Efeito de nanopartículas de óxido de cério (CeO2), zinco (ZnO) e cobre (CuO) sobre características biológicas da broca-do-café Hypothenemus hampei (Ferrari, 1867) (Coleoptera: Curculionidae: Scolytinae)

Abstract

Among the most important pests in the coffee crop, there is the coffee berry borer Hypothenemus hampei Ferrari (Coleoptera: Curculionidae: Scolytinae) which is difficult to control, since it is protected inside the seed. The control of this pest is carried out mainly by the chemical method, however, the registered synthetic insecticides have not presented adequate performance and, therefore, it is important to search for new technologies for its control. In this context, the use of nanotechnology can improve the control of the coffee berry borer, since nanoformulations have been successfully tested as nanoinsecticides for pests of other crops, and also as nanofungicides and nanofertilizers in coffee crops. Thus, the aim of the present work was to address the current knowledge regarding the use of nanoparticles (NPs) as insecticides and, additionally, to evaluate the effect of NPs of three metal oxides in two different sizes (ZnO 20 and 60 nm, CuO 25 and 40 nm and CeO2 at 25 and 70 nm) on biological characteristics of the coffee berry borer. Topical, ingestion and ovicide toxicity, as well as repellency, were evaluated. In most of the studies carried out with insects it was found that the NPs of Au, Ag, Cu, SiO2, ZnO and Al2O3 are the most studied, and most cause toxicity through the release reactive oxygen species that interact with the biomolecules, producing oxidative stress in the insect's body. Regarding the effect of NPs on the coffee berry borer, it was found that there was no effect on survival after topical contact and ingestion, as well as the ovicidal effect. However, there was a sublethal effect in relation to the intake of artificial diet contaminated with NPs by reducing the oviposition of females exposed to diets with NPs of ZnO (20 and 60 nm), CuO (40 nm) and CeO2 (25 nm). The effect of NPs repellency on H. hampei was found for ZnO NPs (60 nm), in which there was a low percentage of insects boring into the fruits, and for ZnO NPs (20 nm), in which there was a lower percentage of bored fruits. This is the first work that involves the use of NPs to control the coffee berry borer, with an indication of a sublethal effect and that further studies are needed.