کاهش جمعیت کفشدوزک هفت‌نقطه‌ای Coccinella septempunctata در مزارع گندم استان اردبیل در اثرکاربرد حشره‌کش‌های دلتامترین و فنیتروتیون

Wheat can be cultivated in many parts of the world due to its adaptability to different weather conditions. This strategic product, which has a special place in the human food basket, is attacked by various pests. While chemical insecticides are commonly used for pest control, their application can have detrimental effects on beneficial insects like the seven-spotted ladybird Coccinella septempunctata L., a natural predator of wheat pests. This study investigated the impact of deltamethrin and fenitrothion, which are among the recommended insecticides against wheat pests, on C. septempunctata population. A randomized complete block design with three treatments (fenitrothion, deltamethrin, and control) and four replicates was used under field conditions in Ardabil province, Iran. Larval populations were assessed one day before and 3, 7, and 14 days after insecticide application. Results revealed significant reductions in larval numbers following both insecticide treatments. Fenitrothion caused reductions of 72.83 %, 70.16 %, and 41.75 % in larval populations on days 3, 7, and 14, respectively, while deltamethrin resulted in reductions of 77.44 %, 72.02 %, and 58.66 % on the corresponding days. While deltamethrin exhibited a more pronounced negative impact on C. septempunctata larvae compared to fenitrothion, the overall effects of the two insecticides were not statistically different. Both insecticides were categorized as slightly harmful to C. septempunctata larvae throughout the assessment period. Therefore, the use of deltamethrin and fenitrothion during peak of C. septempunctata populations could potentially harm this beneficial predator and contribute to pest outbreaks. This approach can help conserve natural enemies, promote sustainable pest management practices, minimize the adverse environmental impacts of insecticide use, and preserve biodiversity in wheat agroecosystems.