The Rusty Patched Bumble Bee is one of the main goals of Wild South’s citizen science project, but it’s not the only thing that the project is trying to find. Several other species found in our region are at risk of extinction or currently suffering population declines. We can find out how the ranges of these species are changing and what we can do to protect them before it’s too late by making as many observations of all species of Bumble Bee on iNaturalist as we can.
The IUCN Red List is used by the Xerces Society for Invertebrate Conservation to keep a list of the Bumble Bee species they think are most likely to go extinct. Here, we’ll talk about the species that live in our Southeast and are very important for us to find. Watch for these important species on your next hike or even in your flower garden, and don’t forget to add your photos to the iNaturalist project!
Bumble bees are an iconic sight across the landscapes of South Carolina. Their distinct fuzzy striped bodies provide an unmistakable buzz as they dutifully go about their work pollinating flowers and crops. Though they may seem ubiquitous, bumble bees actually face some concerning population declines. Understanding the unique life cycle and habits of South Carolina’s bumble bees can help illuminate why they are so critical to ecosystems and agriculture in the state.
The Annual Life Cycle
Unlike honey bees, bumble bees have an annual seasonal life cycle. Only fertilized queen bumble bees survive the winter. When warmer weather arrives in early spring these queens emerge and begin searching for nest sites. Nest locations include abandoned rodent burrows, compost piles, hollow logs, and other insulated, protected spots.
Once a suitable nest is established, the queen starts laying eggs and provisioning the larvae with pollen and nectar These first offspring that hatch are smaller female worker bees The queen remains in the nest incubating eggs while the workers take over foraging for food.
By late spring, the nest size grows, with up to 150 workers caring for young. The queen switches to laying unfertilized eggs that become male drone bees. Some larger females are also bred to become next year’s queens.
By fall, the founding queen, workers and males all perish leaving only the newly bred queens to survive the winter. The cycle then repeats the following spring. Sadly, many queen bees fail to make it through harsh winters.
Feeding Behaviors
Bumble bees visit flowering plants to gather nutrient-rich pollen and sugary nectar that fuels their energy needs. Their feeding behaviors also facilitate pollination. As they move from bloom to bloom, pollen grains stick to their fuzzy hair and get transferred to other flowers.
Certain plants rely almost exclusively on bumble bees for fertilization. Bumble bees are able to perform a behavior called buzz pollination. They rapidly contract their wing muscles while clutching a flower. This vibration dislodges pollen that other insects can’t access.
Tomatoes and peppers are two crops greatly benefited by buzz pollination. Greenhouse tomato operations often bring in commercially bred bumble bee hives to maximize fruit yields.
Declining Numbers
Researchers have documented significant declines in bumble bee populations across North America. Habitat loss from development and agriculture are primary culprits. Pesticides and disease also weaken colonies. Climate change threatens to shrink ranges for temperature sensitive species.
At least four bumble bee species native to South Carolina are federally listed as endangered or threatened. Without dedicated conservation efforts, more types of bumble bees face an uncertain future. Home gardeners can help by planting pollinator-friendly flowers and avoiding pesticide use. Protecting grasslands and forest edges where bumble bees nest is also beneficial.
Identifying Common South Carolina Species
South Carolina is home to around 25 different species of bumble bees. Here are some of the most frequently encountered:
-
Brown-belted Bumble Bee: This fat fuzzy bee has a brown band between its yellow and black abdomen. It nests underground and visits many flowering plants.
-
Common Eastern Bumble Bee: True to its name, this is the most abundant species in the state. Look for the yellow fringe on the first abdominal segment.
-
Southern Plains Bumble Bee: This small species has a compact oval head and short wings. It emerges very early in spring to start nesting.
-
Yellow Bumble Bee: Only the queen and male bees of this species have a vibrant yellow head and thorax matching the abdomen. Workers are black.
-
Half-black Bumble Bee: The front half of this bee’s abdomen is yellow and the back half is black. It’s one of the latest spring emerging species.
Appreciating Their Role
Bumble bees clearly contribute immense value to South Carolina through pollination services. We must protect these vulnerable creatures and appreciate their unique natural behaviors. Take time to observe bumble bees in your garden and let them fuel your fascination. With a declining population, we should treasure every fuzzy buzzing visitor.
Rusty Patched Bumble Bee
Because they are the first species of bumblebee to be put on the US Endangered Species List, our project is all about the Rusty Patched Bumblebee. In the last 2020 years, this species’ relative abundance has dropped by up to 2095%, and their once-vast range has shrunk by 70–87%.
For some reason, they haven’t been seen in the Southern Appalachians since 2004, but there could still be a population there! Look for them on wildflowers, especially in the areas shown here.
The Yellow-banded Bumble Bee’s recent population drop has mostly happened in the southern part of their range. They used to be common in agricultural areas, but now they only live in small groups. This means that many farmers have to rely on hives that they keep inside their farms.
This bumblebee helps potatoes, alfalfa, raspberries, and cranberries grow, so keep an eye out for them next time you’re in the garden.
This species is only now starting to go out of style, so now is the best time to find and protect the Yellow Bumble Bee. These Bumble Bees live along the northern border of the United States and follow the Appalachian Mountains into South Carolina. They are in danger of going extinct.
The plants that yellow bumble bees like to visit most are thistles, clovers, and bee balms that grow in meadows and open fields.
Southern Plains Bumble Bee
The number of Southern Plains Bumble Bees has dropped by about 30% in the last ten years as the open plains they depend on for food have been turned into farms. They are on the IUCN Red List as an endangered species because of these drops, but they are not yet protected by the US Endangered Species Act. Finding (or not finding) this species could lead to steps being taken to protect their weak habitat.
Southern Plains Bumble Bees live in the Southeast along the coast and west to the edge of the Appalachians. Look for them on prairie walks or in urban gardens.
Even though the American Bumble Bee has been around for a long time, it is still vulnerable to the same declines that other Bumble Bee species are facing. In the first half of the twentieth century, 30-45% of all Bumble Bees recorded were this species. Today, they make up only about 5% of all observations.
American Bumble Bees can (hopefully) be found in open farmland and fields across nearly all of North America.
It is not possible for Cuckoo Bumble Bees to raise their own young. Instead, they lay their eggs in the colonies of other species of Bumble Bees and use their resources while raising larvae that are not their own. Often, a species of Cuckoo Bumble Bee is dependent on only one or two non-parasitic species. When one declines, so does the other.
South Carolina Honey Bees
FAQ
What month are bumble bees most active?
What are the big bees in SC?
Is a bumble bee aggressive?
How do I get rid of bumble bees in my backyard?