Two-spotted Bumble Bee, Bombus bimaculatus
Excerpted from Bumble Bees of Wisconsin
Bombus bimaculatus populations are also stable. Queens of this species are the first to emerge in the
Spring, and can be found foraging on woodland ephemerals like Dutchman’s Breeches.
Body hair long and uneven. Thorax mostly yellow, with a circular patch of all black hairs between the
base of the wings. First abdominal segment fully yellow, with a “W” or two-spotted yellow patch of hair
in the middle of the second abdominal segment. While generally similar to workers and queens, males
have variable and sometimes non-symmetrical coloration patterns. Males typically with some yellow
hairs on the front of the face. Males also lack corbiculae, or the flattened midleg of the hind leg used for
transporting pollen.
Bombus bimaculatus has a shorter colony cycle, with peak worker numbers in the end of June and
early July. Queens are first to emerge after warm weather has returned (concurrent emergence with
spring ephemerals). New queens and drones can be found from early July to August.
Generally south of the tension line (Wausau/Stevens Point and farther south). However, this species
appears to be expanding its range and does well in the agricultural areas of the state.
Thistle
St. John’s Wort
Sweet Clover
Buzz Pollination
Slo-Mo Footage of a Bumble Bee Dislodging Pollen
Look Inside a Bumblebee Nest
How to Build a Bumble Bee House
Development of Colony and Nest in the Bumblebee