关键词: 白僵菌, 棉铃虫, 温、湿度, 致病力

Abstract: The pathogenicity of Beauveria bassiana to Helicoverpa armigera under different temperatures and humidities was studied in the laboratory. The 1～4instar larvae of the cotton bollworm were infected with different concentrations of B. bassiana under 10, 15, 20, 25 and 30℃ conditions. The results showed that under 25℃, the LT₅₀s of the larvae treated with three different concentrations of B. bassiana were the shortest， the larvae died most quickly and the mortalities were the highest. The LT₅₀s were prolonged as the ambient temperature turned-higher or lower than 25℃, and the larvae died slowly under these temperatures. There were significant differences among the mortalities of the cotton bollworm under different humidities. The larvae died most quickly and the mortality was the highest under 95% relative humidity, while the mortality decreased drastically under 70% relative humidity.

Key words: Beauveria bassiana, Helicoverpa armigera, temperature and humidity, pathogenicity