Impact of the pesticide fipronil on honey quality and the survival of Apis mellifera bees.

Abstract

Fipronil is a widely used agricultural insecticide associated with the contamination of apiculture products and honeybee mortality. This study evaluated the presence of fipronil in honey samples from conventional and agroecological apiaries in Paraná, Brazil, and its toxic effects on Africanized Apis mellifera bees. Honey from four conventional apiaries showed fipronil levels above the maximum residue limit (0.05 µg mL^-1), while agroecological samples showed no detectable contamination. Toxicological tests revealed that ingestion was the most toxic exposure route (LC₅₀ = 0.74 µg mL^-1), followed by topical (LC₅₀ = 3.07 µg mL^-1) and indirect contact (LC₅₀ = 7.34 µg mL^-1). Fipronil exposure significantly reduced bee survival, with nearly 100% mortality after 120 h. However, no significant effects were observed on locomotion, flight, or acetylcholinesterase activity. The findings highlight the risks of fipronil to bee health and the quality of honey. The contamination of honey samples by the insecticide fipronil highlights the need for stricter regulations and sustainable agricultural practices. Agroecology emerges as a viable alternative to protect pollinators and ensure the sustainability of beekeeping.