Volume 177, June 2013, Pages 78–81

Short communication

The effects of aluminum and nickel in nectar on the foraging behavior of bumblebees

  • University of Pittsburgh, Department of Biological Sciences, Pittsburgh, PA 15260, USA
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1. Introduction

2. Methods

3. Results and discussion

Acknowledgments

References


Abstract

Metals in soil are known to negatively affect the health of many groups of organisms, but it is unclear whether they can affect plant-pollinator interactions, and whether pollinators that visit plants growing on contaminated soils are at risk of ingesting potentially toxic resources. We address whether the presence of metals in nectar alters foraging behavior by bumblebees by manipulating nectar with one of two common soil contaminants (Al or Ni) in flowers of Impatiens capensis (Balsaminaceae). While the presence of Al in nectar did not influence foraging patterns by bumblebees, flowers containing Ni nectar solutions were visited for shorter time periods relative to controls, and discouraged bees from visiting nearby Ni-contaminated flowers. However, because bumblebees still visited these flowers, they likely ingested a potentially toxic resource. Our findings suggest that soil metals could cascade to negatively affect pollinators in metal contaminated environments.


Highlights

► We address whether metals in nectar alter foraging behavior by bumblebees. ► Al in nectar did not influence foraging patterns by bumblebees. ► Ni nectar solutions were visited for shorter time periods relative to controls. ► Ni nectar solutions discouraged bees from visiting nearby Ni-contaminated flowers. ► Our findings suggest soil metals could cascade to negatively affect pollinators.

Keywords

  • Metals;
  • Nectar chemistry;
  • Pollinator behavior

Figures and tables from this article:

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Fig. 1. Example of experimental array. Arrays consisted of four field-collected flowers placed in water-filled centrifuge tubes. Two metal-treated flowers were placed 4 cm apart, and 20 cm apart from a pair of control flowers. Following an observed visitation sequence, all flowers in an array were replaced with unvisited flowers, and the location of metal-treated and control flowers were switched.

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Fig. 2. Mean foraging time (±SE) by bumblebees to treatment flowers. Asterisks indicate significant differences between treatments (P < 0.05).

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Fig. 3. The proportion of bumblebees that either visited the next closest flower (of the same treatment; white section), one of the two flowers in the other treatment in the array (gray section), or left the array entirely (black section). Data presented for both (A) Ni arrays and (B) Al arrays.

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Corresponding author.