DOI: 10.5061/dryad.x95x69pwm
title: Data from: Salicylate plant defenses reduce aphid nutritional quality and increase predator consumption

description: Plant-induced defenses can shape multitrophic interactions by affecting
 herbivore performance and altering their suitability as prey. While the
 direct effects of these defenses on herbivores are well documented, their
 indirect consequences— particularly for predator behavior and biological
 control effectiveness— remain less understood. In our study, we examined
 how activating salicylic acid (SA)-mediated defenses in tomato plants
 affects the performance and nutritional quality of the
 aphid, Macrosiphum euphorbiae, and how this intraspecific
 variation in aphid quality as prey impacts the predation by the lady
 beetle predator, Hippodamia convergens. Aphids on SA-treated plants
 exhibited reduced body mass, protein, and lipid content, indicating lower
 nutritional value as prey. Correspondingly, we recorded a stronger decline
 in aphid population on SA-treated plants in the presence of predators. To
 investigate the effects of reduced aphid quality on predation, we
 conducted a controlled no-choice assay, which showed that individual lady
 beetle predators consume more aphids from the SA-treated plants. This
 increased consumption is consistent with compensatory feeding in response
 to nutrient-poor prey, although alternative explanations, such as
 increased prey vulnerability, should also be considered. Our findings
 demonstrate that SA-mediated defenses can shape predator-prey interactions
 through bottom-up effects on prey quality and underscore the need to
 consider these cascading effects when evaluating the ecological impact of
 plant resistance traits in biological control strategies.
description: # Salicylate plant defenses reduce aphid nutritional quality and increase
 predator consumption **Journal**: Ecological Entomology (Accepted)
 **Manuscript ID**: 25-0018-EEN **Authors** * M.S. Bijay Subedi * Dr.
 Victoria Marie Pocius * Ms. Mary Arlin Bunnell * Ms. Abigail Myers * Dr.
 Mônica F. Kersch-Becker **Contact Information** * M.S. Bijay Subedi:
 [beejjus@gmail.com](mailto:beejjus@gmail.com) * Dr. Mônica F.
 Kersch-Becker: [mfkb@psu.edu](mailto:mfkb@psu.edu) #### **Dataset
 Description** This dataset investigates how SA-mediated plant defenses
 affect herbivore (aphid) quality and predator (lady beetle) consumption
 rates. It combines measures of aphid life history traits, body
 macronutrient profiles, and predator feeding behavior under greenhouse and
 laboratory conditions. **File Information** **Main File:**
 `Plant_defense_Prey_quality_Predation_metasheet.xlsx` (Microsoft Excel
 Workbook) #### Sheet Descriptions ### `Method.2.3_aphid_reproduction`
 Purpose: Records the reproductive output and survival of individual aphids
 across control and SA-treated plants. Measurement: Daily counts of adults
 and nymphs, cumulative total nymph production, and per-capita nymph
 production per adult. Context: Captures how SA-mediated plant defenses
 affect aphid reproduction during their lifespan (~30 days) under caged
 conditions. ### `Method.2.3_lifespan` Purpose: Records aphid survivorship
 across plant treatments. Measurement: Time to death (days) for F2
 generation nymphs following initial infestation, censored if alive at end.
 Context: Allows survival curve analysis comparing aphid lifespan on
 SA-treated versus control plants. ### `Method.2.4_biomass` Purpose:
 Individual aphid body mass measurements. Measurement: Dry weight (mg) of
 aphids after nine days of feeding. Context: Tests if SA-mediated defenses
 reduce aphid growth and final body size. ### `Method.2.4_glucose_analysis`
 Purpose: Aphid glucose content normalized to body mass. Measurement:
 Colorimetric glucose assay readings per mg aphid biomass. Context:
 Evaluates whether SA treatments alter aphid carbohydrate reserves. ###
 `Method.2.4_triglyceride_analysis` Purpose: Aphid triglyceride (lipid)
 content normalized to body mass. Measurement: Triglyceride levels from
 lipid extraction assays per mg aphid biomass. Context: Determines the
 effects of plant defense on aphid lipid storage important for energy and
 reproduction. ### `Method.2.4_protein_analysis` Purpose: Aphid protein
 content normalized to body mass. Measurement: Bradford assay-derived
 protein concentrations per mg aphid. Context: Assesses the nutritional
 quality of aphids in terms of protein, a key macronutrient for predators.
