DOI: 10.5061/dryad.kg4bc56
title: Even obligate symbioses show signs of ecological contingency: impacts of symbiosis for an invasive stinkbug are mediated by host plant context

description: Many species interactions are dependent on environmental context, yet the
 benefits of obligate, mutualistic microbial symbioses to their hosts are
 typically assumed to be universal across environments. We directly tested
 this assumption, focusing on the symbiosis between the sap-feeding insect
 Megacopta cribraria and its primary bacterial symbiont Candidatus
 Ishikawaella capsulata. We assessed host development time, survival, and
 body size in the presence and absence of the symbiont on two alternative
 host plants, and in the insects' new invasive range. We found that
 association with the symbiont was critical for host survival to adulthood
 when reared on either host plant, with few individuals surviving in the
 absence of symbiosis. Developmental differences between hosts with and
 without microbial symbionts, however, were mediated by the host plants on
 which the insects were reared. Our results support the hypothesis that
 benefits associated with this host-microbe interaction are environmentally
 contingent, though given that few individuals survive to adulthood without
 their symbionts, this may have minimal impact on ecological dynamics and
 current evolutionary trajectories of these partners.
description: Read Me
 FileRead me file containing
 information about all data and code.Field Data
 AnalysisCode used to
 statistically analyze field experimental data on development time,
 survival, and body measurements and to make figures.FieldDataAnalysis.pdfFIeld_DevelopmentTime_TreatmentMeansThe calculated average development times (in weeks) to develop to each life stage on each plant type. Sym is the treatment of normal (pos) and disrupted (neg) symbiosis. Plant is the species of host plant, kudzu or soybean. Life stages are listed at 1 through 5 and stage 6 represents the adult stage.Field_DevelopmentTimeWe counted the number of bugs at each life stage on each plant and recorded weekly. ym is the treatment of normal (pos) and disrupted (neg) symbiosis. Plant is the species of host plant, kudzu or soybean. Life stages are listed at 1 through 5 and stage 6 represents the adult stage.Field_survivalThe calculated weekly mortality of bugs based on initial numbers placed on each plant and developmental counts each week.BodyMeasurement_scutellum_normalsymbiosis_treatmentsBody measurements of scutellum width in millimeters of field collected adults from the normal symbiosis treatments on either kudzu or soybean.BodyMeasurement_scutellum_soy_treatmentsBody measurements of scutellum width in millimeters of field collected adults from soybean treatments either normal (pos) or disrupted (neg) symbiosis.BodyMeasurement_weight_normalsymbiosis_treatmentsBody measurements of weight in grams of field collected adults from the normal symbiosis treatments on either kudzu or soybean.BodyMeasurement_weight_soy_treatmentsBody measurements of weight in grams of field collected adults from soybean treatments either normal (pos) or disrupted (neg) symbiosis.Lab Data AnalysisCode used to statistically analyze development time and survival of lab experimental data and to make figures.LabDataAnalysis.pdfLab_behaviorCode of the recorded location of early instar stages on plants in the laboratory experiment.Lab_survivalDaily survival (alive or dead) of each life stage on each plant. Life stages of early instars are indicated by the numbers 1 through 3.Lab_developmentDaily counts of bugs for each life stage on each plant type and for normal (pos) and disrupted (neg) symbiosis.