Flicker Nathaniel Ryan, Poveda Katja, Grab Heather
Department of Entomology, Cornell University, Ithaca, NY.
Environ Entomol. 2020 Feb 17;49(1):197-202. doi: 10.1093/ee/nvz141.
Industrial hemp, Cannabis sativa (Cannabaceae), is a newly introduced and rapidly expanding crop in the American agricultural landscape. As an exclusively wind-pollinated crop, hemp lacks nectar but produces an abundance of pollen during a period of floral dearth in agricultural landscapes. These pollen resources are attractive to a range of bee species but the diversity of floral visitors and their use of hemp across a range of agricultural contexts remains unclear. We made repeated sweep net collections of bees visiting hemp flowers on farms in New York, which varied in both landscape context and phenotypic traits of hemp varieties. We identified all bee visitors to the species level and found that hemp supported 16 different bee species. Landscape simplification negatively impacted the abundance of bees visiting hemp flowers but did not affect the species richness of the community. Plant height, on the other hand, was strongly correlated with bee species richness and abundance for hemp plots with taller varieties attracting a broader diversity of bee species. Because of its temporally unique flowering phenology, hemp has the potential to provide a critical nutritional resource to a diverse community of bees during a period of floral scarcity and thereby may help to sustain agroecosystem-wide pollination services for other crops in the landscape. As cultivation of hemp increases, growers, land managers, and policy makers should consider its value in supporting bee communities and take its attractiveness to bees into account when developing pest management strategies.
工业大麻，即大麻（大麻科），是美国农业领域新引入且迅速扩张的一种作物。作为一种完全靠风媒传粉的作物，大麻没有花蜜，但在农业景观中花期匮乏的时期会产生大量花粉。这些花粉资源对一系列蜜蜂物种具有吸引力，但在不同农业环境下，访花者的多样性以及它们对大麻的利用情况仍不明确。我们在纽约的农场对访大麻花的蜜蜂进行了多次扫网采集，这些农场在景观环境和大麻品种的表型特征方面都存在差异。我们将所有访花蜜蜂鉴定到物种水平，发现大麻能吸引16种不同的蜜蜂物种。景观简化对访大麻花的蜜蜂数量产生了负面影响，但并未影响群落的物种丰富度。另一方面，对于种植较高品种大麻的地块，株高与蜜蜂物种丰富度和数量密切相关，较高品种吸引的蜜蜂物种更为多样。由于大麻具有独特的开花物候期，它有可能在花期稀缺时为多样化的蜜蜂群落提供关键的营养资源，从而有助于维持景观中其他作物的全农业生态系统授粉服务。随着大麻种植面积的增加，种植者、土地管理者和政策制定者应考虑其在支持蜜蜂群落方面的价值，并在制定害虫管理策略时考虑到大麻对蜜蜂的吸引力。
