Franklin's bumblebee [SEP] IUCN conservation status
Franklin's bumblebee
Franklin's bumblebee ("Bombus franklini") is known to be one of the most narrowly distributed bumblebee species, making it a critically endangered bee of the western United States. It is known only from a area in southern Oregon and northern California, between the Coast and Sierra-Cascade mountain ranges. It was last seen in 2006. Franklin's bumblebee is known to collect and nectar pollen from several wildflowers, such as lupine, California poppy, and horsemint, which causes it to be classified as
. Nest architecture is simple, limited by the size of the pre-existing nest cavity, and colonies rarely last more than a year. In 2011, the International Union for Conservation of Nature set up the Bumblebee Specialist Group to review the threat status of all bumblebee species worldwide using the IUCN Red List criteria.
There are many more species of primitively eusocial than highly eusocial bees, but they have been studied less often. Most are in the family Halictidae, or "sweat bees". Colonies are typically small,