DOI: 10.5061/dryad.8985578
title: Data from: Mycorrhizae alter toxin sequestration and performance of two specialist herbivores

description: Multitrophic species interactions are shaped by both top-down and
 bottom-up factors. Belowground symbionts of plants, such as arbuscular
 mycorrhizal fungi (AMF), can alter the strength of these forces by
 altering plant phenotype. For example, AMF-mediated changes in foliar
 toxin and nutrient concentrations may influence herbivore growth and
 fecundity. In addition, many specialist herbivores sequester toxins from
 their host plants to resist natural enemies, and the extent of
 sequestration varies with host plant secondary chemistry. Therefore, by
 altering plant phenotype, AMF may affect both herbivore performance and
 their resistance to natural enemies. We examined how inoculation of plants
 with AMF influences toxin sequestration and performance of two specialist
 herbivores feeding upon four milkweed species (Asclepias incarnata, A.
 curassavica, A. latifolia, A. syriaca). We raised aphids (Aphis nerii) and
 caterpillars (Danaus plexippus) on plants for six days in a fully
 factorial manipulation of milkweed species and level of AMF inoculation
 (zero, medium, and high). We then assessed aphid and caterpillar
 sequestration of toxins (cardenolides) and performance, and measured
 defensive and nutritive traits of control plants. Aphids and caterpillars
 sequestered higher concentrations of cardenolides from plants inoculated
 with AMF across all milkweed species. Aphid per capita growth rates and
 aphid body mass varied nonlinearly with increasing AMF inoculum
 availability; across all milkweed species, aphids had the lowest
 performance under medium levels of AMF availability and highest
 performance under high AMF availability. In contrast, caterpillar survival
 varied strongly with AMF availability in a plant species-specific manner,
 and caterpillar growth was unaffected by AMF. Inoculation with AMF
 increased foliar cardenolide concentrations consistently among milkweed
 species, but altered aboveground biomasses and foliar phosphorous
 concentrations in a plant species-specific fashion. Increased herbivore
 sequestration of cardenolides followed AMF-mediated increases in foliar
 cardenolide concentrations. Aphid performance declined with increasing
 foliar cardenolide concentrations, while caterpillar survival increased
 with aboveground biomass. Our findings suggest that by altering plant
 phenotype, the availability of AMF in soil has the potential to influence
 both top-down (via sequestration) and bottom up (via plant defense and
 nutrition) forces that operate on herbivores.
description: Mycorrhizae alter
 herbivore sequestration and performanceThe file
 Data-HerbivoreSeqandPerformance.zip holds three compressed data files,
 which contain the raw data used in our publication "Mycorrhizae alter
 toxin sequestration and performance of two specialist herbivores".
 "Aphids.xlsx" contains all aphid sequestration and performance
 data. "Caterpillars.xlsx" contains all caterpillar sequestration
 and performance data. "Controlplants.xlsx" contains all control
 plant data. Missing values are denoted with a period (.). Please see the
 README file for more detail about the individual data
 files.Data-HerbivoreSeqandPerformance.zip