巴氏新小绥螨对柑桔全爪螨处理的枳橙叶片挥发物的行为反应

【目的】研究巴氏新小绥螨Neoseiulus barkeri对柑桔全爪螨Panonychus citri及刺吸式昆虫为害柑桔叶片释放的挥发物的行为反应,揭示巴氏新小绥螨的嗅觉反应特点。【方法】采用GC-MS顶空进样法对枳橙叶片常见挥发性化合物、针刺枳橙叶片及其柑桔全爪螨雌成螨取食枳橙叶片挥发物进行定性分析,确定每类化合物的相对保留指数,构建枳橙叶片常见及受害挥发性化合物特征谱库。利用嗅觉测定技术分析巴氏新小绥螨对枳橙叶片挥发物的行为反应。【结果】针刺处理和柑桔全爪螨取食影响枳橙叶片挥发物的组成和含量。两种方法处理时枳橙叶片释放的主要物质为α-蒎烯、水芹烯、4-异丙基甲苯。随着处理加重,增量释放的物质为:cis-π-罗勒烯、月桂烯、柠檬烯、异松油烯,减量表达的物质为2-乙基-1-乙醇和十一烷。在10~(-2)、10~(-4)、10~(-6)和10~(-8)g/m L浓度下,正己醛、正壬醛、乙酸辛酯和正庚醛对巴氏新小绥螨有强烈的引诱作用(P>0.05);月桂烯在10~(-2)、10~(-4)和10~(-6)g/m L浓度下对巴氏新小绥螨有强烈的引诱作用(P>0.05);正壬醇和正辛醇随着浓度增加,对巴氏新小绥螨的引诱作用降低;苯甲醛对巴氏新小绥螨的引诱作用较弱。【结论】巴氏新小绥螨对柑桔全爪螨及刺吸式口器昆虫为害柑桔叶片释放出的挥发物各组分具有不同的行为反应,柑桔及其刺吸式害虫生境中的嗅觉线索在巴氏新小绥螨的寄主定位和生境选择中起着重要作用。

Behavioral response ofNeoseiulus barkeri to carrizo citrange leaves damaged byPanonychus citri and sucking insects

Objectives] To determine the olfactory response ofNeoseiulus barkeri to volatiles released by citrus leaves that had been damaged by eitherPanonychus citri or piercing-sucking insects.Methods] Common volatile compounds of citrus leave were qualitatively analyzed using GC-MS-liquid mass spectrometry. The relative retention index of each compound was determined and a library of the common citrus volatiles obtained constructed. In addition, volatiles from citrus leaves damaged byP. citri and sucking insects were collected and identified. Orientation responses ofN. barkeri to volatiles were studied using a Y-tube olfactometer.Results] Both the kinds, and the quantities, of volatiles from damaged leaves were notably different to those of the control. Furthermore, the volatiles from leaves damaged byP. citri were significantly different to those obtained from leaves damaged by sucking insects. Both kinds of damage induced citrus leaves to releaseα-pineine,α-phellandrene and p-cymene. Insect damage dramatically increased the quantities of some volatiles, includingcis-π-ocimene, myrcene, limonene and terpineol, but reduced that of others, including 2-ethyl-alcohol and Undecane.N. barkeri was obviously attracted to caproaldehyde, nonanal, octyl acetate, heptaldehyde and myrcene at the concentrations tested (P>0.05). It was less attracted when n-octanol and 1-nonanol concentrations decreased.Conclusion]N. barkeri have different behavioral responses to volatile components from citrus leaves damaged byP. citri compared to those damaged by piercing-sucking insects. Chemical cues induced bythe feeding activity ofP. citriand piercing-sucking insects play an important role in host selection and location byN. barkeri.