Phenological phases of the host plant shape plant–treehopper interaction networks

Abstract

Abstract Several studies have recently focused on the structural pattern of plant–insect interaction networks. However, insects and plants have dynamic cycles and differ in their level of specialisation over time, space, and scales. Thus, it is expected that sap‐sucking insects, such as treehoppers, and plants will not share similar patterns of interactions in all phenological stages of the plants. It was postulated that phenological stages of the host plant could change the structure of plant–treehopper networks, which will be more specialised during the reproductive stage than during the vegetative stage, mainly because of high concentrations of toxic compounds in the flowers. Here, quantitative metrics derived from graph theory were used to describe, for the first time, the changes in the structure of plant–treehopper interactions during the phenological stages of the host plants in Brazilian Atlantic Forest. The results revealed high temporal turnover of plant–treehopper interactions, and high similarity in the treehopper composition between the phenological stages. In both phenological stages, plant–treehopper networks exhibited a modular and non‐nested pattern. However, during the reproductive stage, the results showed lower species richness of plants and treehoppers, and higher levels of network specialisation compared with the vegetative phase. These findings demonstrate that the organisation of the same ecological interaction can change throughout plant phenology. In short, it was shown that the phenological phases of the host plants can constitute a remarkable mechanism that shapes plant–treehopper interaction networks in a tropical rainforest.