绵粉蚧危害的花椒树对异色瓢虫的招引作用

The Bunge Prickly_Ash Tree Damaged by a Mealybug,Phenacoccus azaleae Attracting the Ladybug, Harmonia axyridis

1999— 2 0 0 1年研究了山西太行山区花椒林受绵粉蚧危害后 ,花椒树对主要天敌昆虫异色瓢虫的招引作用。结果显示 ,花椒树受害的新鲜枝梢对瓢虫的引诱率为 5 7 0 % ,未受害新鲜枝梢引诱率为 2 0 0 % ,用受害枝条水浴蒸馏出的馏分招引瓢虫的百分率为 37 0 % ,未受害枝条馏分招引瓢虫百分率为 10 3%。说明花椒绵粉蚧危害 ,可诱导树体挥发性物质发生改变 ,增加了对天敌昆虫的引诱作用 ,并且对瓢虫的引诱力随着受害枝梢量的增加而增强 ,它的诱导活性在受害后可持续约 2个月 ;采用GC MS联用仪分析比较 ,发现受害花椒枝梢的酯类物质明显增多 ,受害与未受害花椒枝梢的气相色谱图中有 15个峰位的化学组分相同 ,但受害的含量显著高。另有 9个峰位的组分在未受害枝梢中含量太低 ,未检测出。

Phenacoccus azaleae belonged to the family of Pseudcoccidae in Coccoidea. It is a new destructive pest in the Bunge Prickly_Ash forest, Zanthoxylum bungeanus in northern China. The host plant which was damaged attracting the natural enemy a ladybug, Harmonia axyridis was studied in Taihang Mountain Area of Shanxi Province during 1999—2001 The results showed as follow: The percentage of the numbers of the ladybug attracted to the damaged fresh twigs and leaves can reach 57 0%. Correspondingly, the percentage was 20 0% to the undamaged ones. The rates of the ladybug which were attracted to the extractive solution from the damaged twigs and leaves were 37 0%. However the rates of the check test only was 10 3%. The test results came to the conclusion that the volatiles of the host plant can be so greatly changed by the induction of the mealybug feeding that the attraction of the twigs and leaves was increased to the ladybug. And this kind of the volatiles could be extracted by hot water. Further more, the inductive activity released by the damaged host plant could persist for about two months after the mealybug stopped feeding. The inductive activities increased with the content of the damaged twigs and leaves in test. Through GC/MS analysis, it is found that some long chain ester compounds distinctly increased in damaged host tree. Some 15 kinds of the compounds are same between undamaged and damaged trees. However the contents are much higher in damaged host tree. Other new compounds are synthesized in the damaged host tree. Theses compounds might play the role to attract the natural enemies.