Effects of the polycyclic aromatic hydrocarbon anthracene on the survival of the semi-aquatic grasshopper Cornops aquaticum (Bruner, 1906): an experimental toxicological study

Introduction Environmental contamination by polycyclic aromatic hydrocarbons (PAHs) has increased in recent decades, intensifying the exposure of organisms in wetland ecosystems. Anthracene, due to its chemical stability and persistence, represents a potential risk to herbivorous insects associated with aquatic vegetation. Methods The toxicity of anthracene to the semi-aquatic grasshopper Cornops aquaticum (Bruner, 1906) was experimentally evaluated under controlled laboratory conditions using Eichhornia crassipes leaf fragments (49 cm 2 ) contaminated with increasing amounts (0.05, 0.10, and 0.20 g). Mortality, survival time, and bioaccumulation parameters, including daily uptake rate, were assessed. Results Anthracene exposure significantly reduced survival, confirming a dose-dependent toxic effect. A non-linear response was observed, with the 0.10 g treatment showing the most pronounced effect, resulting in only 10% survival at the end of the experiment. This pattern may be associated with reduced feeding or avoidance behavior at higher contamination levels. Sex-dependent differences were also identified: females exhibited greater tolerance at lower doses, whereas males showed higher survival at elevated concentrations. Body concentrations ranged from 0 to 4,022 μg g −1 , confirming effective uptake. Survival was more strongly associated with daily exposure rate than with total accumulated concentration, indicating a critical threshold between 450 and 550 μg g −1 day −1 . Discussion These findings demonstrate that exposure dynamics play a key role in anthracene toxicity and highlight Cornops aquaticum as highly sensitive to PAHs. The species shows strong potential as a bioindicator of organic contamination in wetland ecosystems, contributing to improved ecological risk assessment of persistent pollutants.