信息化合物在平腹小蜂寄主选择过程中的作用

Roles of infochemicals in host-selection process of Anastatus japonicus

利用“Y”型嗅觉仪研究了平腹小蜂对不同荔枝品种的离体叶片、活体植株、叶片挥发油和挥发物单个组分以及对荔枝蝽不同处理的的选择行为反应.结果表明,三月红和淮枝品种对平腹小蜂的引诱效果较好,而糯米糍、桂味、妃子笑和黑叶品种的作用不明显.作为荔枝叶片的主要挥发物组分,α-蛇麻烯和β-子丁香烯对平腹小蜂的引诱效果也不明显,但两者在天敌搜索寄主过程中表现为协同作用,并且当均以0.3μl.μl-1的浓度混合后,引诱效果最好.双向选择试验表明,平腹小蜂对荔枝蝽卵没有明显的趋性,而对荔枝蝽雌成虫及成虫腹末的水提液趋性较强.培养皿生测试验则表明,平腹小蜂在荔枝蝽卵样点处作出选择行为的数量和滞留次数最多,对荔枝蝽卵有较高的选择性.荔枝蝽成虫挥发物的主要组分(E)-2-己烯醛对平腹小蜂没有显著的引诱作用.

By using a Y-tube olfactometer, this paper studied the selection behavior＇ s responses of Anastatus japonicus to the volatiles ancl their individual components emitted from isolated leaves and live plants of different litchi varieties, and to Tessaratoma papillosa. The results showed that among the test litchi varieties, Sanyuehong and Huaizhi had more significant attracting effects to A. japonicus than Nuomici, Guiwei, Feizixiao and Heiye. The two main components of the volatiles from litchi leaves, α-humulene and β-caryophyllene, had no distinct attraction to A. japonicus, but displayed synergistic effect on the host-searching process of natural enemy. When the two components were mixed in equal concentration of 0.3 μl · μl^-1 , the attracting effect was most remarkable： In a dual-choice experiment, the selectivity of A. japonicus to T. papillosa eggs was not significant, but very remarkable to T. papillosa female adults and to the water extracts from adult abdomen-tip. In a vessel experiment, the numbers of A. japonicus which made selection to T. papillosa eggs and the settling frequency of A. japonicus on the place of T. papillosa eggs were more than those of other treatments. （E） -2-hexenal, one of the most important components of the volatiles of T. papillosa adult, didn＇t have evident attracting effect on the adults of A. japonicus.