Evaluation of the effects of titanium dioxide and aluminum oxide nanoparticles through tarsal contact exposure in the model insect Oncopeltus fasciatus

Despite the increasing presence of metal nanoparticles in the biosphere as a consequence of their widespread use, knowledge about the impact of these nanoparticles on fauna, ecosystems and human health is far fromcompletion. This is especially true for terrestrial invertebrates. Insects are environmentally exposed to nanoparticles by several ways, the ectopic contact being one of the most probable. The model insect Oncopeltus fasciatus, has been used in the present work for testing toxicity of nanoparticles present in a surface. Adverse effects of TiO2 nanoparticles and Al2O3 in nanoparticulated or bulk form on mortality, reproductive and embryonic developmental parameters have been analyzed after tarsal contact of adult individuals of O. fasciatus. Effects were monitored in the unexposed filial generation from control and exposed adults. In order to know the effect of the nanoparticles on the insect composition, measurements of protein and lipid content as well as lipid peroxidation were also performed. The results obtained indicate that the ectopic exposure to nanoparticles at 1 mg/cm2 (TiO2) and 0.5 mg/cm2 (Al2O3) did not induce lethal toxicity in O. fasciatus, nor did itmodify any of the reproductive parameters. However, NPs-TiO2 and Al2O3 produced an increase in nymphal life span. In the parental generation NPs-TiO2 increased protein content whereas NPs-Al2O3 decreased it. Several effects were detected in the filial generation as consequence of parental exposure. NPs-Al2O3 decreased protein content, NPs-TiO2 decreased lipid content and Al2O3 in bulk form diminished protein content and increased lipid peroxidation. Responses observed in the individuals of the filial generation demonstrate the existence of trans-generational effects of NPs- Al2O3 and NPs-TiO2.