When a Cornell University scientist made an unusual discovery in 2022, she didn’t realize it would reveal one of the largest and oldest of its kind ever documented.
That’s because when entymologist Rachel Fordyce was passing through East Lawn Cemetery while walking to work at the university, and noticed an abundance of bees in the spring air, she couldn’t have guessed that one of the largest networks of these ground-nesting bees ever seen had been hiding quietly beneath her feet, undetected for more than a century.
Fordyce collected a few of the pollinating insects in a jar and brought them back to the university’s entomology lab, where they were soon identified as specimens of Andrena regularis, better known as the “regular mining bee.” As their name entails, these little stinging insects make their homes below ground.
Now, based on Fordyce’s unique discovery, she and her colleagues have learned that one of the oldest and most extensive colonies of these ground-nesting bees ever seen has been thriving for decades under the cemetery. Based on current estimates, there may be more than 5 million of the bees present at the location, which spans around an acre and a half.
By comparison, an aggregation of bees this large exceeds the entire human population of Manhattan Island by more than three times.
A Massive Discovery
Steve Hoge, the lead author of a recent study detailing the discovery, said what Fordyce found is undeniably one of the largest bee networks known to science.
“I’m sure there are other large bee aggregations that exist around the world that we just haven’t identified,” Hoge said, “but in terms of what is in the literature, this is one of the largest.”
That isn’t to say that there hadn’t been knowledge of this species in the area already. Based on historical information the researchers uncovered, evidence of the presence of regular mining bees in East Lawn Cemetery had been documented at least as early as the beginning of the 1900s.
Although we normally associate cemeteries with death, they can actually serve as important life support systems by providing habitats for several species.
Older cemeteries—especially those in large cities—can also provide a potentially crucial refuge for not just insects, but also plants, birds, and even mammals. Among the reasons for this are that the land apportioned for cemeteries sees little disturbance over time, and in the case of insects like bees, it is free of the kinds of pesticides that can endanger them.
New Clues to the Mysteries of Bees
Although bees and other ground-dwelling insects are ubiquitous, Hoge was surprised to find how little information was available in the literature about A. regularis.
Based on one of the most detailed scientific references he found, which dates to the late 1970s, females of the species are largely credited with burrowing their nests, where eggs are deposited in chambers alongside pollen and nectar.
Their appearance in large numbers in the spring, as Fordyce noticed in 2022, is partly because the species overwinters as adults, which Hoge says “is relatively rare” for pollinators.
Another key factor regarding East Lawn Cemetery’s massive population is its proximity to Cornell Orchards, which is located less than half a mile away.
The study was carried out using small mesh emergence traps, which researchers can use to funnel insects into glass containers as they leave their underground nests. From late March until mid-May 2023, ten of these traps were used throughout the cemetery to collect more than 3,200 insects. Other species the research team captured along with A. regularis were beetles and varieties of flies, although they say bees “dominated” the samples they obtained.
The total estimated bee population the team calculated indicated an average of 5.5 million bees, although as many as 8 million of the pollinators could be hidden below the cemetery.
Citizen Scientists Becoming Involved
Other aspects of the bees’ lives, which include differences in the emergence patterns between males and females, and the phenomenon known as brood parasitism, where nomad bees (Nomada imbricata) occasionally enter the nests of A. regularis colonies and lay their own eggs inside their brood cells. Upon hatching, these larval interlopers kill the host larvae and plunder the pollen and nectar stores within the mining bee nests.
As a means of locating and protecting these beneficial pollinators and their aggregations, the research team has now appealed to citizen scientists for help with locating and reporting similar nesting sites.
“These populations are huge, and they need protection,” says Bryan Danforth, professor of entomology in Cornell’s College of Agriculture and Life Sciences.
“If we don’t preserve nest sites, and someone paves over them, we could lose in an instant 5.5 million bees that are important pollinators,” Danforth says.
Danforth and the team’s recent study, “Emergence dynamics and host-parasite associations in a large aggregation of Andrena regularis (Hymenoptera: Apoidea: Andrenidae),” appeared in the journal Apidologie.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. A longtime reporter on science, defense, and technology with a focus on space and astronomy, he can be reached at micah@thedebrief.org. Follow him on X @MicahHanks, and at micahhanks.com.