Biological effects of oxidized carbon nanomaterials (1D versus 2D) on Spodoptera frugiperda: material dimensionality influences on the insect development, performance and nutritional physiology.
In this work, we developed an integrative experimental design to investigate the long-term effects of two important classes of carbon nanomaterials with different dimensionalities (i.e., 1D oxidized multiwalled carbon nanotube, ox-MWCNT, and 2D graphene oxide, GO) on the development of the generalist insect Spodoptera frugiperda (Lepidoptera: Noctuidae). Insects are exciting in vivo biological models for investigating the impact of nanomaterials on nanobio-ecological interactions. S. frugiperda larvae were reared from egg hatching to pupation on diets containing ox-MWCNT and GO at different concentrations (0, 10, 100 and 1000 µg g-1 of dry mass of diet). Several aspects of larval and adult performance were measured under controlled conditions. The effects of the carbon nanomaterial (CNM)-containing diets on the nutritional physiology and digestive enzymatic activities of S. frugiperda larvae were also evaluated. The results showed that the type and concentration of CNMs in the diet negatively affected the reproductive parameters and the digestive and metabolic efficiency of S. frugiperda. The diet containing the highest concentration of GO significantly reduced the fecundity and fertility of S. frugiperda compared to the effects of other treatments. S. frugiperda larvae showed decreased efficiency of food conversion into biomass and maximal approximate digestibility when fed diets containing GO at higher concentrations. However, quantitative differences in digestive enzyme activities were not observed between all treatments. These findings highlighted the critical influence of CNM dimensionality on the general performance and nutritional physiology of the moth. This work contributes to the safety evaluation and future applications of CNMs in agri-environmental nanotechnology.