DOI: 10.5061/dryad.73n5tb33d
title: Data from: Diverse pollen nutrition can improve the development of solitary bees but does not mitigate negative pesticide impacts

description: Floral resource loss and pesticide exposure are major threats to bees in
 intensively managed agroecosystems, but interactions among these drivers
 remain poorly understood. Altered composition and lowered diversity of
 pollen nutrition may reinforce negative pesticide impacts on bees. Here we
 investigated the development and survival of the solitary bee Osmia
 bicornis provisioned with three different pollen types, as well as a
 mixture of these types representing a higher pollen diversity. We exposed
 bees of each nutritional treatment to five pesticides at different
 concentrations in the laboratory. Two field-realistic concentrations of
 three nicotinic acetylcholine receptor (nAChR) modulating insecticides
 (thiacloprid, sulfoxaflor and flupyradifurone), as well as of two
 fungicides (azoxystrobin and tebuconazole) were examined. We further
 measured the expression of two detoxification genes (CYP9BU1, CYP9BU2)
 under exposure to thiacloprid across different nutrition treatments as a
 potential mechanistic pathway driving pesticide-nutrition interactions. We
 found that more diverse pollen nutrition reduced development time,
 enhanced pollen efficacy (cocoon weight divided by consumed pollen weight)
 and pollen consumption, and increased weight of O. bicornis after larval
 development (cocoon weight). Contrary to fungicides, high field-realistic
 concentrations of all three insecticides negatively affected O. bicornis
 by extending development times. Moreover, sulfoxaflor and flupyradifurone
 also reduced pollen efficacy and cocoon weight, and sulfoxaflor reduced
 pollen consumption and increased mortality. The expression of
 detoxification genes differed across pollen nutrition types, but was not
 enhanced after exposure to thiacloprid. Our findings highlight that
 lowered diversity of pollen nutrition and high field-realistic exposure to
 nAChR modulating insecticides negatively affected the development of O.
 bicornis, but we found no mitigation of negative pesticide impacts through
 increased pollen diversity. These results have important implications for
 risk assessment for bee pollinators, indicating that negative effects of
 nAChR modulating insecticides to developing solitary bees are currently
 underestimated.
description: # Data from: Diverse pollen nutrition can improve the development of
 solitary bees but does not mitigate negative pesticide impacts
 ## DATA & FILE
 OVERVIEW ### File List & Short Description: *
 **Development_data.csv**: Data collected for individual developing bees *
 **Gene_expression_data.csv** Data collected for analysis of gene
 expression levels of detoxification genes (CYP9BU1 and CYP9BU2) ##
 DATA-SPECIFIC INFORMATION ### Variable List **SPECIFIC DATASET -
 Development_data.csv** * **plate**: number of wooden plate on which the
 developing bee was located * **position**: position (A-I) on the wooden
 plate on which the developing bee was located * **pesticide**: pesticide
 to which the bee was exposed (or not exposed, if it was a control bee, see
 concentration.factor) * **concentration.factor**: pesticide concentration
 to which the bee was exposed (low: low concentration, high: high
 concentration, c: water-only-control, ac: water-acetone-control) *
 **concentration.ppb**: concentration of the pesticide used (in ppb, µg/kg)
 * **nutrition**: pollen nutrition type offered to the developing bee (as
 pollen provision) * **egg.collection**: date of egg collection (start of
 exposure to pesticide/control) * **larva**: date on which the developing
 bee reached the larval stage * **feeding.larva**: date on which the
 developing bee started feeding on the pollen provision *
 **feeding.defecating.larva**: date on which the bee larva started to
 defecate * **spinning.larva**: date on which the bee larva initiated
 cocoon spinning (used to calculate development time) * **pale.cocoon**:
 date on which the bee larva finished cocoon spinning, cocoon still pale *
 **dark.cocoon**: date on which the finished cocoon appeared dark *
 **death.larva**: date on which the bee larva was observed dead (in case it
 died) * **incubation.emergence**: date on which the cocoon was incubated
 at room temperature after wintering in order for the adult bee to emerge *
 **date.emergence**: date on which adult bee emerged from cocoon (and was
 released outdoors) * **emergence.status**: indicates whether bee emerged
 from cocoon as adult or not * **sex**: sex of bee (either determined after
 emergence or - in case bee did not emerge - after opening the cocoon) *
 **development.time.days**: number of days needed from hatching from the
 egg until cocoon spinning * **pollen.consumed.mg**: amount of pollen
 consumed by bee larva (400 mg were provided) * **pollen.fully.consumed**:
 binary variable indicating whether the total amount of pollen (400 mg) was
 consumed (1) or not (0) * **pollen.efficacy**: cocoon weight/pollen
 consumed (mg/mg) * **cocoon.weight.mg**: weight of cocoon before wintering
 (after completed metamorphosis, mg) * **survival**: indicates whether a
 bee survived and successfully emerged as adult or not * **comment**: any
 additional comments for a sample * **NOTE on cells containing NA**: In
 case a developing bee died, NAs were inserted in the data table for the
 developmental stages that were not observed for this individual and for
 the measurements that could not be taken. For surviving bees,
 "death.larva" was set to NA. Additionally, in several cases,
 specific developmental stages could not be observed for some developing
 bees, e.g., in case a larva was already in the "feeding.larva"
 stage when it was first observed as larva. **SPECIFIC DATASET -
 Gene_expression_data.csv** * **sample.id**: ID of developing bee (sample)
 * **pesticide**: pesticide to which the bee was exposed (or not exposed,
 if it was a control bee, see concentration.factor) NOTE: only thiacloprid
 was used in the gene expression experiment * **concentration.factor**:
 pesticide concentration, to which the bee was exposed (high: high
 concentration (0.75 mg/kg thiacloprid), ac: water-acetone-control) *
 **nutrition**: pollen nutrition type offered to the developing bee (as
 pollen provision) * **gene**: gene of which expression level was measured
 (CYP9BU1 or CYP9BU2) * **fold.change**: gene expression level measured as
 2^-ΔΔct, reference level is mix nutrition water-acetone-control