Overview
The yellow banded bumble bee is a highly social, eusocial, insect with a highly advanced level of social organization. They live in colonies which include a founding queen, sterile female worker bees, male bees and new queens. Yellow banded bumble bees are an important and especially effective pollinator of wildflowers and crops - many of which, birds and other animals, rely on for food. Their large, fuzzy bodies collect and move more pollen than smaller bees. They can fly in cool, rainy conditions and when light levels are lower, such as at dawn and dusk. Yellow banded bumble bees were once widely dispersed throughout the upper United States and Canada, but various stressors have resulted in a major range contraction and decrease in population numbers.
Threats to the yellow banded bumble bee are various and interconnected. We work with partner agencies and organizations to support habitat conservation and protection for the yellow banded bumble bee. Through the U.S. Fish and Wildlife Service Partners for Fish and Wildlife Program, we work with private landowners to establish and maintain high quality bumble bee habitat. National wildlife refuges manage pollinator habitat on National Wildlife Refuge System across the country, often providing refugia where habitat is lacking on the greater landscape.
Habitat loss, fragmentation and degradation reduces the amount and availability of suitable feeding, nesting and overwintering habitat. It also reduces the connectivity needed for healthy populations to expand and to maintain genetic diversity. The conversion of natural habitat to farmlands, urban and suburban areas is the primary cause of bumble bee habitat loss.
Exposure to different pesticides can cause a variety of negative impacts to yellow banded bumble bees. These impacts range from mortality to sublethal effects, like neurological impairments, reduced foraging ability, suppressed immune system, impaired reproductive system as well as decreased memory and learning ability. Pesticide exposure can reduce overall bumble bee colony health and prevent new queen production. This results in fewer new queens founding their own colonies. The neonicotinoid class of insecticides are particularly problematic for bumble bees. In addition to being sprayed as a traditional foliar or soil treatment for pest control, they are increasingly used as a prophylactic seed coating. Because neonicotinoids are long-lasting systemic insecticides, plants grown from treated seeds have neonicotinoids into plant tissues, including pollen and nectar. Neonicotinoids are also known to contaminate perennial wild plants that grow on edges of seed-treated crop fields. These chemicals also can contaminate annual and perennial ornamental plants. While the application of some traditional insecticides has decreased over the last several decades, the use of neonicotinoids has increased exponentially since their development in the early 1990s. Additionally, the widespread adoption of herbicide-resistant crops has greatly increased the use of glyphosate, which likely decreases the diversity of floral resources in agricultural landscapes. Exposure to fungicides has been found to be the strongest predictor of the deadly pathogen N. bombi in four declining bumble bee species, including the yellow banded bumble bee.
Over the past three decades, the production and global movement of managed bees, such as honey bees and commercial bumble bees, have tripled. Along with the increased deployment of managed bees, the prevalence of native, and or, non-native pathogens and parasites in managed and native bees has also increased. Pathogens and parasites in wild and managed bee populations are considered to be a significant threat to bumble bees.
There are three mechanisms of disease emergence within and between populations of managed and wild bees:
- Competitive and nutritional stress - Which increases the susceptibility of wild bees to pathogens and parasites when high densities of managed bees are introduced.
- Pathogen spillover - Which occurs when managed bees transmit pathogens or parasites to wild bees or if the pathogen or parasite is already present, artificially increases the pathogen or parasite level in the wild bee population.
- Pathogen spillback - Which occurs when a natural pathogen or parasite in the wild bee population is transmitted to a managed bee population where it thrives in the high bee densities and spills back into the wild population at unnaturally high levels.
Populations of the yellow banded bumble bee that are small, and or, isolated populations are at risk of having reduced gene flow, reduced genetic diversity from inbreeding and genetic drift. This is due to their smaller effective population size, which means the number of reproductive bees, and haplodiploidy genetic structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.
Learn more about structure , or lower genetic diversity. This is exacerbated by multiple environmental stressors. Reduced genetic diversity also leads to populations being less adaptable to ongoing environmental pressures, like habitat fragmentation, increasing temperatures, pathogens, parasites and pesticides.
Changes in climate that may affect the yellow banded bumble bee include changes in temperature and precipitation patterns. These changes can directly impact individual bees or disrupt the colony life cycle. The effects of climate change climate change
Climate change includes both global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Though there have been previous periods of climatic change, since the mid-20th century humans have had an unprecedented impact on Earth's climate system and caused change on a global scale.
