DOI: 10.5061/dryad.fh078
title: Data from: Sensitivity of commercial pumpkin yield to potential decline among different groups of pollinating bees

description: The yield of animal-pollinated crops is threatened by bee declines, but
 its precise sensitivity is poorly known. We therefore determined the yield
 dependence of Hokkaido pumpkin in Germany on insect pollination by
 quantifying: (i) the relationship between pollen receipt and fruit set and
 (ii) the cumulative pollen deposition of each pollinator group. We found
 that approximately 2500 pollen grains per flower were needed to maximize
 fruit set. At the measured rates of flower visitation, we estimated that
 bumblebees (21 visits/flower lifetime, 864 grains/visit) or honeybees (123
 visits, 260 grains) could individually achieve maximum crop yield, whereas
 halictid bees are ineffective (11 visits, 16 grains). The pollinator fauna
 was capable of delivering 20 times the necessary amount of pollen. We
 therefore estimate that pumpkin yield was not pollination-limited in our
 study region and that it is currently fairly resilient to single declines
 of honeybees or wild bumblebees.
description: Single visit deposition
 of pumpkin pollen of three bee species groups in 2015Original source: single
 visit deposition (SVD) experiments in the field, pollen extracted by
 acetolysis; Open Office org Calc was used to create the file;
 abbrevations: "species" = bee species group ("bumble"
 = Bombus terrestris, B. lucorum; "halictid" = several
 Halictidae, mainly Lasioglossum malachurum; "honey" = Apis
 mellifera), "IT.span" = intertegular span.SVD.bee-species_pumpkin_2015.csvR script for the analysis of the single visit deposition dataData analysed "SVD.bee-species_pumpkin_2015.csv"; software R 3.2.2 (2015) usedR_script_SVD.RPollen grains at bagged and open anthers in 2012 and 2015Data collected in the field; Open Office org Calc used to create the data file.pollen.anther.csvR script analysing pollen at the anther dataData file used for the analysis "pollen.anther.csv", software R 3.2.2 (2015) used to create the file.R_script_pollen.anther.RVisitation rates of bee groups in videos in 2014Visitation rates collected by in total 54 hours of video recording in 18 fields in 2014. Open Office Org Calc was used to create this data file. "no.visits" = number of visits by the corresponding species groups, "species" = species group {"bumble" = Bombus terrestris, B. lucorum, B. lapidarium; "halictid" = several Halictidae, mainly Lasioglossum species; "honey" = Apis mellifera}, "start.time" = starting time of the video at three different time periods (7:00 am, 8:30 am, 10:00 am).vis.rate_video2014.csvHandling time of bee individuals (video data) in 2014Handling time of the 2100 bee individuals are derived from the videos recorded in 18 fields in 2014. Open Office org Calc was used to create the data file. Abbreviations: "species" = three different bee species groups ("bumble" = Bombus terrestris, B. lucorum, B. lapidarius; "halictid" = several Halictidae species, mainly Lasioglossum species; "honey" = Apis mellifera), "handling.time.s" = total time bees spent handling the flower in seconds, "nectar.time.s" = total time bees spent on/at the stigma and feeding nectar, "group.halictid" = halictid species were divided into two size classes (length ~ 6 mm or ~ 8 mm), "successful.visit" = visit, where stigma was touched = nectar.time.s &gt; 0; "start.time" = starting time of the video divided into three time periods (7:00 am, 8:30 am, 10:00 am).handling.time_video2014.csvR script analysing video dataData files analysed "vis.rate_video2014.csv" and "handling.time_video2014". Software R 3.2.2 (2015) was used.R_script_video.data_lmer.RPollen-yield experiment data from 2014 and 2015Data from hand-pollination experiments in fields with different levels of pollen deposition in 2014 (5 levels) and in 2015 (7 levels). Details see manuscript and Table S1 in the supplementary material. Open Office Calc used to create this file. Abbreviations: "harvestable" = 1, if pumpkin fruits could be harvested, "marketable" = 1, if pumpkin fruits weigh more than 800 g.pollen.yield.2014_2015.red.csvR script analysing the hand-pollination dataData files used "mean_hpa.csv" and "pollen.yield.2014_2015.red". Software R 3.2.2 (2015) used for analysis.R_script_yield.RCalculated pollen deposition per bee species groupFormulas used for the calculation from "R_script_SVD". Data used in the formulas from field data "handling.time_video2014.csv", "vis.rate_video2014.csv", "SVD.bee-species_pumpkin_2015.csv", one sheet per bee species group (d.bumble, d.honey, d.halictid). Microsoft Excel used to create the file.calculated deposition.model.xlsR script modelling the contribution of bee groups to pumpkin yieldSingle visit pollen deposition data is the calculated data from the file "calculated deposition.model.xls". Data file used "mean_hpa.csv". Software R 3.2.2 used.R_script_model.RMean values of fruit set per pollen deposition levelMean values of set of harvestable pumpkins per pollen deposition level derived from data file "pollen.yield.2014_2015.red.csv". Open Office Calc used to create the file. Abbrevations: "pollen.est" = estimated level of pollen deposition, "mean" = mean value of set of harvestable pumpkins, "mp2" = mean value + E-13 in percent.mean_hpa.csv