Bombus affinis

The Rusty-patched Bumble Bee (Bombus affinis) is a bumble bee in the family Apinae. It is found in North America throughout the east and upper Midwest of the United States^[2] and north to in Ontario, Canada where it is considered "species at risk".^[3] It has been estimated that it has been reduced to 87% of it original population.^[2] Its historical range has included southern Ontario, east to Quebec, south to Georgia, and west to the Dakotas.^[3]

As its name suggests it has a rusty-coloured patch bordered by yellow on the first half of its abdomen. It is medium to large in sized bumble bee with an annual life cycle.^[3] It is an excellent pollinator of wildflowers, cranberries, and other important crops, including plum, apple, alfalfa, and onion seed.^[2]

Until the 1980s, it was one of the most common species of bumble bee in southern Ontario. Since then the species has had a drastic decline and it is now difficult to find in its normal range. The only locality within Ontario where the Rusty-patched Bumble Bee has been seen in the last five years is Pinery Provincial Park (Lambton County) despite widespread surveys in Ontario. The Ontario Ministry of Natural Resources has begun a recovery project aimed at protecting the species and critical habitats centred in Pinery Provincial Park.^[3] The following threats have been proposed as the cause of population decline: pathogen spillover from other species, pesticide use, and habitat fragmentation and loss.^[3]

References

Wikispecies has information related to: Bombus affinis