角蜡蚧和日本龟蜡蚧蜡泌物的超微结构及化学成分分析

采用扫描电镜和气相色谱/质谱联用技术研究了角蜡Ceroplastes ceriferus (Fabricius) 和日本龟蜡蚧C. japonicus Green蜡泌物的超微结构及化学成分。结果表明,这2种蜡蚧分泌蜡质和形成蜡壳的过程基本相似。在1、2龄期分泌的蜡质为“干蜡”，蜡壳为星芒状，虫体周缘的蜡芒均为2大节，与其2个龄期发育相对应，每一个大节又分为若干小节。同时，虫体背面中央蜡质堆积成帽状，也分为均匀的多层。由此说明泌蜡过程具有节律性。虫体周缘与蜡芒对应的突起区上分布着密集的刻点状腺孔，每一个腺孔分泌1根蜡丝，这在以往玻片标本中是观察不到的。雌性第3龄幼虫和成虫期，虫体分泌“湿蜡”，形成龟背状蜡壳，泌蜡腺孔主要为三格腺和四格腺。在肛突区发现了密集的泌蜡腺孔，排列为纵条纹状。从角蜡蚧蜡泌物甲酯化处理样品中检测到14个组分，从直接测试 (未经甲酯化处理) 样品中检测到14个组分；而从日本龟蜡蚧则分别检测到10个组分和25个组分。它们的主要成分是一系列高级的长链饱和与不饱和的烃、脂肪酸、脂肪醇、酯类、醛类以及杂环、多环或大环状化合物。对它们可能的生物生态学功能进行了讨论。

Ultra-morphology and chemical composition of waxes secreted by two wax scale insects, Ceroplastes ceriferus (Fabricius) and C. Japonicus Green (Homoptera: Coccidae)

The ultra-morphology and chemical composition of waxes secreted by the scale insects, Ceroplastes ceriferus (Fabricius) and C. japonicus Green (Homoptera: Coccidae) were studied with the techniques of scanning electron microscope (SEM) and gas chromatography/ mass spectrometry (GC/MS). The results indicate that the two wax scale insects have a similar waxy secretion and wax test forming process. The scale insects in their first and second instars secreted dry wax that formed a star-shaped test. Every wax horn around the margin of the test consists of two segments. This is corresponding to the two developmental instars. Furthermore, each of the two segments of the wax horn included many sub-segments. Meanwhile, the wax accumulated into a cap-like structure with many layers on the dorsal region of the body. It was believed that some kind of rhythm existed in the wax secreting. A lot of striate punctures formed wax glands that are usually unable to be found with the slide specimens of the wax scale insects observed under the light microscopy. As the scales developed into the 3rd instar and adult stage, the wax secretion changed into “wet state" and formed a waxy test in tortoise shell shape. The wax glands on the dorsal surface mainly are trilocular and quadrilocular pores. Dense wax pores arranging in longitudinal strips also were found over the anal plates. The main chemical compositions of the wax secretions of the two scale insects were determined with GC/MS by the two methods of esterification and unesterification. For C. ceriferus, 14 and 14 compounds were determined from its wax secretion with the two methods respectively; while 10 and 25 compounds were determined respectively from the wax secretion of C. japonicus. The main compositions of their wax secretions include a series of long chain saturated and unsaturated hydrocarbons, fatty acids, fatty alcohol, esters, and some compounds with ring structures of multi-, macro-, or heterocyclic ring. Their biological functions were discussed.