无翅茶蚜对茶树挥发物的触角电生理和行为反应

分别使用昆虫触角电位仪(EAG)和四臂嗅觉仪,测定了无翅茶蚜Toxopteraaurantii Boyer对14种茶树挥发性化合物、14种挥发物中"绿叶气味"组成的混合物(GLV)、14种挥发物的混合物(ACB)、以及新鲜嫩叶、芽、嫩茎、成叶和茶蚜为害嫩叶(ADYL)的EAG反应和行为反应。ACB引出最大的EAG反应值,茶树挥发物主要组分Z-3-己烯-1-醇、E-2-己烯醛、n-己醇、水杨酸甲酯和苯甲醇也引起较大的EAG反应值。4种正常茶梢的器官也引出较大的EAG反应,以嫩叶最强、依次为芽、嫩茎和成叶。有趣的是ADYL引出弱的负的EAG值。用嗅觉仪进行的生物测定表明,嫩叶以及主要的茶梢挥发性成分乙酸-Z-3-己烯酯、水杨酸甲酯、E-2-己烯-1-醇和Z-3-己烯-1-醇等也具有较强引诱活性。研究显示无翅茶蚜可能利用茶梢挥发物作为利它素而寻觅适宜的取食场所,如茶树嫩梢。

EAG and behavioral responses of the wingless tea aphid Toxoptera aurantii (Homoptera: Aphididae) to tea plant volatiles

Electrophysiological and behavioral responses of the apterous tea aphid,Toxoptera aurantii Boyer,to fourteen synthetic volatiles identified from tea shoots,and their partial(GLV mixture) and full(ACB) blends,as well as fresh young tea leaves,buds,tender stems,adult tea leaves and tea aphid-damaged young leaves(ADYL),were studied by using an electroantennography(EAG) and a four-arm olfactometer.The full blend elicited the largest EAG responses.Major volatile components from the tea shoots,Z-3-hexen-1-ol,E-2-hexenal,n-hexanol,methyl salicylate and benzylalcohol,were strongly EAG active.All the tea tissue materials tested also elicited significant EAG responses,with the young tea leaf being the strongest,followed by bud,tender stem and adult tea leaf.Surprisingly,ADYL elicited a weakly negative EAG response.In the olfactory assays,the fresh and tender tea leaves,as well as the individual major volatile components from the tender shoots(EAG-active),e.g.Z-3-hexenyl acetate,methyl salicylate,E-2-hexen-1-ol,Z-3-hexen-1-ol,etc.were all attractive.This result might indicate that the apteral tea aphids may use tea shoot volatiles as kairomone to find their optimal feeding sites,i.e.fresh tender tea shoots.