茶蚜龄期划分及各龄期形态特征的识别

Identification of the instar and morphological characteristics of Toxoptera aurantia Fonscolombe

【目的】明确茶蚜Toxoptera aurantia虫龄鉴别特征,为准确、快速识别茶蚜龄期提供理论基础。【方法】利用体式显微镜分别对两翅型茶蚜各龄期若蚜和成蚜的体长、体宽、头壳宽、触角长度、腹管长度、尾片长度和后足胫节长度7项指标进行测量。【结果】无翅型和有翅型茶蚜的7个指标在各虫龄中均存在差异。不同龄期无翅型茶蚜体长、后足胫节长度和有翅型茶蚜后足胫节长度在不同龄期若蚜和成蚜间存在部分重叠或无,可用于鉴定茶蚜虫龄。此外,翅基发育程度可用于区分3和4龄若蚜,触角节数可用于区分1和2龄若蚜与其他龄期蚜虫,尾片的外部形态特征可用于区分若蚜和成蚜。【结论】无翅型茶蚜的龄期鉴定主要依据其体长和后足胫节长度,而有翅型茶蚜的龄期鉴定主要依据其后足胫节长度,同时结合胸部翅基发育、不同龄期触角节数及尾片形态等,可准确识别两翅型不同龄期的茶蚜。

[Aim]To provide a theoretical basis for the accurate and rapid identification of the instars of Toxoptera aurantia.[Methods]Seven morphological indices of different instars nymph and adults of both morph from T.aurantia,including body length,body width,head width,antennae length,cornicle length,cauda length and hind tibia length,were measured using a stereo microscope.[Results]There were differences in each of the seven morphological indices measured among various instars of both apterous and alate T.aurantia.The body length and length of the hind tibia of apterous individuals,and the length of the hind tibia of the alate individuals showed either part,or no,overlap between different instars nymphs and adults,and therefore could distinguish the instars of both morphs of T.aurantia.In addition,the development of the wing base could be regarded as a diagnostic characteristic for differentiating the 3rd and 4th nymph instars of alate individuals.The number of antennal segments could be used as a diagnostic characteristic to differentiate the 1st and 2nd instars from other instars,and cauda shape could be used to differentiate between nymphs and adults.[Conclusion]Instars of T.aurantia could be accurately and quickly distinguished on the basis of body length and length of the hind tibia,in the case of apterous individuals,and on the basis of the length of the hind tibia,in the case of alate individuals,in combination with auxiliary characteristics such as the development of the wing base on thorax,number of antennal segments of different instars and cauda shape.