Abstract
Pollinating insects are of major ecological and commercial importance, yet they may be facing ecological disruption from a changing climate. Despite this threat, few studies have investigated the life-history responses of pollinators to experimentally controlled changes in temperature, which should be especially informative for species with complex life histories such as eusocial insects.
This study uses the key pollinator Bombus terrestris, a eusocial bumble bee with an annual colony cycle, to determine how temperature affects life-history traits at both individual and colony levels.
In two laboratory experiments, we reared B. terrestris colonies at either 20°C or 25°C, and measured differences in a set of life-history traits including colony longevity, queen longevity, worker longevity, production of workers, production of sexuals (queen and male production) and growth schedule, as well as effects on thermoregulatory behaviours.
Higher rearing temperature had a significant positive effect on colony longevity in one of the two experiments but no significant effects on queen or worker longevity. Higher rearing temperature significantly increased colony size but did not affect the timing of peak colony size. It was also associated with significantly higher queen production but had no effect on the production of workers or males or the timing of male production. Higher temperature colonies exhibited significantly more wing-fanning by workers and significantly less wax canopy construction. Hence an increase in rearing temperature of a few degrees increased colony longevity, colony size and queen production. However, individual longevity was not affected and so may have been buffered by changes in costly thermoregulatory behaviours.
We conclude that eusocial insects may show complex phenotypic responses to projected temperature increases under climate change, including effects on productivity and reproduction at the colony level. Such effects should be considered when predicting the impact of climate change on the provision of essential pollination services.
This study uses the key pollinator Bombus terrestris, a eusocial bumble bee with an annual colony cycle, to determine how temperature affects life-history traits at both individual and colony levels.
In two laboratory experiments, we reared B. terrestris colonies at either 20°C or 25°C, and measured differences in a set of life-history traits including colony longevity, queen longevity, worker longevity, production of workers, production of sexuals (queen and male production) and growth schedule, as well as effects on thermoregulatory behaviours.
Higher rearing temperature had a significant positive effect on colony longevity in one of the two experiments but no significant effects on queen or worker longevity. Higher rearing temperature significantly increased colony size but did not affect the timing of peak colony size. It was also associated with significantly higher queen production but had no effect on the production of workers or males or the timing of male production. Higher temperature colonies exhibited significantly more wing-fanning by workers and significantly less wax canopy construction. Hence an increase in rearing temperature of a few degrees increased colony longevity, colony size and queen production. However, individual longevity was not affected and so may have been buffered by changes in costly thermoregulatory behaviours.
We conclude that eusocial insects may show complex phenotypic responses to projected temperature increases under climate change, including effects on productivity and reproduction at the colony level. Such effects should be considered when predicting the impact of climate change on the provision of essential pollination services.
Original language | English |
---|---|
Pages (from-to) | 1209-1217 |
Journal | Functional Ecology |
Volume | 29 |
Issue number | 9 |
DOIs | |
Publication status | Published - Sep 2015 |
Keywords
- Pollination
- climate change
- bumble bees
- colony cycle
- phenology
- thermoregulation
Profiles
-
Andrew Bourke
- School of Biological Sciences - Emeritus Professor
- Centre for Ecology, Evolution and Conservation - Member
Person: Honorary, Research Centre Member