On her way to work at Cornell University’s entomology lab, Rachel Fordyce would park at Ithaca’s East Hill Plaza and walk through East Lawn Cemetery to save money. During one walk in the spring of 2022, she noticed something unusual. Bees were everywhere.
She collected some in a jar and took it to her supervisor, Brian Danforth, a professor of entomology at Cornell University’s College of Agriculture and Life Sciences.
“These are all over the cemetery,” she told him.
The confirmed insects are normal adrenalinecommonly referred to as the “common mining bee”, is a species of solitary wild bee that nests underground and helps pollinate crops and wild plants.
That simple observation led to a surprising discovery. Researchers found that the cemetery was home to the largest and oldest population of ground-nesting bees ever recorded. Scientists estimate that the site is home to approximately 5.5 million bees, concentrated within a 1.5-acre area. That’s the equivalent of more than 200 beehives and more than three times the population of Manhattan, researchers say.
“I’m sure there are other large bee populations around the world that we just haven’t identified, but this is one of the largest based on what’s been described in the literature,” said Steve Hoge ’24, lead author of the study published April 13 in the journal. epidemiology.
Hoge conducted this research as an undergraduate researcher in the Danforth lab.
Why cemeteries have become bee havens
The study investigated the poorly understood ecology of these wild bees and also highlighted their importance as pollinators of valuable agricultural products such as apples, one of New York’s signature products.
“This study raises the value of solitary ground-nesting bees and shows how abundant these bees are, how important they are as crop pollinators, and the need for us to be aware of these nesting sites and protect them,” Danforth said.
historical records have shown that A.Regular It has existed at East Lawn Cemetery since at least the early 1900s. The cemetery itself dates back to 1878.
Scientists say the discovery strengthens the idea that cemeteries can serve as important refugia for biodiversity. Old cemeteries, especially in urban areas, are already known to be home to rare plants, insects, birds, and mammals.
Keven Morse, East Lawn Cemetery caretaker, said he has seen deer, geese, hawks, foxes, coyotes and countless bees in the 46 years his family has helped manage the nonprofit cemetery.
“And of course he said he’s never been stung by a bee.”
“I felt bad having to mow in certain areas,” Morse said. “There’s probably three or four sections that move really heavily. There’s a lot.”
The researchers explained that cemeteries make particularly good habitat because the land is peaceful, rarely disturbed, and few pesticides are used.
Most bees actually nest underground
Although honeybees receive the most public attention, approximately 75% of bee species are solitary ground nesters, such as: A.Regular.
“This is the most common lifestyle for bees,” Danforth says.
When Hoge began this type of research, he found there was surprisingly little scientific information available. One of the most detailed references dates back to 1978 and gave the research team the opportunity to document honey bee ecology in more detail.
woman A.Regular They build nests underground and place their eggs in a chamber filled with pollen and nectar. The larvae develop below the surface of the earth before emerging as adults.
“This species overwinters as an adult, but this is relatively rare, which is one reason why it emerges from the ground in early spring to coincide with apple blossom bloom,” Hoge explained.
Bees also visit fruit trees and wildflowers that bloom early in the season. In New York, it typically occurs in April when daytime temperatures begin to regularly reach around 70 degrees.
Cornell Orchards, located about a third of a mile from the cemetery, may support a large honey bee population by providing an abundance of spring flowers. Danforth also noted that bees prefer the sandy soil, which is abundant in graveyards.
How did scientists count millions of bees?
To estimate honey bee populations and study their emergence patterns, researchers used a new monitoring method using emergence traps. These small mesh tents cover less than a square meter of ground and pour the emerging insects into glass jars.
“This approach allows us to capture entire communities of animals coming out of the ground,” Danforth says.
The research team set 10 traps throughout the cemetery from March 30 to May 16, 2023. They collected 3,251 insects representing 16 species of bees, beetles, and flies. A.Regular overwhelmingly dominated the sample.
The researchers used the number of bees captured in each trap to calculate the average density of bees across the cemetery’s approximately 6,000 square meters. Based on these calculations, the total honey bee population was estimated at approximately 3 to 8 million individuals, with an average estimate of 5.5 million individuals.
This trap also revealed that males and females emerge at different times. Male bees first appeared during the warm months of April, and female bees emerged a few days later.
“The male comes out first and waits for the female, so she has the best chance to mate and pass on her genes,” Hoge said.
Bee parasites and conservation concerns
This study also documented sibling parasitism by nomadic (or “cuckoo”) bees (enslaved nomads). These bees wait until next A.Regular The female prepares a breeding cell underground before laying her eggs inside it.
Once the nomadic larvae hatch, they kill the host bee larva and consume the pollen and nectar stored for the mining bee.
To find and protect similar nesting sites, Danforth and his colleagues have launched a global citizen science initiative to encourage people to report any encounters with ground-nesting bee populations.
“These populations are huge and need protection,” Danforth said. “If we don’t preserve the nest sites and someone pavers over the nest sites, we could instantly lose 5.5 million bees, which are important pollinators.”
Co-authors of the study include postdoctoral researchers Jordan Kuneman and Catherine Odanaka, undergraduate students Steve Hoge ’24 and Cassidy Dobler ’26, and lab technician Rachel Fordyce.
Funding for this research came from the Cornell Atkinson Center for Sustainability, the National Science Foundation, and the Federal Capability Funding Program.
