two-spotted bumble bee

LC - Least Concern

N5 - Secure

SNR - Unranked

not listed

Two-spotted bumble bee is a common, small, colonial, ground-nesting bumble bee.

The female (worker) bee is 7 ⁄16″ to ⅝″ long. The upper side of the thorax is black but is densely covered with short yellow hairs. There is a small, round spot in the middle that is , more or less bare and more or less fringed with short black hairs. At the base of each wing there is a shiny, black bare plate (tegula).

There are six abdominal segments. The first segment is densely covered with yellow hairs. Segment 2 has a broad yellow spot across the middle third at the leading (anterior) edge that extends nearly to the trailing (posterior) edge of the segment. It may be indented in the middle appearing as two connected spots or a rounded “W”. Segments 3 through 6 are entirely black and densely covered with short black hairs.

The hairs on the head are mostly black. There is a dense tuft of black hairs on the top of the head (vertex) and a dense tuft of yellow hairs on the back of the head. There are two large compound eyes, one on each side of the head; and three small simple eyes (ocelli) in a triangular pattern at the top of the head between the compound eyes. The middle ocellus is larger than the the two lateral ones. The top of the small (lateral) ocelli are on a virtual line (supraorbital line) with the top of the compound eyes. The area between the bottom margin of the compound eye and the base of the mandible, called the malar space, is relatively long. The antennae have 12 segments. The first antenna segment is slightly shorter than than the second and third combined. The tongue is very long.

The wings and legs are black.

The queen is similar to the worker but larger, ⅝″ to ⅞″ long.

The male (drone) is similar but has 7 abdominal segments and 13 antennae segments. The hairs on the back of the head are yellow, like the female, but those on the front of the head are mixed black and yellow. Abdominal segments 3 through 7 have variable amounts of yellow and black hairs. Segment 2 on some individuals is entirely yellow. Segments 4 and 5 are mostly yellow on some individuals. The compound eyes are not larger than those of the female.

Queen: ⅝″ to ⅞″

Male: ½″ to 9 ⁄16″

Worker: 7 ⁄16″ to ⅝″

Brown-belted bumble bee (Bombus griseocollis) yellow spot on abdominal segment 2 is U-shaped and extends less than half way to the posterior edge of the segment. The hairs on the back of the head of the female are black. The eyes on the male are much larger.

Woodland habitats

Very early spring to mid-summer; March to September

Bumble bees will sting to protect themselves or their nest. The stinger is not barbed and the bee can sting multiple times.

Overwintering queens emerge from hibernation in March. They nest mostly underground but sometimes above ground or in cavities in dead trees.

Larvae are fed both nectar for carbohydrates and pollen for protein.

Adults feed mostly on nectar but also on some pollen. The very long tongue allows it to feed on nectar of plants with long corolla tubes.

Sources

7, 27, 29, 30.

Common in eastern North America

Some authors separate bumble bees and orchid bees into the subfamily Bombinae. NCBI follows this classification. Most authors follow Michener (2007) and include those groups in the subfamily Apinae with the honey bees.

Location: Lyndale Park, Minneapolis, MN

Location: Uncas Dunes SNA