Tebufenozide has limited direct effects on simulated aquatic communities.

Area of Science:

• Environmental Science
• Ecotoxicology
• Microbial Ecology

Background:

• Insecticide use in forestry is shifting towards narrow-spectrum compounds to minimize non-target species harm.
• Insecticides like Tebufenozide, an ecdysone mimic, pose risks through direct toxicity or environmental breakdown, impacting non-target organisms and microbial communities.

Purpose of the Study:

• To investigate the non-target effects of Tebufenozide formulations (Mimic 240LV and Limit 240) on aquatic communities.
• To assess direct impacts on amphibian larvae (wood frog) and zooplankton.
• To evaluate effects on biofilm and phytoplanktonic microbial communities, considering toxicity and nutrient/carbon sourcing from insecticide breakdown.

Main Methods:

• Outdoor mesocosm experiment simulating aquatic environments.
• Monitoring of amphibian larvae (Rana sylvaticus) and zooplankton communities.
• Analysis of biofilm and phytoplanktonic microbial communities, including nutrient cycling and beta diversity.

Main Results:

• Limited direct negative effects observed on amphibian larvae and zooplankton communities.
• Small, non-significant shifts in biofilm microbial communities involved in nutrient cycling.
• Slightly increased beta diversity in plankton communities of insecticide-treated tanks, suggesting dispersion or dysbiosis.

Conclusions:

• Tebufenozide formulations showed limited direct negative impacts on key aquatic organisms.
• Subtle alterations in microbial community structure were detected, potentially indicating changes in ecosystem functions.
• Further research is warranted to fully understand the long-term ecological implications of Tebufenozide in aquatic environments.