关键词: 苦皮藤素, 植物杀虫剂, 白纹伊蚊, 拒食活性

Abstract:

Objective　To study the mechanism of the toxicity of celangulin against Aedes albopictus larvae and its influence on various aspects, such as the growth and development of mosquito larvae. Methods　Conventional biological approaches were employed for determination of the toxicity and the impact on the larva growth and development: the changes in the gastrointestinal morphology were identified by HE staining; the antifeedant activity was measured through the colorimetric determination of chromium oxide. Results　With increasing concentrations, celangulin had strengthening toxicity against the fourth instar larvae of Ae. albopictus, with the LC₅₀ of 22.66 (18.38-27.95) mg/L and LC₉₅ of 84.51 (60.87-142.27) mg/L. Celangulin could reduce the pupation rate and extend the average pupation time and the average eclosion time of Ae. albopictus larvae, though it had no significant effect on the eclose rate. As the concentration of celangulin increased, its antifeedant activity became stronger, leading to gastrointestinal morphological changes: brush border loss and midgut degeneration and disintergration. Conclusion　Celangulin was able to kill Ae. albopictus larvae through gastrointestinal toxicity, antifeedant activity and contact toxicity, and inhibit their growth and development.

Key words: Celangulin, Plant pesticides, Aedes albopictus, Antifeedant activity