Learn more about climate change may also affect the habitat conditions, including soil moisture, humidity and temperature, that are required for nesting and overwintering. They can disrupt community interactions and bumble bee food resources, like the timing, quality and quantity of flowering resources, as well as plant species composition and competition for habitat. Individual bees are well-insulated with longer hairs and are physiologically adapted to pollinate in cooler conditions. When temperatures increase and exceed 30° Celsius (86° Fahrenheit), their activity declines and they may be susceptible to overheating, even in moderately warm conditions. During extreme conditions, worker bees use their wings to fan air in the nest, but this behavioral response may limit individual workers from meeting other colony demands such as foraging or brood care, which can slow or cease. Therefore, even with nest thermoregulation, colony fitness may be reduced during periods of high temperatures. Changes in temperature and precipitation alter the bloom time, and abundance and diversity of floral resources are required at critical times of these species life cycle, such as after spring emergence and before winter hibernation. Changes in climate and phenological shifts that decrease floral diversity and abundance reduce the diet breadth necessary for healthy bumble bee colonies.
Scientific Name
Identification Numbers
Characteristics
Habitat
Yellow banded bumble bees prefer undisturbed woodlands, wetlands, prairies, and meadows. They are early-spring emerging bumble bees and are often found near forests and wetlands where the earliest flowering plants occur. Foraging habitat with abundant and diverse floral resources across the landscape is required over the entire growing season, from early spring through early fall. Like other bumblebees, the Yellow Banded Bumblebee may require floral resources that are close (< 1 km) to the nest site. Colony nest sites are located underground in downward sloping tunnels and typically in a pre-existing burrow such as an abandoned rodent nest. The transition zone between forest and grassland can be particularly valuable bumble bee nesting habitat, as well as field boundaries, meadow margins, and forest edges due to the presence of abandoned rodent nests and undisturbed habitat with diverse floral resources.
Dispersing males and future queens require habitat connectivity across the landscape to properly mate. They typically disperse in late summer-early fall and the future queens require areas rich with floral resources to build up sufficient fat reserves to survive the winter. The overwintering queen hibernates in an underground cavity she excavates in loose soil. These overwintering cavities may be located close to wooded areas due to the queen’s early spring emergence and reliance on woodland spring ephemeral flowers. The site must remain undisturbed from late fall through the spring while the queen is in hibernation.
Ecosystem with large, flat areas of grasses.
Land covered by evergreen trees in cool, northern latitudes. Also called taiga.
Physical Characteristics
Yellow banded bumble bees are middling size compared to other bumble bee species and rounded in appearance from fluffy hairs. Queens are the largest bees in the colony, followed by males and then workers. Like all bumble bees, individuals have two pairs of wings, with bodies that are divided into head, thorax and abdomen.
Measurements
Queens:
Length: 0.67 to 0.75 in (17 to 19 mm)
Abdomen width: 0.35 to 0.39 in (9 to 10 mm)
Workers:
Length: 0.35 to 0.55 in (9 to 14 mm)
Abdomen width: 0.20 to 0.28 in (5 to 7 mm)
Males:
Length: 0.51 to 0.67 in (13 to 17 mm)
Abdomen width: 0.24 to 0.31 in (6 to 8 mm)
Queens, workers and males have a similar hair color pattern. All adult yellow banded bumble bees have black hairs on their head. The front of the thorax, as well as the second and third abdomen segments, are covered in yellow hairs. Their wings are slightly brown, and the hair on the legs and base of the abdomen are black. Queens and workers have a distinct fringe of brownish-yellow hair on the fifth segment of the abdomen. Males have long yellow hair on top of the head and on the face, as well as a fringe of black-yellow hair on the fifth segment of the abdomen.
While flying, the rapid movement of yellow banded bumble bee wings produce a low buzzing sound. The buzzing sound is also produced when a foraging bee uses buzz pollination to dislodge pollen from flowers.
Similar Species
The yellow banded bumble bee belongs to a distinct subgenus, Bombus sensu stricto, which includes four other closely related bumble bee species in North America: Franklin’s bumble bee (Bombus franklini), the rusty patched bumble bee (B. affinis), the western bumble bee (B. occidentalis) and the cryptic bumble bee (B. crytarum). Yellow banded bumble bees and western bumble bees can be similarly colored where their ranges overlap. The rusty patched bumble bee and the black and gold bumble bee (B. auricomus) are similar in appearance to the yellow banded bumble bee.
Food
Yellow banded bumble bees consume pollen and nectar which provide protein, fats and carbohydrates. Abundant and diverse assemblages of native flowering of trees, shrubs and wildflowers, that bloom from early spring to fall, are necessary to provide these resources to the entire colony.
Like most bumble bees, this species can utilize many floral resources depending on the time of year and availability. However, the yellow banded bumble bee is a short-tongued species and can forage most easily at flowers with short, shallow corollas to reach pollen and nectar.
Yellow banded bumble bee queens emerge early in the spring and require early blooming flower species to restore energy for colony establishment. Early blooming plants include woodland spring ephemerals and trees, like willow (Salix), cherry (Prunus), maple (Acer), alder (Alnus), poplar (Populus), horse chestnut (Aesculus), redbud (Cercis) and sassafras (Sassafras). To survive overwintering, queens must have access to large quantities of pollen and nectar in the fall to build substantial body fat.
