Data from: Colony and individual life-history responses to temperature in a social insect pollinator

1. 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. 2. This study uses the key pollinator Bombus terrestris, a eusocial bumblebee with an annual colony cycle, to determine how temperature affects life-history traits at both individual and colony levels. 3. In two laboratory experiments, we reared B. terrestris colonies at either 20 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. 4. 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. 5. 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.

1. 传粉昆虫具有重要的生态与商业价值，却可能正面临气候变化引发的生态扰动。尽管存在此类威胁，针对传粉昆虫在实验可控温度变化下的生活史响应的研究仍较为匮乏，而这对于真社会性昆虫（eusocial insects）这类具有复杂生活史的物种而言，本应具备尤为重要的参考价值。2. 本研究以关键传粉昆虫地熊蜂（Bombus terrestris）——一种具有年度蜂群周期的真社会性熊蜂——为研究对象，旨在探究温度如何在个体与蜂群层面影响其生活史性状。3. 在两项室内实验中，我们将地熊蜂（Bombus terrestris）蜂群分别置于20℃与25℃环境下饲养，并测定了一系列生活史性状的差异，包括蜂群寿命、蜂王寿命、工蜂寿命、工蜂繁育量、有性个体（蜂王与雄蜂）繁育量、生长节律，以及温度对体温调节行为的影响。4. 较高的饲养温度在其中一项实验中对蜂群寿命产生了显著的正向影响，但未显著影响蜂王或工蜂的寿命。较高的饲养温度显著提升了蜂群规模，但未改变蜂群达到峰值规模的时间。此外，较高温度下的蜂王繁育量显著更高，但未对工蜂或雄蜂的繁育量以及雄蜂繁育的时间产生影响。同时，处于较高温度环境中的蜂群，其工蜂的振翅行为显著增多，而蜡质巢盖的建造行为则显著减少。综上，饲养温度升高数摄氏度可提升蜂群寿命、蜂群规模与蜂王繁育量。不过，个体寿命并未受到影响，这或许可通过代价高昂的体温调节行为的变化得到缓冲。5. 我们据此得出结论：真社会性昆虫对气候变化背景下的预测升温可能表现出复杂的表型响应，包括对蜂群层面的生产力与繁殖的影响。在预测气候变化对关键传粉服务供给的影响时，应将此类效应纳入考量。