Effects of Butyl Stearate on Ovipositional and Olfactory Behaviours of Beet Armyworm

YANG Wenxue;XU Shaoyao;DU Wenping;XU Jun;ZHANG Longmei;YANG Fazhong;School of Science,Southwest Forestry University;

butyl stearate;;Spodoptera exigua;;oviposition;;olfactory behaviour;;Rosa chinensis;;repellency;;chemical mechanism

In order to study the effects of butyl stearate( BS) when rose powdery mildew induces the host to resist beet armyworms,the BS repellent activity towards olfactory and ovipositional behaviours of beet armyworms was explored using the methods of dual-choice bioassay and olfactory bioassay. When rose plants were treated with BS solution in ethanol at concentrations of 1 116,4 069,and 8 521 μg/m L,the ovipositional behaviour of beet armyworms was inhibited and the total number of eggs on the treated rose plants during three days decreased significantly compared with the control( ethanol). The repellent percentages were 28. 1%,62. 4%,and 53. 5%,respectively,according to the egg number. Likewise,the obvious inhibition could be found based on the number of egg clutches. The further bioassays elucidated that BS possessed the significantly inhibitory effect on the olfaction of the mated female moths and the repellent percentages were 31. 8%,42. 9%,42. 2% at the three concentrations,respectively. The results from the field tests also demonstrated that the oviposition of the females was inhibited by BS. The egg numbers on the BS-treated roses and on the control plants( treated with ethanol only) were 732. 5 and1 735. 5,and the repellent percentage was 40. 6%. Therefore,BS possesses significantly inhibitory effect on beet armyworms,and the important and potential application of BS in the non-pollution control of the insect can be presumed.