Changing interactions among persistent species as the major driver of seasonal turnover in plant-caterpillar interactions.

Cintia Lepesqueur,Ivone R Diniz,Marcos C Vieira,Scheila Scherrer,Danielle M Salcido,Lee A Dyer,Mário Almeida-Neto,Martin Schädler

doi:10.1371/journal.pone.0203164

Abstract

β diversity of herbivorous insects in the tropics is usually very high, and there is often strong dissimilarity in herbivore species composition across different spatial scales and different abiotic gradients. Similarly, turnover is high for trophic interactions between herbivorous insects and their host plants. Two factors have been proposed to explain temporal or spatial differences in trophic interactions: changes in species composition and temporal changes in the behavior of shared species. The goal of this study was to evaluate determinants of high β diversity of trophic interactions between lepidopteran caterpillars and their host plants across dry and rainy seasons and their transitions. Over the course of a year, interaction diversity data were collected from 275 temporary plots in Cerrado vegetation, comprising 257 species of caterpillars, 137 species of host plants and 503 different trophic interactions. All these diversity parameters varied across seasons. Species assemblages of caterpillars and plants were different among the four seasons, and there was a high turnover of interactions between the seasons. The high temporal β diversity of trophic interactions was mostly due to interaction rewiring between co-occurring species, as opposed to changes in species composition over time.

Highlights

Plant-herbivore networks (PHNs) are sensitive to biotic and abiotic factors, such that a network encountered in any particular environment may be dramatically different from functionally similar networks found in other environments [1,2]
Species richness for caterpillars, host plants and trophic interactions varied over time (Table 1), and very few caterpillar species, plant species, and unique interactions were shared across all of the seasons
Interaction turnover can be decomposed into two components: the replacement of species between spatially or temporally different networks, and the replacement of interactions that occur between the species shared by those networks [2, 11]

Summary

Introduction

Plant-herbivore networks (PHNs) are sensitive to biotic and abiotic factors, such that a network encountered in any particular environment may be dramatically different from functionally similar networks found in other environments [1,2]. PHNs can vary through time due to habitat disturbance and ecological succession [2]. Another potential driver of temporal variation in PHNs is the phenological response of species to seasonal climatic variation. For instance, marked rainfall seasonality influences plant-herbivore interactions by altering patterns of reproduction and production of leaves and antiherbivore. Seasonal turnover in plant herbivore network structure. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

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