云南双蜡蚧蜡泌物的超微形态与化学成分

采用扫描电镜、红外光谱、气相色谱/质谱联用技术研究了云南双蜡蚧Dicyphococcus bigibbus Borchsenius（同翅目：蚧科）蜡泌物的超微结构和化学成分。结果发现：该虫的若虫与成虫分泌的蜡质从蜡腺排出初期均为湿蜡，在体外凝结形成质地稍硬而脆的玻璃状干蜡壳，蜡壳具有均匀脊和横层。幼期和雄性蜡壳小，船形，周缘带有蜡角，中央隆起。雌成虫蜡壳大，元宝形。蜡泌物的红外光谱吸收峰密集，峰型尖锐，种的特征明显。用红外光谱特征推断蜡泌物的主要基团和化学构成在GC/MS检测中得到印证。用甲酯化和非甲酯化两种处理方法检测证明，该虫蜡泌物主要成分是一系列高级的长链饱和与不饱和的烃、脂肪酸及酯类化合物。化合物的碳原子数从C₁₄～C₄₀，大部分为偶数个，特别是碳链长度在C₃₀～C₄₀的酯类化合物种类多，比例大。还将该蚧虫蜡泌物的特征与蚧科内近缘的蜡蚧属种类及瘤坚大球蚧、朝鲜毛球蚧、背刺毡蜡蚧、白蜡虫等作了对比，阐述了蜡泌物在蚧虫分类、系统学及防治中的意义。

Ultra-morphology and chemical composition of waxes secreted by the scale insect Dicyphococcus bigibbus (Homoptera:Coccidae)

The ultra-morphology and chemical composition of waxes secreted by the scale insect Dicyphococcus bigibbus Borchsenius (Homoptera: Coccidae) was studied with the techniques of scanning electron microscope (SEM), infrared absorption spectra (IS) and gas chromatography/mass spectrometry (GC/MS). The results indicate that the wax secretions are wet at first from the glands in both nymph and adult stages. Then they coagulated into dry and glassy wax test over the body surface. The wax test with a hard and fragile quality consists of many vertical pillar-like ridges with horizontal layer upon layer. The wax tests of the young nymphs and male scale insects are small, ship-shaped, central dorsal region elevated highly and with some wax fringes around the body margin. Female wax test is larger, v-shaped at its top. The infrared spectra of the wax secretion show the characteristics for species in sharp and dense peaks. The main chemical function groups and compositions of the wax secretion are conjectured based on its infrared absorption spectra, and verified with the results of GC/MS. Through esterification and unesterification, it is found that the waxes are composed of a series of greater molecular compounds,i.e., long chain saturated and unsaturated hydrocarbons, fatty acids and esters. Their carbon atom numbers mostly are even number and range from C_(14) to C_(40). The proportion of ester compound is greater especially than those with carbon atoms C_(30) to C_(40). The wax characteristics of this scale insect were compared with that of other species in the same family, Coccidae, e.g., Eulecanium gigantea, Didesmococcus koreanus, Eriopeltis festucae and Ericerus pela. The significances of the wax secretion for the classification, systematics and control of scale insects are discussed.