DOI: 10.5061/dryad.4g9g0
title: Data from: Simplifying understory complexity in oil palm plantations is associated with a reduction in the density of a cleptoparasitic spider, Argyrodes miniaceus (Araneae: Theridiidae), in host (Araneae: Nephilinae) webs

description: Expansion of oil palm agriculture is currently one of the main drivers of
 habitat modification in Southeast Asia. Habitat modification can have
 significant effects on biodiversity, ecosystem function, and interactions
 between species by altering species abundances or the available resources
 in an ecosystem. Increasing complexity within modified habitats has the
 potential to maintain biodiversity and preserve species interactions. We
 investigated trophic interactions between Argyrodes miniaceus, a
 cleptoparasitic spider, and its Nephila spp. spider hosts in mature oil
 palm plantations in Sumatra, Indonesia. A. miniaceus co-occupy the webs of
 Nephila spp. females and survive by stealing prey items caught in the web.
 We examined the effects of experimentally manipulated understory
 vegetation complexity on the density and abundance of A. miniaceus in
 Nephila spp. webs. Experimental understory treatments included enhanced
 complexity, standard complexity, and reduced complexity understory
 vegetation, which had been established as part of the ongoing Biodiversity
 and Ecosystem Function in Tropical Agriculture (BEFTA) Project. A.
 miniaceus density ranged from 14.4 to 31.4 spiders per square meter of
 web, with significantly lower densities found in reduced vegetation
 complexity treatments compared with both enhanced and standard treatment
 plots. A. miniaceus abundance per plot was also significantly lower in
 reduced complexity than in standard and enhanced complexity plots.
 Synthesis and applications: Maintenance of understory vegetation
 complexity contributes to the preservation of spider host–cleptoparasite
 relationships in oil palm plantations. Understory structural complexity in
 these simplified agroecosystems therefore helps to support abundant spider
 populations, a functionally important taxon in agricultural landscapes. In
 addition, management for more structurally complex agricultural habitats
 can support more complex trophic interactions in tropical agroecosystems.
description: Cleptoparasite density
 dataData used for the
 analyses described in publication titled "Simplifying understory
 complexity in oil palm plantations is associated with a reduction in the
 density of a cleptoparasitic spider, Argyrodes miniaceus (Araneae:
 Theridiidae), in host (Araneae: Nephilinae) webs". Data includes
 information about each individual host (Nephila spp.) web as follows:
 "Plot" = assigned plot code for each treatment plot;
 "Treatment" = understory complexity treatment, including
 "E" (enhanced complexity), "N" (standard complexity),
 and "R" (reduced complexity); "Date" = date of survey;
 "Time" = time of survey; "Weather" = weather during
 survey; "Spider Height" = height of host (Nephila spp.) spider
 from the ground; "Spider size" = length of host (Nephila spp.)
 spider; "Web L" = host web length; "Web W" = host web
 width; "# cleptos" = the number of Argyrodes miniaceus
 cleptoparasites present in the host web; and "# males" = the
 number of males present in the host web.