The two-spotted bumblebee is one of several species of bumblebees that occur in Missouri. It has a wide distribution across the eastern United States and is relatively common in our state.
Like other species of bumblebees, they are large fuzzy or hairy bees. Bumblebees (genus Bombus) always have some fuzz on the abdomen. Females have pollen baskets on the last pair of legs.
As with other bumblebee species, the (female) workers, queens, and males can look different. Because the queens and males aren’t seen as frequently as the workers, identifications usually focus on the workers.
- The fastest way to determine the species of Missouri’s bumblebees is to look at the color patterns of the hairs on the head, the thorax, and the abdominal segments (called tergites) (the abdomen is the third, obviously segmented, part of the body, behind the head and thorax). The first abdominal segment, closest to the thorax, is called “T1” for “tergite 1.” The second segment is “T2,” etc. Female bumblebees have six tergites; males have seven.
To distinguish worker two-spotted bumblebees from other Missouri bumblebees, view the insect from above, and look at the hairs on the abdomen: First, note that T1 is covered with yellow hairs. Then, note that T2 has black hairs except for a yellow rounded W shape, which looks something like two yellow spots.
Other key identifiers:
- The sides of T2 have black hairs.
- The front of the face has a noticeable patch of yellow hair.
- The top of the head has yellow hairs.
- The bare black spot that develops on the thorax (between the wing bases) is generally circular.
Learn more about bumblebees (genus Bombus) on their group page.
Learn more about bumblebees and other apid bees (family Apidae) on their family page.
Similar species: The brown-belted bumblebee (Bombus griseocollis) is perhaps most similar; on it, the yellowish hairs on T2 appear more brownish and resemble a crescent or wide U shape (instead of a rounded W); also, that brownish crescent extends farther toward the sides, looking more like a band, and it does not extend as far hindward. Finally, the hair on top of the head of the brown-belted bumblebee is black (not yellow).
Body length (not counting appendages): ⅜ to ⅝ inch (workers); ⅝ to ⅞ inch (queens); ⅝ inch (males).
Statewide.
Habitat and Conservation
This species is widespread in North America and lives in a variety of habitats. As with many other bees, two-spotted bumblebees prefer open habitats with plenty of wildflowers: prairies and other grasslands, sunny wetlands, pastures, roadsides and railroads. They also can be found in urban and suburban areas where flowers grow.
Food
The two-spotted bumblebee is relatively small for a bumblebee, but it has a rather long tongue; therefore, it excels at visiting the tubular flowers of mint-family members. Favorite flowers include mints such as beebalm, horsemint, and wild bergamot (genus Monarda) and dead nettle.
They also visit a wide variety of other flowers: sunflower family members such as thistles and coneflowers, legumes such as clovers and hairy vetch, plus columbines, various milkweeds, Dutchman’s breeches, bluebells, wild hyacinth, wild larkspurs, woollen breeches, and more.
In early spring, the queens join many other early-emerging pollinators in visiting spring-flowering trees such as wild plums, serviceberry, buckeyes.
Status
Native Missouri bumblebee.
Life Cycle
This bumblebee usually constructs its nests underground, occupying old rodent burrows, or else in other cavities, such as in hollow logs.
Queens, having mated in the fall, hibernate during winter and emerge in early spring. They locate an acceptable nest site, gather pollen and nectar to store in the nest, and lay eggs.
The first eggs to hatch will all develop into female workers, which do not reproduce. Upon hatching, the young are grublike larvae. They eat the pollen and nectar, then pupate; they emerge as winged adult worker bees that perform most of the tasks for the colony: caring for the young, foraging, defending the colony, and so on. With workers to take care of those activities, the queen can focus on laying eggs.
Beginning in late June and into July, the queen lays eggs that will become males and queens, which, when mature, leave the nest to mate. The young queens feed heavily, to have energy to survive winter as well as to develop eggs for the next spring’s brood.
Except for the new young queens, which will hibernate until spring, all the bees of the colony die as winter begins.
Human Connections
Bumblebees are important pollinators, which is important for human agriculture, horticulture, and the environment. Some plants can only be pollinated by bumblebees. Red clover, an important fodder and traditional medicinal plant, is rarely pollinated by other bees.
The Missouri Bumble Bee Atlas is a statewide community science project aimed at tracking and conserving Missouri's native bumblebees. Learn how you can participate in this program, and download a free training packet, including a quick identification guide to Missouri's bumblebees, on its website. MDC is one of the sponsors of this citizen-science initiative.
Bumblebees are capable of stinging, if molested or if their nest is endangered, but you need not fear them; they are not aggressive.
Considering that many bumblebees are declining, if you find a bumblebee nest on your property, leave the nest alone and consider yourself lucky. Watch the bumblebees over the course of the season; take pictures!
Ecosystem Connections
Holes in the ground are easy to overlook, but they are an important home for many animals, often a succession of them. A hole may begin as the system of rotted taproots from a large tree that has died. In addition to bumblebees, rodents, shrews, gartersnakes, yellowjackets, and many other animals take advantage of these ready-made basement apartments.
Bumblebees, like many other pollinators, have certain plants that depend only on them for pollination. In fact, bumblebees are one of the main pollinators that use a technique called buzz pollination to force the anthers of certain flowers to release pollen.
- These are usually tubular flowers with small openings, and the pollen is usually stuck firmly on the anthers. The bumblebee or other buzz pollinator rapidly vibrates its flight muscles, shaking pollen from the anthers. With the pollen attached to their bodies, they visit another flower and cross-pollinate it.
- Honeybees cannot accomplish buzz pollination. Southern wild senna, partridge pea, and closed (bottle) gentian are just a few Missouri wildflowers that require buzz pollination.
In addition to the plants they pollinate, bumblebees have many other interrelationships with organisms that most of us are scarcely aware of — their predators, their parasites, and the many non-stinging insects that can survive, in part, because they mimic them. All of these have their own roles in the chain of life.
- This species is one of the bumblebees that can be parasitized by thick-headed flies (or conopid flies, family Conopidae). These flies ambush bumblebees and inject their eggs into their bodies. The grublike larval conopid develops gradually inside the living bumblebee and eventually kills it. In some bumblebee species, the presence of a nearly grown larva of canopid species Physocephala tibialis induces the soon-to-die bee to burrow into the ground, digging its own grave. Being underground protects the canopid larva as it polishes off the bee and pupates through winter. About 70 percent of two-spotted bumblebees parasitized by this species succumb to this “grave-digging mind control.”
