Landscape composition and local floral resources influence foraging behavior but not the size of Bombus impatiens Cresson (Hymenoptera: Apidae) workers

Here, we assessed how the morphology, weight and foraging behavior of individual workers are affected by their surrounding landscape. We hypothesized that colonies established in landscapes showing high cover of intensive crops and low cover of flowering crops, as well as low amounts of local floral resources, would produce smaller workers, which would perform fewer foraging trips and collect pollen loads less constant in species composition. We tested these predictions with 80 colonies of commercially reared Bombus impatiens Cresson placed in 20 landscapes spanning a gradient of agricultural intensification in southern Québec, Canada. We estimated weekly rate at which workers entered and exited colonies and captured eight workers per colony over a period of 14 weeks during the spring and summer of 2016. Captured workers had their wing, thorax, head, tibia, and dry weight measured, as well as their pollen load extracted and identified to the lowest possible taxonomic level. We did not d...

本研究旨在探究周边景观对熊蜂工蜂的形态特征、体重及觅食行为的影响。我们提出如下研究假说：在集约化作物覆盖率高、开花作物覆盖率低且本地花卉资源匮乏的景观中建立的熊蜂蜂群，其繁育出的工蜂体型更小，且觅食频次更低，所采集的花粉团在物种组成上的稳定性也更差。本研究以80群商业化繁育的明亮熊蜂（Bombus impatiens Cresson）为实验材料，将其安置于加拿大魁北克南部20个涵盖农业集约化程度梯度的景观样地中，以此验证上述假说。2016年春夏两季的14周实验周期内，我们每周统计工蜂进出蜂群的频次，并从每个蜂群中捕获8只工蜂。对捕获的工蜂，我们测量其翅、胸部、头部、胫节的形态指标与干重，并提取其花粉团，鉴定至尽可能低的分类阶元。我们未[原文未完整提供后续内容]