Honey bee plants of Pacific Northwest Lowlands
Bumble bees of Puget Sound Lowlands
The illustration below, crafted by Pacific Northwest Bumble Bee Atlas, showcases the color patterns of female (worker or queen) bumble bees. Keep in mind that a particular species may manifest two distinct color variations depending on its geographical location, and male bees can exhibit notably different appearances (although not depicted here). In the North Seattle area, I've encountered six species, highlighted within blue rectangles. For further exploration of bumble bee species in your vicinity, Bumble Bee Watch is a valuable resource. You can also find many bumble bee photos in Bumble bees of Washington State and BugGuide.
Six common bumble bee species in north Seattle area
The black-tailed bumble bee, Bombus melanopygus, is easily recognizable with its distinctive bright orange hair in the middle of the abdomen. In my garden, I observed its workers from mid-April to mid-June 2023, and then again in much smaller numbers from mid-November to mid-December.
The fuzzy-horned bumble bee, Bombus mixtus, is another orange-colored species. Both workers (left) and golden-colored males (right) feature orange hair at the end of the abdomen. In my garden, workers were observed from mid-May to mid-August 2023, and males from early June to mid-August.
The yellow-head bumble bee, Bombus flavifrons, was observed in my garden from mid-May to mid-August 2023 (worker, left) and mid-June to mid-August (male, right). With their long tongues, they are frequently spotted on plants with nectaries situated too deep in flowers for honey bees to reach.
The California bumble bee, Bombus californicus, is also known as a subspecies of the yellow bumble bee (Bombus fervidus sbsp. californicus). In my local area, the smaller individuals carrying pollen (workers) predominantly exhibit a dark form (left). Those displaying a lighter form (right, in fewer numbers than the dark form) likely represent males, as I have never observed them carrying pollen. Worker bees were active in my garden from late May to early October 2023, while potential males (mostly in the light form, although some dark individuals might also be males) were present from mid-July to early September. Like the yellow-head bumble bee mentioned earlier, California bumble bees are characterized by remarkably long tongues.
Last but not least is the so-called 'yellow-faced group,' consisting of two similar-looking species. Both may resemble the dark form of the California bumble bee mentioned earlier, except for the face color. The majority, more than 90% in my area, appear to be the yellow-faced bumble bee, Bombus vosnesenskii, characterized by a solid black underside of the abdomen (left). The minority seem to have light-colored hair on the underside of the abdomen (right), one of the distinguishing features of the obscure bumble bee, Bombus caliginosus, although it is possible that they are only a variation of vosnesenskii.
Feeding bumble bee queens
Bumble bee colonies, unlike honey bee colonies, follow an annual cycle where the entire colony dies out every fall. During winter, the surviving young, mated queens hibernate underground and autonomously establish new colonies in the following spring. The plants listed below are early spring and fall bloomers that attract bumble bee queens.
