Abstract: 　Objective To investigate the toxicity of alpha terthienyl to the larvae of Aedes albopictus , its influencing factors and effect on the larva deve lopment. Methods Under experimental ultraviolet A (UVA),the number of dead,pupal or eclosive mosquito larvae was determined on the condition of different doses of alpha terthienyl and different disposal time in the dark;the number of dead larvae was also determined under sunlight on the condition of different doses of alpha terthienyl and different disposal time to water. Results The LC 50 of alpha terthienyl to Aedes albopictus larvae was 2.37μg/L under UVA. The best effect was shown when the larvae were incubated with alpha terthienyl3 h in dark. Alpha terthienyl could significantly inhibit the larva deve lopment and the emergence of the pupae. Under strong sunlight, the larvae were quickly killed by high concentration alpha terthienyl. The 24 hours effect of alpha terthienyl was better when it was applied at 5AM than that of at 10AM and 1PM. Conclusion Alpha terthienyl is an effective, practicable larvicide which prohibits the growth and development of the larvae of Aedes albopictus .

Key words: Alpha-terthienyl, Aedes albopictus, Phototoxicity, Ultra-violent A(UVA)