Limits...
Can winter-active bumblebees survive the cold? Assessing the cold tolerance of Bombus terrestris audax and the effects of pollen feeding.

Owen EL, Bale JS, Hayward SA - PLoS ONE (2013)

Bottom Line: The first evidence of RCH in any Hymenoptera is shown.In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature.These results are discussed in the light of winter active bumblebees and climate change.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.

ABSTRACT
There is now considerable evidence that climate change is disrupting the phenology of key pollinator species. The recently reported UK winter activity of the bumblebee Bombus terrestris brings a novel set of thermal challenges to bumblebee workers that would typically only be exposed to summer conditions. Here we assess the ability of workers to survive acute and chronic cold stress (via lower lethal temperatures and lower lethal times at 0°C), the capacity for rapid cold hardening (RCH) and the influence of diet (pollen versus nectar consumption) on supercooling points (SCP). Comparisons are made with chronic cold stress indices and SCPs in queen bumblebees. Results showed worker bees were able to survive acute temperatures likely to be experienced in a mild winter, with queens significantly more tolerant to chronic cold temperature stress. The first evidence of RCH in any Hymenoptera is shown. In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature. These results are discussed in the light of winter active bumblebees and climate change.

Show MeSH

Related in: MedlinePlus

Determination of a discriminating treatment for rapid cold hardening in worker bumblebees (Bombus terrestris audax).Mean survival (±SE) of worker bumblebees exposed to periods of 2, 4, 8 and 10 h at −5 and −6°C, n = 30 per temperature.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3818302&req=5

pone-0080061-g003: Determination of a discriminating treatment for rapid cold hardening in worker bumblebees (Bombus terrestris audax).Mean survival (±SE) of worker bumblebees exposed to periods of 2, 4, 8 and 10 h at −5 and −6°C, n = 30 per temperature.

Mentions: Mean survival of workers at −5°C decreased with increasing duration of cold exposure, from 80±16.3% after 2 h to 13.3±13.3% after 10 h exposure (Figure 3). An independent samples Kruskal Wallis test (p = 0.03, χ = 8.66) with pairwise comparisons indicated survival at 2 and 10 h were significantly different (p = 0.045 χ = 9.92). Mean survival of workers at −6°C was consistently low (between 3.3±3.3 and 16.7±13.1% survival) with no significant difference between durations at this temperature (p = 0.19, χ = 0.93). Based on the above data, 10 h at −5°C was chosen to be the discriminating treatment to determine a RCH response.


Can winter-active bumblebees survive the cold? Assessing the cold tolerance of Bombus terrestris audax and the effects of pollen feeding.

Owen EL, Bale JS, Hayward SA - PLoS ONE (2013)

Determination of a discriminating treatment for rapid cold hardening in worker bumblebees (Bombus terrestris audax).Mean survival (±SE) of worker bumblebees exposed to periods of 2, 4, 8 and 10 h at −5 and −6°C, n = 30 per temperature.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3818302&req=5

pone-0080061-g003: Determination of a discriminating treatment for rapid cold hardening in worker bumblebees (Bombus terrestris audax).Mean survival (±SE) of worker bumblebees exposed to periods of 2, 4, 8 and 10 h at −5 and −6°C, n = 30 per temperature.
Mentions: Mean survival of workers at −5°C decreased with increasing duration of cold exposure, from 80±16.3% after 2 h to 13.3±13.3% after 10 h exposure (Figure 3). An independent samples Kruskal Wallis test (p = 0.03, χ = 8.66) with pairwise comparisons indicated survival at 2 and 10 h were significantly different (p = 0.045 χ = 9.92). Mean survival of workers at −6°C was consistently low (between 3.3±3.3 and 16.7±13.1% survival) with no significant difference between durations at this temperature (p = 0.19, χ = 0.93). Based on the above data, 10 h at −5°C was chosen to be the discriminating treatment to determine a RCH response.

Bottom Line: The first evidence of RCH in any Hymenoptera is shown.In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature.These results are discussed in the light of winter active bumblebees and climate change.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences, University of Birmingham, Birmingham, United Kingdom.

ABSTRACT
There is now considerable evidence that climate change is disrupting the phenology of key pollinator species. The recently reported UK winter activity of the bumblebee Bombus terrestris brings a novel set of thermal challenges to bumblebee workers that would typically only be exposed to summer conditions. Here we assess the ability of workers to survive acute and chronic cold stress (via lower lethal temperatures and lower lethal times at 0°C), the capacity for rapid cold hardening (RCH) and the influence of diet (pollen versus nectar consumption) on supercooling points (SCP). Comparisons are made with chronic cold stress indices and SCPs in queen bumblebees. Results showed worker bees were able to survive acute temperatures likely to be experienced in a mild winter, with queens significantly more tolerant to chronic cold temperature stress. The first evidence of RCH in any Hymenoptera is shown. In addition, dietary manipulation indicated the consumption of pollen significantly increased SCP temperature. These results are discussed in the light of winter active bumblebees and climate change.

Show MeSH
Related in: MedlinePlus