About the Western Bumble Bee
Bombus occidentalis, the western bumble bee, is one of around 30 bumble bee species present in the western United States and western Canada. A recent review of all of its close relatives worldwide appears to have confirmed its status as a separate species.
Western bumble bee workers have three main color variations. The first color variation is found from northern California, north to British Columbia, and east to southwest Saskatchewan and Montana. B. occidentalis in these areas have yellow hair on front part of thorax. They are also marked by black hair segments on the basal section of the fourth abdominal segments have black hair and whitish lower edge of the fourth and fifth abdominal segments. In addition, they also have sparse whitish hairs that may appear black on the sixth abdominal segment, and an entirely black head.
The second color variation is found along the central coast in California. It has yellow hair on the sides of the second abdominal segment and all of the third abdominal segment and a reddish-brown hair on fifth abdominal segment.
The third color variation is found from the Rocky Mountains to Alaska. It has yellow hair on the thorax behind the... Wikipedia →