, in addition to the hydrogen bond, radius of gyration, and binding energygraphs.