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...