Couvillon Margaret J, Fitzpatrick Ginny, Dornhaus Anna
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA ; Laboratory of Apiculture and Social Insects, Department of Biological and Environmental Science, University of Sussex, Falmer, Brighton BN1 9QG, UK.
Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA.
Psyche (Camb Mass). 2010;2010. doi: 10.1155/2010/536430.
Bumble bees are important pollinators of crops and other plants. However, many aspects of their basic biology remain relatively unexplored. For example, one important and unusual natural history feature in bumble bees is the massive size variation seen between workers of the same nest. This size polymorphism may be an adaptation for division of labor, colony economics, or be nonadaptive. It was also suggested that perhaps this variation allows for niche specialization in workers foraging at different temperatures: larger bees might be better suited to forage at cooler temperatures and smaller bees might be better suited to forage at warmer temperatures. This we tested here using a large, enclosed growth chamber, where we were able to regulate the ambient temperature. We found no significant effect of ambient or nest temperature on the average size of bees flying to and foraging from a suspended feeder. Instead, bees of all sizes successfully flew and foraged between 16°C and 36°C. Thus, large bees foraged even at very hot temperatures, which we thought might cause overheating. Size variation therefore could not be explained in terms of niche specialization for foragers at different temperatures.
大黄蜂是农作物和其他植物的重要传粉者。然而，它们基本生物学的许多方面仍相对未被探索。例如，大黄蜂一个重要且不寻常的自然史特征是同一蜂巢内工蜂之间存在巨大的体型差异。这种体型多态性可能是对劳动分工、群体经济学的一种适应，或者是非适应性的。也有人提出，也许这种差异使得在不同温度下觅食的工蜂能够实现生态位特化：较大的蜜蜂可能更适合在较凉爽的温度下觅食，而较小的蜜蜂可能更适合在较温暖的温度下觅食。我们在这里使用一个大型的封闭生长室进行了测试，在那里我们能够调节环境温度。我们发现环境温度或蜂巢温度对飞向悬挂式喂食器并在其周围觅食的蜜蜂的平均体型没有显著影响。相反，各种体型的蜜蜂都能在16°C至36°C之间成功飞行和觅食。因此，即使在非常炎热的温度下，大蜜蜂也会觅食，而我们原以为这可能会导致过热。所以，体型差异无法用不同温度下觅食者的生态位特化来解释。
