Analyzing the Dietary Diary of Bumble Bee

Abstract

Bumble bees are important crop pollinators and provide important pollination services to their respective ecosystems. Their pollen diet and thus food preferences can be characterized through nucleic acid sequence analysis. We present ITS2 amplicon sequence data from pollen collected by bumble bees. The pollen was collected from six different bumble bee colonies that were placed in independent agricultural landscapes. We compared next-generation (Illumina), i.e., short-read, and thirdgeneration (Nanopore), i.e., MinION, sequencing techniques. MinION data were preprocessed using traditional and Nanopore specific tools for comparative analysis and were evaluated in comparison to short-read sequence data with conventional processing. Based on the results, the dietary diary of bumble bee in the studied landscapes can be identified. It is known that short reads generated by next-generation sequencers have the advantage of higher quality scores while Nanopore yields longer read lengths. We show that assignments to taxonomic units yield comparable results when querying against an ITS2-specific sequence database. Thus, lower sequence quality is compensated by longer read lengths. However, the Nanopore technology is improving in terms of data quality, much cheaper, and suitable for portable applications. With respect to the studied agricultural landscapes we found that bumble bees require higher plant diversity than only crops to fulfill their foraging requirements.

Using ITS2 metabarcoding and microscopy to analyse shifts in pollen diets of honey bees and bumble bees along a mass‐flowering crop gradient

“…Our results can contribute to ongoing discussions that apply and test different methods to quantify pollen grain counts (Baksay et al., 2020; Pornon et al., 2016). Given the growing interest in both microscopic (Gallardo‐Caballero et al., 2019) and molecular (Baksay et al., 2020; Leidenfrost et al., 2020) pollen analyses for pollen identification and quantification, our study highlights that the methods should be chosen carefully and in a targeted manner.…”

“…New developments in microscopic pollen detection using deep learning techniques (Gallardo‐Caballero et al., 2019) or in full‐length amplicon or genome sequencing with, for example, nanopore sequencing techniques (Lang et al . 2019; Leidenfrost et al., 2020; Peel et al., 2019) could improve the weaknesses of both approaches (e.g., time expenditure in microscopy or quantification accuracy in molecular methods). However, studies are needed to compare and evaluate the accuracy of those new developments.…”

“…Bees collect pollen because it provides proteins, vitamins and minerals for larval development (Thorp, 2000). Bees often forage on a large number of different plant species to meet their dietary requirements (Alaux et al., 2017; Di Pasquale et al., 2013; Leidenfrost et al., 2020) and they can balance nutrient deficits by collecting either greater amounts or diversity of pollen (Danner et al., 2017; Hendriksma & Shafir, 2016). Colony development can be enhanced through increasing intake of higher amounts and/or better pollen quality in terms of pollen diversity or species composition (Brodschneider & Crailsheim, 2010; Kämper et al., 2016; Vaudo et al., 2018).…”

Crop pollination services: Complementary resource use by social vs solitary bees facing crops with contrasting flower supply

“…Similar spillover processes have been observed from mango (Simba et al., 2018) or OSR (Kovacs‐Hostyanszki et al., 2013) to natural vegetation. Both crops, OSR and strawberry, can provide pollen and nectar as a reward (Bänsch, Tscharntke, Ratnieks, et al., 2020; Knopper et al., 2016; Leidenfrost et al., 2020). It has been shown that the attractiveness of OSR to honey bees and some solitary bee species is higher than the attractiveness of strawberry while the attractiveness of both crops to bumble bees is similar (Knopper et al., 2016).…”

“…Similar spillover processes have been observed from mango (Simba et al, 2018) or OSR (Kovacs-Hostyanszki et al, 2013) to natural vegetation. Both crops, OSR and strawberry, can provide pollen and nectar as a reward (Bänsch, Tscharntke, Ratnieks, et al, 2020;Knopper et al, 2016;Leidenfrost et al, 2020).…”