Impacts of Climatic Variability and Hurricanes on Caterpillar Diet Breadth and Plant-Herbivore Interaction Networks

Abstract

Climatic variability and meteorological extreme events are known to impact insect and plant populations, ecological processes, and ecosystem services. Available evidence suggests that variations in temperature and precipitation and extreme events such as hurricanes or acute droughts can affect nutrient cycling, species abundance and composition of biodiverse insect communities, the strength of species interactions, and the resilience of their networks. However, there is little information on how insects can respond and adapt to such environmental challenges, for example, by modifying their feeding habits and diet breadth, and thus their degree of specialization. In this chapter, we describe how the most abundant oligotrophic caterpillars of a tropical dry forest show variability in their diet breadths in an 11-year study period, as a function of interannual variation in climatic variables and the incidence of two hurricanes, influencing in turn the parameters of plant-herbivore interaction networks. We report that lepidopteran diet breadth was variable across years, and this variation is partially related to some climatic factors such the coefficient of variation in maximum temperature, variation in annual rainfall, and the duration of the preceding dry season. Plant-herbivore network parameters were affected by the same climatic variables, negatively influencing network size, specialization, and the number of compartments, while it positively affects the number of links per species. In addition, years with high variation in precipitation during the rainy season with high precipitation events promoted larger and more specialized networks. Regarding the impact of extreme meteorological events, herbivore’s diet breadth increased after the stroke of two hurricanes, increasing the number of links per species and network connectivity. In contrast, plant-herbivore network size, their specialization degree, and the number of compartments were negatively affected by these extreme events. Understanding the relationship between climatic variability and caterpillar diet breadth leads to open questions on the evolution of herbivore foraging behavior and phenotypic plasticity in plant host use and plant-herbivore network topology, influenced by climate and land use changes.KeywordsLepidopteranTropical dry forestsClimate changeHerbivore specializationPlasticity