Leaf beetle herbivory shapes the subsequent flower-visiting insect community and impacts plant reproduction

Abstract

Herbivory can induce changes in flower traits influencing the community of flower-visiting insects and ultimately impacting the plant’s reproductive output. Here, we investigated how leaf herbivory on sweet pepper plants, Capsicum annuum L., by Diabrotica speciosa (Germar) adults influences the community of insect floral visitors and alters plant reproduction. In an experimental field, we found that flowers of herbivore-infested plants were less visited by insects than those of uninfested plants. A similar pattern was found for the abundance of the three most common species of floral visitors in the collections, Apis mellifera (Linnaeus), Toxomerus sp.1, and Trigona spinipes (Fabricius). The insect community associated with the flowers of herbivore-infested plants was distinct, less rich, and diverse than that of uninfested plants. Leaf herbivory also impacted flower abundance that likely influenced the visual attraction of insects. The changes in flower-visiting insect community associated with herbivore-infested plants coincided with a reduced number of fruits, which were smaller and contained fewer seeds than those from uninfested plants. Our results suggest that leaf herbivory by D. speciosa results in direct and indirect costs to the plants through modifications in abundance and composition of flower-visiting insect community.