关键词: 光敏化杀虫剂琥红, 赤鲜红B, α-三噻吩, 白纹伊蚊, 幼虫控制, 毒理

Abstract:

Objective To assess the killing efficacy of three photosensitizers such as rose bengal(RB),erythrosin B andα-terthiophe to the fourth-instar larvae of Aedes albopictus in the laboratory and the field.Methods The number of dead larvae was recorded after application of RB,erythrosin B andα-terthiophen at different illumination conditions,and experimental parameters affecting photoinsecticidal was analyzed.The toxicity mechanism of RB,erythrosin B andα-terthiophen was studied by histochemistry method.Results RB,erythrosin B andα-terthiophen showed less activity in dark.The killing effect to larvae could reach 100%using 10 or 25μg/ml RB and 100 or 150μg/ml erythrosin B after exposed to 320×102lx of light intensity generated by daylight lamp(100 W)for 6 h.The killing effect ofα-terthiophen also achieved 100%at the concentration of 1μg/ml after exposure to moderate or low intensity sunlight for 5 h.Erythrosin B andα-terthiophen was applied to control Ae.albopictus larvae in the clear water o...更多r muddy water of the field respectively.The result showed the killing rates of RB andα-terthiophen were 46% and 49%in the muddy water body,and 67%and 89%in the clear water body.However,that ofα-terthiophen reached 98%in the above mentioned water body after continuously exposed to strong sunlight.Severe pathological damage of larvae caused by RB,erythrosin B andα-terthiophen were observed with optical microscopic.The damage were as follows:villus of midgut disappeared,midgut cells swell and cell nucleus disappeared.Fat body widely distributed under the epidermis and the shape of malpighian tubes was abnormal and its lumens narrowed.Conclusion RB,erythrosin B andα-terthiophen are high-efficiency and applied photo-insecticides.

Key words: Photoactivated insecticides rose bengal, erythrosin B, α-terthiophen, Aedes albopictus, Larva control, Toxicity