Life Cycle
Life span depends on the reproductive status of the individual. After pupation, adult female workers live about two weeks. Queens live about one year. Males live one to two weeks. Colonies are annual. The founding queen, female workers and males all die in the late summer or early fall. Only mated, future queens hibernate over winter and survive through the next spring and summer.
The life cycle of the yellow banded bumble bee begins when the queen emerges from her underground overwintering site in the early spring. She forages at flowers to rebuild her body fat reserves and locates a suitable nest site, building a brood chamber within the nest. The queen stores nectar and pollen in the brood chamber to feed herself while incubating eggs. The queen lays multiple fertilized eggs on top of a mass of pollen mixed with nectar, covers them with wax and then sits on the brood clump to keep the eggs warm. The eggs hatch after approximately four days and the larvae feed on the pollen mixed with nectar on which they were laid. As the larvae develop, the queen continues to guard the nest, care for the larvae and forage for nectar for herself and for pollen and nectar to feed the growing larvae.
Larvae grow in four stages, called instars. As the larvae grow, they spread out from the brood clump in the nest and spin silk cocoons in which they live until they pupate and emerge as adult female workers approximately 10 to 14 days later. After the first batch of worker bees have emerged from the nest, which is approximately three to four weeks after the colony is founded, the queen remains in the nest to lay eggs and care for the young. The new workers divide the colony duties, with some bees predominantly foraging for pollen and nectar, while others help the queen tend the developing brood and guard the nest.
As mid to late summer arrives, the queen begins to lay unfertilized eggs that develop into fertile males and fertilized eggs that develop into fertile female larvae. These female larvae develop into future queens, as a result of receiving more food over a longer period of time, and by receiving pheromonal cues from the queen. Once the future queens leave the nest, they forage heavily at flowers to build up significant fat reserves to survive overwintering. Future queens and males leave the nest to mate with individuals from other colonies. The newly-mated, potential new queens continue foraging until locating a suitable overwintering site. The founding queen, workers and males from the original colony all die off in the fall and early winter.
In early spring, the solitary queen emerges from hibernation and finds a nest site. She begins laying eggs that are fertilized by sperm stored since mating the previous fall and rearing the young. Worker bees hatch and the colony grows as the workers collect food, care for the young and defend the colony. In late summer, future queens, meaning fertile females, hatch from fertilized eggs. These female larvae develop into future queens as a result of receiving more food over a longer period of time and by receiving pheromonal cues from the queen. The queen also lays unfertilized eggs at this time which will develop into fertile males. Future queens and males disperse from the nest to mate with individuals from other colonies. Dispersal distance may be up to 10 kilometers (6.2 miles). Each future queen mates only once with one male. In late fall, the founding queens, workers and males die. The new queens overwinter and begin the cycle again in spring.
Behavior
Yellow banded bumble bees are eusocial insects, meaning that they have a highly advanced level of social organization. They live in colonies which include a founding queen, sterile female worker bees, fertile future queens and fertile male bees. All individuals are offspring of the founding queen. Among the worker bees, there is division of labor and one generation caring for the next. The founding queen and later the worker bees forage for pollen and nectar from early spring to fall to provide food for the colony. Because colonies are annual with only future queens surviving the winter, yellow banded bumble bees do not produce and store honey.
Foraging individuals are generally docile. They are efficient foragers, relying on individual experience, memory and pheromonal signals. Individuals gather information from the environment and return to the nest with the odor of a new food source. These returning individuals run across the nest, fan their wings and bump into nestmates, which releases pheromones that stimulates more foragers to visit the new food source. The recruitment system does not include precise food locations, so they must rely on their memory and searching ability to find the food source.
Yellow banded bumble bees, like some other bumble bees, exhibit buzz pollination. During buzz pollination, the bee grabs the pollen producing structure structure
Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.
Learn more about structure of the flower in her jaws and vibrates her wing muscles. This buzzing vibration dislodges pollen from flowers that other bees, such as honey bees, are not able to dislodge. Yellow banded bumble bees can forage in cool and rainy weather, as well as during dawn and dusk when other pollinators are not active.
Geography
The yellow banded bumble bee was once common throughout its range, and were historically found in 25 United States and 12 Canadian provinces. In recent decades, their range has receded in the southern and far western areas. It appears to have been extirpated from much of the Pacific Northwest, Southern Appalachians and Southeast Plains, and may be more patchily distributed where it remains. This range contraction represents a loss of approximately 1,519,854 square miles.
Timeline
Explore the information available for this taxon's timeline. You can select an event on the timeline to view more information, or cycle through the content available in the carousel below.
2 Items