B型烟粉虱触角感受器的超微结构及对寄主植物气味的嗅觉行为反应

利用扫描电镜和透射电镜分别观测了烟粉虱触角感受器的分布、形态和结构。扫描电镜观察结果表明,烟粉虱触角由柄节、梗节和1～5节鞭节组成,绝大部分触角感受器分布在触角的背面、腹面和外侧面。雌、雄蛾触角上均存在5种感器,即微毛感器、锥形感器、刚毛感器、钟形感器和腔锥感器,各种感器在雌、雄蛾触角上的分布和数量没有明显的区别。除了微毛感器和刚毛感器的数量较多外,腔锥感器、锥形感器和钟形感器的数量均较少,分别为6、4和1个。透射电镜观察结果表明,烟粉虱触角上起嗅觉作用的锥形感器和腔锥感器均由表皮壁、鞘细胞和感觉神经元等结构组成。利用"Y型"嗅觉仪测定了烟粉虱雌虫对苘麻、棉花、烟草、黄瓜和甘蓝5种寄主植物气味的行为反应,结果显示,约30%的烟粉虱个体对气味源无反应,50%以上的个体对寄主植物具有显著的行为反应,对寄主植物的选择率差异显著,从大到小顺序为:黄瓜>苘麻>棉花>烟草>甘蓝。

Research on the ultrastructures of the antennal sensilla of Bemisia tabaci Gennadius and the olfactory behavioral actions to the odors of host plants

The morphology,especially the ultrastructures of antennal sensilla of B.tabaci was observed under scanning and transmission electron microscope.Antennae of B.tabaci are made up of scapus,pedicle and flagella that the latter consist of 1-5 segments and most of the antennal sensilla lie on its outer,upper and lower surfaces.Both the antennae of male and female contain five kinds of antennal sensilla,namely,microtrichia,chaetae sensilla,coeloconic sensilla,campaniform sensilla,basiconic sensilla,and the kinds,number and distribution of antennal sensilla of both sexes are similar.There have a large number of microtrichia and chaetae sensilla on the antenna of B.tabaci,and the number significantly higher than that of coeloconic,basiconic and campaniform sensilla,which was just 6,4 and 1,respectively.Coeloconic sensilla and basiconic sensilla,the main chemical odor receptors on antennae of B.tabaci,consist of cuticular wall,sheath cells,sensillum lymph and dendrites.The role of olfactory function in the host-selection behavior of B.tabaci was investigated by Y-tube olfactometer.The result indicated 30% of B.tabaci adults have no response to the odor of host plants,but more than 50% of adults show the strongest host preference to piemarker,cotton,tobacco,cucumber and cabbage.There was significant difference on the orientation rate among the five host plants,followed by the order:cucumber>piemarker>cotton>tobacco>cabbage.