Abstract:

This study aims to investigate the occurrence patterns of whiteflies in cotton fields in Shandong Province, to screen for highly effective and low-toxicity insecticides for controlling whiteflies in cotton, and to establish a scientific management strategy. Using a five-point diagonal sampling method, the population dynamics of whiteflies were systematically monitored across cotton fields with different planting dates to analyze its occurrence patterns. Five insecticides, including 17% flupyradifurone soluble concentrate (SL), were evaluated for efficacy against whiteflies in field trials conducted in accordance with the Guidelines for Pesticide Field Efficacy Trials. The field survey results from 2022 to 2023 showed that the occurrence pattern of whiteflies in cotton fields of the central Shandong region varied with planting dates. The initial occurrence was in late July, the peak was from early August to late September, and the highest peak occurred in late August, with whitefly activity continuing until the cotton leaves dropped during harvest. Field trials in 2024 showed that the flupyradifurone soluble solution was more effective in controlling whiteflies than other agents, followed by thiamethoxam. Additionally, lambda-cyhalothrin demonstrated a rapid effect against cotton whiteflies, and it is recommended to combine both agents for enhanced effectiveness. The control period for whiteflies in cotton fields of Shandong Province is from late July to mid-October. The preferred pesticide is flupyradifurone soluble solution, and the recommended dosage is 600 mL/hm² of the 17% flupyradifurone soluble solution. The results provide a scientific reference for the chemical control of whiteflies in cotton fields in Shandong Province.

Key words: whitefly, cotton, occurrence pattern, control, technical research