The Rusty-patched Bumblebee (Bombus affinis) was at one time among the more common and widespread bumblebees in eastern North America. However, this is no longer the case. The first decade of the 21st century saw growing concern about declining pollinator populations in general in several regions of the world, with particular attention focused on bees, and much of the available data on declining bee populations has focused on bumblebees. Although populations of some bumblebee species appear to be robust, many others have apparently gone extinct in recent years or suffered dramatic declines. Bombus affinis is one of several North American bumblebee species that have experienced clear declines. Colla and Packer (2008) documented an impoverishment of the bumblebee community in general in southern Ontario (Canada) between the early 1970s and the first decade of the 21st century and found that B. affinis, in particular, declined dramatically in abundance not only in southern Ontario but throughout its native range. There is evidence of declines in three other North American bumblebees as well (all four belong to the subgenus Bombus): B. franklini and B. occidentalis in the west and B. terricola in the east. Bombus franklini, which had a historically small geographic distribution, is thought to be at the brink of extinction (or possibly extinct). Bombus affinis, B. terricola, and B. occidentalis have much larger historical ranges, but have disappeared from numerous sites where they were previously common. (Colla and Packer 2008 and references therein)
No one has provided updates yet.