 ### `Method.2.5a_cage_predation` Purpose: Results from in-cage predation
 assays under semi-natural conditions. Measurement: Aphid initial and final
 counts under predator-present and predator-absent treatments; predator
 numbers introduced per cage. Context: Tests combined effects of plant
 defense and natural predation on aphid suppression. ###
 `Method.2.5b_petridish_predation` Purpose: Results from Petri-dish
 no-choice predator feeding assays. Measurement: Number of aphids consumed
 and biomass consumed by individual lady beetles over 4 hours. Context:
 Measures compensatory feeding behavior of predators when aphid prey varies
 in quality due to plant treatment. ### `metadata` Purpose: Explains
 variable names and units for all other sheets. Context: Ensures clarity
 and reuse of the dataset. ### Excel Sheets:
 **`Method.2.3_aphid_reproduction`** * **Description**: Records daily aphid
 reproduction and adult survival under control and SA-treated plants. *
 **Variables**: * `Plant` — Unique plant ID * `Treatment` — SA-treated or
 Control * `Trial` — Experimental block * `total_nymphs` — Cumulative nymph
 production * `total_adults` — Total surviving adults * `nymph_per_adult` —
 Nymph production per surviving adult **`Method.2.3_lifespan`** *
 **Description**: Aphid survival time across treatments. * **Variables**: *
 `time` — Time in days * `p_id` — Aphid individual ID * `replicate` —
 Replicate ID * `treatment` — SA-treated or Control * `trial` —
 Experimental block * `censor` — Censoring status (0 = dead, 1 = alive) *
 `status` — Survival status **`Method.2.4_biomass`** * **Description**:
 Individual aphid body mass measurements. * **Variables**: * `plant` —
 Plant ID * `treatment` — SA-treated or Control * `weight_mg` — Individual
 mass in milligrams * `trial` — Trial replicate * `apihd` — Aphid sample ID
 **`Method.2.4_glucose_analysis`** * **Description**: Aphid glucose
 concentration normalized by body weight. * **Variables**: * `sample` —
 Sample ID * `treatment` — SA-treated or Control *
 `glucose_concentration_mean` — Mean glucose reading (µg/mg) * `weight_mg`
 — Sample weight * `glucose_per_mg_aphid` — Glucose normalized per mg aphid
 **`Method.2.4_triglyceride_analysis`** * **Description**: Aphid
 triglyceride (lipid) concentration per mg body weight. * **Variables**: *
 `sample` — Sample ID * `treatment` — SA-treated or Control *
 `triglyceride_concentration_mean` — Mean triglyceride reading (µg/mg) *
 `weight_mg` — Sample weight * `triglyceride_mg_aphid` — Triglyceride
 normalized per mg aphid **`Method.2.4_protein_analysis`** *
 **Description**: Aphid protein concentration per mg body weight. *
 **Variables**: * `sample` — Sample ID * `treatment` — SA-treated or
 Control * `weight_mg` — Sample weight * `protein_concentration_fr_gluc` —
 Raw protein concentration * `protein_by_weight_mean` — Protein per mg
 aphid **`Method.2.5a_cage_predation`** * **Description**: In-cage aphid
 population suppression under predator-present and predator-absent
 conditions. * **Variables**: * `cage_id` — Unique cage ID * `trial` —
 Experiment block * `defense_code` — Numerical defense treatment code *
 `defense` — SA-treated or Control * `predator` — Predator present (Yes/No)
 * `block` — Block number * `total_i` — Initial aphid count *
 `pred_added_n` — Number of predators added * `total_f` — Final aphid count
 **`Method.2.5b_petridish_predation`** * **Description**: Petri-dish
 predator feeding assays measuring aphid mortality and biomass consumption.
 * **Variables**: * `trial` — Trial replicate * `defense` — SA-treated or
 Control * `time_min` — Time (minutes) * `petridish_id` — Unique Petri dish
 ID * `inoculation_n` — Initial number of aphids * `weight_mg` — Initial
 biomass * `n_consumed` — Number of aphids consumed * `weight_mg_consumed`
 — Biomass consumed **`metadata`** * **Description**: Descriptions and
 explanations for all column headers used across sheets. File Formats *
 Excel Workbook (.xlsx) for tabular data * CSV format can be generated for
 preservation and compatibility if needed. Variable Notes * Biomass
 measures are reported in milligrams (mg). * Nutrient concentrations are
 normalized by body mass wherever indicated. Software Used * R version
 4.2.2 * Packages: `glmmTMB`, `emmeans`, `DHARMa`, `car`, `survival`
 Licensing All data are made available under the **Creative Commons CC0
 Public Domain Dedication**. No rights reserved.