. . . . . . . . . "Bombus borealis" . . "Asclepias syriaca" . . "David Kaposi. 2016. Bombus borealis nectar plant Asclepias syriaca. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/4791486> on 05 Apr 2018." . . . . "http://iNaturalist.org is a place where you can record what you see in nature, meet other nature lovers, and learn about the natural world." .