Eprinomectin from a sustained release formulation adversely affected dung breeding insects

Area of Science:

• Veterinary parasitology
• Environmental toxicology
• Insect ecology

Background:

• Parasiticide residues in livestock dung can affect non-target organisms.
• Eprinomectin is a common endectocide used in cattle.
• Understanding the environmental persistence and impact of eprinomectin is crucial for sustainable agriculture.

Purpose of the Study:

• To evaluate the insecticidal activity of eprinomectin residues in cattle dung.
• To present an improved method for extracting eprinomectin from dung.
• To assess the duration of eprinomectin's impact on dung-breeding insects.

Main Methods:

• Cattle were treated with a sustained-release eprinomectin formulation.
• Dung samples were collected at various intervals post-treatment (7 to 140 days).
• Emergent insect abundance, richness, and diversity were monitored; dung residues were chemically analyzed.

Main Results:

• Eprinomectin residues significantly reduced emergent insect abundance and richness across all sampling periods.
• Insect diversity was impacted for 84 to 112 days post-treatment.
• Eprinomectin was detected in dung at expected levels, persisting for up to 5 months.

Conclusions:

• Sustained-release eprinomectin formulations lead to long-term insecticidal activity in cattle dung.
• The observed reduction in insect emergence suggests potential non-target effects on pasture ecosystems.
• Further research is needed to understand the ecological consequences of these persistent residues.