Natural history studies documenting spatial and temporal variation of species assemblages and their interactions are critical for understanding biodiversity and community ecology. We characterized caterpillar-parasitoid assemblages on shrubs in the genus Piper across remnants of semi-evergreen forest in the Yucatán Península during the rainy and rainy-dry seasons. We collected caterpillars feeding on Piper leaves and reared them to adults or parasitoids to: (i) describe tritrophic interactions between Piper, caterpillars, and parasitoids, (ii) compare empirical metanetworks among sites and seasons, and (iii) investigate patterns in species and interaction turnover across spatial and temporal scales to understand the contribution of species composition and interaction rewiring to overall interaction turnover. We found six Piper species supporting 79 species of caterpillars, which in turn hosted 20 species of parasitoids.In total, there were 116 realized trophic interactions. Species and interactions exhibited substantial turnover at temporal and spatial scales. Total interaction turnover was more pronounced across seasons in all sites (>93%), than it was between sites (<91%). We also found that interaction rewiring contributed more to overall interaction turnover than species turnover. The spatial and temporal variation in metanetworks documented here contribute to understanding fine-scale temporal and spatial turnover in tropical species and interactions and raise important questions about the lability of consumer specialization and the short-term effects of interaction rewiring on the stability of biotic communities. Our results highlight the importance of tropical food web studies that are based on natural history using consistent field methods to document bi-and tripartite interactions.
Insect herbivory can vary from an inconsequential biotic interaction to
a factor that contributes substantially to the diversity of plants and
animals and overall interaction diversity. As herbivory is the result of
numerous ecological and evolutionary processes, including complex
population dynamics and the evolution of plant defense, it has been
difficult to predict variation in herbivory across meaningful spatial
scales. In the present work, we characterize patterns of herbivory on
plants in a species rich and abundant tropical understory genus (Piper)
across forests spanning 44° of latitude in the Neotropics. We modeled
the effects of geography, climate, resource availability, and Piper
species richness on the median, dispersion, and skew of generalist and
specialist herbivory. By examining these multiple components of the
distribution of herbivory, we were able to determine factors that
increase biologically meaningful herbivory at the upper ends of the
distribution. Site level variables such as latitude, seasonality, and
maximum Piper richness explained variation in herbivory at the local
scale (plot level) better for assemblages of Piper congeners than for a
single species. Predictors that varied between local communities, such
as resource availability and diversity, best explained the distribution
of herbivory within sites, dampening broad patterns across latitude and
climate and demonstrating why generalizations about gradients in
herbivory have been elusive. The estimated population means, skew, and
dispersion of herbivory responded differently to abiotic and biotic
factors, illustrating the need for careful studies to explore
distributions of herbivory and their effects on forest diversity.
Nevertheless, we observed a roughly two-fold increase in median
herbivory in humid compared to seasonal forests, and this finding aligns
with the hypothesis that precipitation seasonality plays a critical role
in shaping interaction diversity within tropical ecosystems.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.