A few weeks ago, I spent an afternoon watching and photographing bumble bees at Camassia Preserve in Portland. The bees were buzzing around, collecting nectar and pollen from Indian Camas flowers (Camassia quamash), among others.
The most conspicuous species, if not the most common, was the Yellow-faced Bumble Bee (Bombus vosneskensii). This is a chunky insect, 0.4-0.8 inches long (1-2 cm). It is distinguished by the yellow hairs on its head and the single yellow/white strip across its abdomen.
The bumble bees in the two photos below are smaller species. Originally, I decided that these were Black-tailed Bumble Bees (Bombus melanopygus), but now I’m not so sure. There are several bumble bee species that look similar and may not be easily identified in the field.
The colors of the bees in these photographs appear to be different, so they may represent two different species.