Abstract: Fumonisin B₁ has become a new environmental factor confronted by cotton bollworm because of the change of maize cultivation pattern. To clarify the adaptation of H. armigera to this new environmental factor, the growth and development of H. armigera and the activities of detoxification enzymes and antioxidant enzymes in H. armigera fed with fumonisin B₁ were determined. Fumonisin B₁ was fed continuously to the larvae since the third instar, the weight gain of the larvae in 7 days, the number of eggs laid, and the hatching rate decreased to varying degrees compared with the control group, and the developmental duration before pupation was shortened, while the pupal stage was prolonged. The lactonase activities of H. armigera were significantly increased, and the activities of cytochrome P450 and glutathione S-transferase varied in different degrees after different time of fumonisin B₁ stress. The activities of catalase (CAT) and superoxide dismutase (SOD) were significantly increased after fumonisin B₁ treatment for 1 day, while the activity of peroxidase (POD) was significantly increased only after 5 days of high fumonisin B₁ treatment. The activities of carboxylesterase, catalase, and peroxidase in the fumonisin B₁-resistant strain were significantly higher than those in the sensitive strain, increasing by 75.40%, 50.74%, and 117.21%, respectively. To sum up, the growth and development of H. armigera are affected by fumonisin B₁, and H. armigera responds to the stress of fumonisin B₁ by activating esterase, catalase and peroxidase.

Key words: Helicoverpa armigera, fumonisin B₁, growth and development, detoxification enzymes, antioxidase