为明确茉莉酸甲酯(MeJA)诱导柿树(Diospyros kaki Linn.f.)挥发物成分的变化对蚧虫的天敌昆虫红点唇瓢虫(Chilocorus kuwanae Silvestri)吸引力的持续效应,应用3种剂量(20、100μL和200μL)的MeJA处理柿树,通过"Y"型嗅觉仪测试瓢虫的行为反应,并采用顶空收集和气质联用(GC/MS)分析挥发物的组成和相对含量。结果表明,MeJA可以诱导树体挥发物成分发生改变,对瓢虫产生吸引力,其持续效应可达1d以上。而不同剂量的处理组之间存在差异,高剂量组中萜烯类物质含量最多,在处理后3h瓢虫的趋性最强,相应的α-蒎烯含量高达34.05%。处理3～5d后吸引力显著下降,α-蒎烯等化合物的含量也逐渐减少。因此,茉莉酸甲酯的连续应用可以招引更多的瓢虫来控制蚧虫。
Observed and compared the morphological characters of various instars of Encyrtus sasakii Ishii parasitized in Eulecanium kuwanai Kanda. Microphotographs were taken of the bodies. Study shows that： Encyrtus sasakii Ishii reproduces annually and overwinters as pupa in their host. Besides the individual differences resulting from development, the 1st and 2nd instar larvae have long breath pedicles in the end of abdomen, and with the larva molting during development, the exuvia accumulate at the end of the body, form a hollow sac called caudal sac that cover the breath pedicle during 3rd and 4th instar larvae. The scutulis of females are yellow, and foreside of wings is light fumed with a dark blotch covered by dense black thick hairs. While the males are black brown, the wing is light in color without a dark blotch.
