龟纹瓢虫对茶树挥发物的行为反应

Behaviour responses of Propylaea japonica to volatiles from tea plants

以洁净空气为对照,源于茶树的27个单一挥发物及其中芳樟醇、反-2-己烯醛和顺-3-己烯-1-醇的混合物和8个"绿叶组分"的混合物为味源,设10-6,10-4,10-2g/ml 3个剂量,用Y形嗅觉仪测定了这29种味源对龟纹瓢虫的引诱效应。结果表明:(1)当剂量是10-6g/ml时,选择烯丙基异硫氰酸酯的瓢虫数显著高于选择对照的(P<0.05);(2)当剂量是10-4g/ml时,选择芳樟醇、苯甲醛、水杨酸甲酯、正己醇、1-戊烯-3-醇、(+)-3-蒈烯和苯甲醇的瓢虫数分别高于选择对照的(P<0.05);(3)当剂量是10-2g/ml时,选择所有单一挥发物的瓢虫数分别与选择对照的瓢虫数的差异均未达显著水平;(4)龟纹瓢虫趋向2组混合物,其数量分别与趋向对照的数量差异不显著。分析认为,茶树挥发物对该瓢虫有引诱效应,其中苯甲醛和水杨酸甲酯等互利素的引诱效应更强;该瓢虫对信息物的趋向性存在着阈值,但高剂量信息素有抑制效应;不恰当的信息物组配不能引起该瓢虫显著趋性。可供信息物调控龟纹瓢虫行为的参考。

Using clean air as the control, and 27 single volatile components from tea plants and their partial mixture, i. e. the mixture of linalool, E -2-hexen-1-ol and Z -3-hexen-1-ol and the mixture of 8 green leaf volatiles as tested odor resources, at the dosages of 10^-6,10^-4and 10^-2 g/ml, the attraction of the 29 odor resources to Propylaea japonica was detected by Y-tube olfactometer. The results showed that： （1） when the tested dosage was 10^-6 g/ml, the number of ladybug choosing allyl isothiocyanate was significantly larger than the number choosing the control（ P 〈 0.05） ; （2） when the tested dosage was 10^-4 g/ml, the number choosing linalool, benzaldehyde, methyl salicylate, hexanol, 1-penten-3-ol, （ ＋ ）-3-caren and benzyl alcohol was significantly larger than the number choosing the control （ P 〈 0.05）, respectively; （3） when the tested dosage was 10^-2 g/ml, the difference between the number choosing anyone of the tested single volatile components and the number choosing the control did not reach the level of P 〈 0.05; （4） when the dosage was 10^-6,10^-4 or 10^-2 g/ml, the more ladybug chose the 2 groups of mixtures than those chose the control, respectively, but the difference between the number choosing the mixture and the number chosing the control did not reach the level of P 〈 0.05. It is considered that the ladybugs are attracted to the volatiles from tea plants, from which benzaldehyde and methyl salicylate have more attractive effect than the other components. There exist thresholds during the attractive process; however, the high dosage infochemicals reveal the depressing effect. The mixtures that composed of non-appropriate components or ingredients with non- proper ratios do not markedly allure the ladybug. Those may be referred in the aspect for infochemicals application to mediate the behaviour of the ladybug.