Bumblebees Quick ID

Quick ID
Bumblebees of Southern Ontario

Males have one more abdominal segment than females. All males, except the cuckoo males and the Black and Gold Bumblebee B. auricomus have yellow on the lower face and yellow fringe on underside of thighs (femora).
Identified by yellow/red stripes on abdomen:

One Yellow Stripe:
Common Eastern Bumblebee B. impatiens – segment 1 is yellow.

One and a half Yellow Stripes:
Two-spotted Bumblebee B. bimaculatus – segment 1 yellow; segment 2 yellow is restricted to centre of segment with straight side edges on the yellow stripe, unlike the Brown-belted. Sometimes the male has an additional stripe on segment 4. All three: queen, male and worker have yellow on top of head.

Brown-belted Bumblebee B. griseocollis – segment 1 yellow; segment 2 is yellow to yellowish-brown, restricted to centre of segment with yellow sides rounded and curving up and out to base of the segment.
Note: Male and worker segment 2 are usually yellowish-brown, but this darker colour is not obvious on the queen. Male has very large eyes.

Two Yellow Stripes:
Half Black Bumblebee B. vagans – segments 1 and 2 are yellow. Centre of thorax largely black – larger bees, fly earlier than Sanderson’s Bumblebee B. sandersoni. Sanderson’s is indistinguishable from the Half Black.

Sanderson’s Bumblebee B. sandersoni – segments 1 and 2 are yellow. Centre of thorax largely black – smaller bees, fly later than the Half Black.

Confusing Bumblebee B. perplexus female – segments 1 and 2 are yellow. Thorax completely yellow or with a tiny centre black spot.

Rusty Patched Bumblebee B. affinis – segments 1 and 2 are yellow. Reddish bar on lower border, centre of segment 2. Listed as endangered and restricted to Pinery Provincial Park, Grand Bend in Ontario.

Black and Gold Bumblebee B. auricomus female – segments 2 and 3 are yellow. Segment 1 is black but usually has yellow at side edges. Thorax yellow with a wide black bar between wing bases; lower thorax variable, yellow is mixed with black. Worn workers are easily confused with the American Bumblebee B. pensylvanicus when lower thorax yellow hairs have worn off. Best ID’d by abdominal stripes (American B. pensylvanicus has 3 yellow stripes).

Yellow-banded Bumblebee B. terricola – segments 2 and 3 are yellow; yellow fringe on tip of abdomen. Male may also have yellow on  side edges of last two segments. Thorax has narrower yellow stripe across the segment, before wing bases; rest of thorax black.

Three Yellow Stripes:
American Bumblebee B. pensylvanicus female – segments 1 to 3 yellow. Thorax base yellow; lower half of thorax black, sometimes with a very light sprinkling of yellow. Easily confused with Black and Gold Bumblebee B. auricomus – difficult to tell if first segment is entirely yellow, or just the side edges are yellow.

Black and Gold Bumblebee B. auricomus male – segments 1 to 3 are yellow. Thorax yellow with black bar between wing bases, lower edge of the black bar is V-shaped. Lower thorax has yellow tuft of hair on each side of black V-shape. No yellow hair on underside of thighs (femora).

Confusing Bumblebee B. perplexus male – segments 1 to 3 yellow. Segment 3 usually yellow in centre only. Thorax completely yellow or a tiny centre black spot.

Two-spotted Bumblebee B. bimaculatus male sometimes has a yellow stripe on segment 4 in addition to yellow stripes on 1 and 2.

Four Yellow Stripes:
Yellow Bumblebee B. fervidus female – segments 1 to 4 yellow. Thorax yellow with black bar between wing bases.

American Bumblebee B. pensylvanicus male – segments 1 to 4 yellow.  Segments 5 to tip may have yellow at sides edges; tip yellow. Lower thorax black with yellow fringe at end. Easily confused with the male Yellow Bumblebee B. fervidus which has last 2 segments entirely black.

Tri-colored Bumblebee B. ternarius – segment 1 yellow, 2 and 3 orangish, 4 yellow. Male has yellow at side edges of 5 to tip.

Red-belted Bumblebee B. rufocinctus female – segments 1 and 2 yellow, 3 and 4 orangish. Yellow tufts at side edges of 5.

Five Yellow Stripes:
Yellow Bumblebee B. fervidus male – segments 1 to 5 yellow; last 2 segments entirely black. Thorax yellow with a black bar between wing bases. American Bumblebee B. pensylvanicus male has some yellow on last 2 to 3 segments.

Red-belted Bumblebee B. rufocinctus male – segments 1 and 2 yellow, 3 and 4 orangish. Segment 5 can be yellow or orange. Some can have entirely light yellow stripes on all segments. They have very large eyes.

Bombus pensylvanicus

American Bumblebee
Bombus pensylvanicus

American Bumblebee Bombus pensylvanicus male
American Bumblebee Bombus pensylvanicus male on New England Aster. Sept 24, 2011. Wheatley, Ontario.
American Bumblebee Bombus pensylvanicus male
American Bumblebee Bombus pensylvanicus male on New England Aster. Sept 24, 2011. Wheatley, Ontario.
American Bumblebee Bombus pensylvanicus queen
American Bumblebee Bombus pensylvanicus queen on Purple Coneflower. July 15, 2006. Wheatley, Ontario.

Identification:
Queen & Worker:
Head: Entirely black, sometimes with few gray hairs above base of the antenna.
Thorax: Base yellow to wing bases; last half mainly black; a few yellow mixed with black at end. Hair longer and thicker on worker.
Wings: Dark with black veins.
Legs: Black; fringe long, black.
Abdomen: Segments 1 to 3 are yellow. 4 to 6 are black.

Male:
Head: Face and cheeks have grey-white hairs with some black hairs intermixed. Top of head has black hair. Face not as black-looking as the Yellow Bumblebee B. fervidus.
Thorax: Yellow with black stripe between wing bases. Black stripe can extend to thorax end, but always with some yellow.
Wings: Dark
Legs: Black. Fringe on underside of thighs (femur) pale yellowish. Also pale yellowish pile on underside of hind shins (tibiae).
Abdomen: Abdominal segments 1 to 4 have dense, yellow, long drooping hairs. 5 can be yellow or black. 6 and 7 mostly black with yellow on the sides of the segments. Yellow hair at centre of abdomen tip.

Similar Species: Males are difficult to separate from The Yellow Bumblebee B. fervidus. B. fervidus has last 2 abdominal segments entirely black.

Size: Queen 22 to 25.5 mm. Worker 14 to 19 mm. Male 18 to 21.5 mm.

Flight Time: June through the end of September.

Habitat: Meadows, weedy fields, open areas, gardens.

Food: Generalist pollen and nectar feeders using a wide variety of flowers.

Life Cycle: Nests under a heavy mat of grass. Hibernating queens appear in spring and establish nests at ground level in grass tussocks, often on south-facing slopes. Sometimes on or beneath the surface of the ground. Also recorded nesting in an abandoned squirrel nest. She builds a wax honey pot and fills it with honey and pollen, then lays a batch of eggs on the pollen, covering them with a waxed sheet. Eggs are incubated by the female by warming her body temperature and laying on top of the eggs. Hatched larvae (up to 40) are continually fed by the queen. The first brood become workers and take over nest maintenance and honey & pollen foraging. Males help incubate pupa in the nest. The old Queen, workers and males die by the end of the season. Only mated females live to hibernate in sheltered locations until the next spring. Life span, except for mated females is 14 to 25 weeks.

Comments: Essex County – Ojibway Prairies. The American Bumblebee is a southern species at the northern limits of its range in south-west Ontario.