Glyphosate-environmental variables interaction: How does it affect the parasite Chordodes nobilii?

Area of Science:

• Environmental toxicology
• Parasitology
• Ecotoxicology

Background:

• Glyphosate is a widely used herbicide with potential environmental impacts.
• Limited data exists on how environmental stressors influence glyphosate toxicity to non-target organisms.
• Gordiid parasites, like Chordodes nobilii, are sensitive to environmental changes, but combined stressor effects are unknown.

Purpose of the Study:

• To investigate the combined effects of temperature, pH, and exposure time on glyphosate toxicity to freshwater gordiid larvae (Chordodes nobilii).
• To assess how these environmental variables modify glyphosate's impact on larval infectivity.

Main Methods:

• Larvae were exposed to factorial combinations of glyphosate concentration, exposure time (24h, 48h), temperature (18°C, 23°C, 28°C), and pH (7, 8, 9).
• Larval infectivity was tested using Aedes aegyptii as hosts.
• Generalized Linear Mixed Models (GLMM) were used to analyze the interaction effects.

Main Results:

• Significant triple interactions between glyphosate, temperature, pH, and time were observed.
• Glyphosate toxicity varied, with reduced toxicity noted at 24h exposure, pH 7, and 23°C.
• A combination of glyphosate and 28°C slightly reduced infectivity compared to temperature alone.

Conclusions:

• Glyphosate's toxicity to C. nobilii larvae is significantly influenced by a combination of environmental factors.
• The findings highlight the need to consider environmental variability in ecotoxicological assessments.
• Potential implications for host-parasite dynamics and ecosystem function under climate change scenarios are discussed.
• C. nobilii larvae show potential as bioindicators for environmental stress.