DOI: 10.5061/dryad.wpzgmsbvj
title: Local habitat complexity and its effects on herbivores and predators in urban agroecosystems

description: In urban community gardens, cultivated vegetation provides variable levels
 of habitat complexity, which can suppress pests by promoting predator
 diversity and improving pest control. In this study, we examine three
 components of the structural complexity of garden vegetation (cover,
 diversity, and connectivity) to investigate whether higher garden
 vegetation complexity leads to fewer herbivores, more predators, and
 higher predation. We worked in eight community gardens where we quantified
 vegetation complexity, sampled the arthropod community, and measured
 predation on cornworm eggs. We found that plots with high vegetation cover
 supported higher species richness and greater abundance of predatory
 insects. High vegetation cover also supported a greater abundance and
 richness of spiders. In contrast, high vegetation diversity was negatively
 associated with predator abundance. While high predator abundance was
 positively associated with egg predation, greater predator species
 richness had a negative impact on egg predation, suggesting that
 antagonism between predators may limit biological control. Community
 gardeners may thus manipulate vegetation cover and diversity to promote
 higher predator abundance and diversity in their plots. However, the
 species composition of predators and the prevalence of interspecific
 antagonism may ultimately determine subsequent impacts on biological pest
 control.
description: These datasets describe arthropods, predation levels, and
 vegetation characteristics sampled and measured in urban community garden
 sites in the California central coast in August 2019. Arthropods were
 sampled using a combination of visual surveys of garden plants and pitfall
 traps placed in sample plots. Predation levels were measured using corn
 earworm moth eggs as sentinel prey in sentinel pest experiments at each
 sample plot. Vegetation characteristics were measured in four 1.5 x 1.5 m
 sample plots per garden site. We used generalized linear models to analyze
 relationships between arhtropod abundance/richness, predation levels, and
 vegetation characteristics. More detailed methods are described in our
 <em>Insects</em> publication of this study. Details about each
 dataset are found in the README file.
 <strong>Datasets included: </strong>
 1) PitfallTrap_1.5.24 Abundance
 and species richness of herbivores and predators (all predators, ants, and
 spiders) sampled through pitfall traps Egg predation
 (LRR, effect size) measured through sentinel pest experiments
 Vegetation cover, diversity, and connectivity measurements for
 each sample plot 2)
 VisualSurvey_1.5.24 Abundance and species
 richness of herbivores (all herbivores, aphids, and whiteflies) and
 predators (all predators, ants, and spiders) sampled through visual
 surveys of plants Egg predation (LRR, effect size)
 measured through sentinel pest experiments Vegetation
 cover, diversity, and connectivity measurements and gardener bed size for
 each sample plot Missing value are
 inducated by NA. See README file for additional details. 
description: # Herbivores and predators Access this dataset on Dryad:
 These datasets are the
 summary data from the paper, "Local Habitat Complexity and Its
 Effects on Herbivores and Predators in Urban Agroecosystems," by
 Azucena Lucatero, Shalene Jha, and Stacy Philpott published in *Insects*
 in 2024. They describe herbivore and predator biodiversity, predation on
 corn earworm moth eggs, and vegetation characteristics (cover, diversity,
 and connectivity) of plots in urban community garden sites in the
 California central coast sampled in August 2019. ## Description of the
 data and file structure We include the two datasets that were analyzed in
 this study: **1) PitfallTrap_1.5.24.csv** This dataset includes the
 abundance and species richness of arthropods sampled through pitfall
 traps, egg predation measured through sentinel pest experiments, and
 sample plot characteristics. Column Heads: * Site * VegTreat (vegetation
 complexity treatment; highveg = high vegetation complexity, lowveg = low
 vegetation complexity) * SamplingRound (1 indicating sampling on August
 1st, 2019; 2 indicating sampling on August 3rd, 2019) Response Variables:
 * TotalHerbAbundance (abundance of all sampled herbivores) *
 TotalHerbRichness (species richness of all sampled herbivores) *
 TotalNEAbundance (abundance of all sampled predators; NE = natural
 enemies) * TotalNERichness (species richness of all sampled predators; NE
 = natural enemies) * AntAbundance (abundance of all sampled ants) *
 AntSpeciesRichness (species richness of all sampled ants) *
 SpiderAbundance (abundance of all sampled spiders) * SpiderSpeciesRichness
 (species richness of all sampled spiders) * EggLRR (effect size of
 predation on corn earworm moth eggs in sentinel pest experiments;
 calculated as the log response ratio (LRR = LN(proportion eggs removed in
 open treatments)—LN(proportion eggs removed in bagged treatments))
 Predictor Variables * VegDensity (vegetation cover, measured as the
 percent cover of plants in 1.5 x 1.5 m sample plot) * VegDiversity
 (vegetation diversity, measured as the number of plant species in 1.5 x
 1.5 m sample plot) * VegConnectivity (vegetation connectivity, measured as
 the 1/the longest distance between two plants in 1.5 x 1.5 m sample plot)
 **2) VisualSurvey_1.5.24.csv** This dataset includes the abundance and
 species richness of arthropods sampled through visual surveys of plants,
 egg predation measured through sentinel pest experiments, and sample plot
 characteristics. Column Heads: * Site * VegTreat (vegetation complexity
 treatment; highveg = high vegetation complexity, lowveg = low vegetation
 complexity) * SamplingRound (1 indicating sampling on August 1st, 2019; 2
 indicating sampling on August 3rd, 2019) Response Variables: *
 HerbAbundance (abundance of all sampled herbivores) * HerbRichness
 (species richness of all sampled herbivores) * AphidAbundance (abundance
 of all sampled aphids) * AphidRichness (species richness of all sampled
 aphids) * WhiteflyAbundance (abundance of all sampled whiteflies) *
 NEAbundance (abundance of all sampled predators; NE = natural enemies) *
 NERichness (species richness of all sampled predators; NE = natural
 enemies) * SpiderAbundance (abundance of all sampled spiders) *
 SpiderRichness (species richness of all sampled spiders) * AntAbundance
 (abundance of all sampled ants) * AntRichness (species richness of all
 sampled ants) * EggLRR (effect size of predation on corn earworm moth eggs
 in sentinel pest experiments; calculated as the log response ratio (LRR =
 LN(proportion eggs removed in open treatments)—LN(proportion eggs removed
 in bagged treatments)) Predictor Variables: * VegDensity (vegetation
 cover, measured as the percent cover of plants in 1.5 x 1.5 m sample plot)
 * VegDiversity (vegetation diversity, measured as the number of plant
 species in 1.5 x 1.5 m sample plot) * VegConnectivity (vegetation
 connectivity, measured as the 1/the longest distance between two plants in
 1.5 x 1.5 m sample plot) * BedSize (length x width of the entire garden
 bed; 1.5 x 1.5 m plots are each within a gardener bed) ## Sharing/Access
 information This dataset was analyzed in the following published article:
 Lucatero, A., Jha, S., & Philpott, S. M. (2024). Local Habitat
 Complexity and Its Effects on Herbivores and Predators in Urban
 Agroecosystems. *Insects*, 15(1), 41.