Modulating trophic interactions among natural enemies of Tuta absoluta in tomato crops using artificial sugary diets

Abstract: The tomato leafminer Tuta absoluta is a major pest in tomato crops worldwide. In
the Mediterranean, biological control relies on mirid predators like Macrolophus pygmaeus and Nesidiocoris tenuis, which target eggs but not larvae. In Catalonia, the parasitoids Necremnus tutae and Dolichogenidea gelechiidivoris dominate larval parasitism. Preserving these parasitoids is key to improving pest suppression. While interactions between N. tutae and mirids are well documented, those involving D. gelechiidivoris and M. pygmaeus remain unclear. This study examines how artificial sugary diets influence interactions between D. gelechiidivoris and M. pygmaeus, and their potential to mitigate damage by N. tenuis. Macrolophus pygmaeus showed high intraguild predation (IGP) on T. absoluta larvae parasitized for 72 h, but sugar supplementation significantly reduced this predation and enhanced parasitoid emergence. Additionally, high sugar levels suppressed N. tenuis without harming M. pygmaeus, reducing plant damage. These results show that artificial diets can modulate natural enemy interactions and enhance biological control in tomato crops.