椰甲截脉姬小蜂对椰心叶甲及其寄主植物挥发物的行为反应

The Attraction of Volatiles from Coconut Heart Leaves Induced by Brontispa longissima to Asecodes hispinarum

采川Y型嗅觉仪，测定椰甲截脉姬小蜂（Asecodes hispinarum）雌成虫对离体0．72h未受害椰子心叶、不同头数为害的椰心叶甲（Brontispn longissima）幼虫-椰子心叶复合体、不同时间椰心叶甲幼虫-椰子心叶复合体、机械损伤心叶、成虫为害心叶、3龄幼虫-心叶复合体、3龄幼虫为害去虫叶、幼虫＋粪便及挥发物标样的行为反应．并对椰子挥发性化学物质作了GC—MS测定。结果表明：（1）离体0～72h未受害椰子心叶挥发物对椰甲截脉姬小蜂没有显著的引诱作用。（2）10、15、20头／叶3龄椰心叶甲幼虫为害24h后，幼虫-椰子心叶复合体挥发物对椰甲截脉姬小蜂有显著的吸引作用，其它为害头数的复合体对椰甲截脉姬小蜂没有显著的吸引作用。（3）10头3龄椰心叶甲幼虫为害20～48h．幼虫-椰子心叶复合体挥发物对椰甲截脉姬小蜂有屁著的吸引作用，其它受害时间吸引作用不显著。（4）受害椰子心叶去除幼虫和粪便前后．挥发物对该蜂的引诱作用没有显著差异；未受害心叶、机械损伤心叶、3龄幼虫和粪便对椰甲截脉姬小蜂没有显著的吸引作用。（5）GC—MS分析结果表明，3龄幼虫为害前后．椰子心叶挥发物的含量和成分发生了变化，受害后增加了4种成分：（E）-4，8-二甲基-1，3，7-壬三烯、未知物2、未知物3和苯甲酸乙酯4种物质。（6）椰子挥发物标准品（E）-4，8-二甲基-1，3,7-壬三烯在5×10-2μL/μL和5×10-3μL/μL浓度下，对椰甲截脉姬小蜂有显著的引诱作用，其它浓度对椰甲截脉姬小蜂没有显著的吸引作用。由此可见，椰子心叶受椰心叶甲为害后．诱导的挥发物质为椰甲截脉姬小蜂寻找寄主提供化学信息。

Using Y-type olfactometer, the behavior response of female Asecodes hispinarum to isolated undamaged cocos nucifera unopened leaves in 0-72 h, Brontispa longissima larvae-coconutun unopened leaf complexes infested with different numbers, B. longissima larvae-coconut unopened leaf complexes in different periods, meehanieally damaged unopened leaves, adults-unopened leaf complexes, third instar larvae-unopened leaf complexes, damaged unopened leaves （third instar larvae and fi＇ass removed 1 d after infestation）, third instar larvae and frass , volatile reference compounds were studied; and the chemical constituents in different unopened leaves were analyzed by GC-MS method. The results indicated that： 1） there were no significant behavior selection to the isolated undamaged unopened leaves for A. hispinarum in 0-72 h. 2） the attraction of volatiles from coconut unopened leaves complexes with 10, 15, 20 B. longissima 3rd larvae per leaf was significant to A. hispinarum after 24 h of infestation, but not lower or higher numbers. 3） The attraction of volatiles from the coconut unopened leaves complexes with 10 B. longissima 3rd larvae was significant to A. hispinarum between 20 h and 48 h after infestation, but not before or after. 4） No difference was observed in attraction of the female parasitoids to volatiles emitted from 3rd larvae- unopened leaf complexes and those from 3rd larvae-damaged unopened leaves （larvae and frass removed 1 d after infestation）. The female parasitoids were not attracted to the volatiles released from umtamaged unopened leaves, mechanically damaged unopened leaves, 3rd larvae and frass. 5） GC-MS results showed that after the unopened leaves were damaged by 3rd larvae, some components and contents changed, and the new chemicals were （E） -4,8-dimethyl-l,3,7-nonatriene, unknown 2, unknown 3 and Benzoic acid ethyl ester （CAS）; The female wasps were attracted by （E） -4,8-dimethyl-l,3,7-nonatriene at concentrations of 5×10-2μL/μL, and 5×10-3μL/μL, but not before or after. The results suggest that the volatile of B. longissima larvae-induced leaves may provide chemical information to A. hispinarum for the host search.