Plant secondary metabolite increases the control-effectiveness of natural enemy - based on caffeine and Snellenius manilae

The food resources in the field can effectively strengthen the ability of natural enemies to control the pest. Certain compounds, in addition to carbohydrates and amino acids, may improve the physiological performance of insects. Caffeine, for instance, has been shown to enhance pollinator memory and physiological reactions. However, little is known about how caffeine influences parasitoids. The control effectiveness and survival rate of the parasitoid (Snellenius manilae) were tested in this study after the parasitoids were fed solutions with different concentrations of caffeine. We examined caffeine concentrations of 10-2, 10-4, and 10-6 (M) mixed with a 25% sucrose solution and a pure sucrose solution as a control group. The results show that a concentration of 10-6 caffeine solution significantly increased the parasitism rate of S. manilae by 10.76% when compared to the control group. Despite the significantly lower survival rate and male bias of S. manilae offspring in the 10-2 tre...田间食物资源可有效增强天敌控害能力。除碳水化合物与氨基酸外，部分化合物可改善昆虫的生理机能。例如，咖啡因已被证实可提升传粉昆虫的记忆能力与生理响应水平。但目前关于咖啡因对寄生蜂的影响机制仍知之甚少。本研究测试了螟蛉悬茧蜂（Snellenius manilae）取食不同浓度咖啡因溶液后的控害效能与存活率：实验设置的咖啡因浓度分别为10⁻²、10⁻⁴与10⁻⁶ M，均与25%蔗糖溶液混合；另以纯蔗糖溶液作为对照组。结果显示，与对照组相比，10⁻⁶ M浓度的咖啡因溶液可使螟蛉悬茧蜂（S. manilae）的寄生率显著提升10.76%。然而在10⁻²浓度组中，螟蛉悬茧蜂子代的存活率显著降低且呈现雄性偏倚（原文内容未完整呈现）