Rachel Fordyce’s daily commute to her entomology lab at Cornell University once involved a frugal shortcut: parking at Ithaca’s East Hill Plaza and traversing East Lawn Cemetery on foot. It was during one such spring walk in 2022 that an extraordinary sight unfolded before her eyes. The air was alive with the buzzing of countless bees, an unusual abundance that piqued her scientific curiosity.
Collecting a sample in a jar, Fordyce brought her findings to her supervisor, Bryan Danforth, a distinguished professor of entomology within Cornell’s College of Agriculture and Life Sciences. "These are all over the cemetery," she reported, presenting her captured specimens. The insects were swiftly identified as Andrena regularis, commonly known as the "regular mining bee." This solitary wild bee species, characterized by its habit of nesting underground, plays a vital role in pollinating both agricultural crops and native flora.
What began as a serendipitous observation by a graduate student has blossomed into a landmark scientific discovery. Researchers have since revealed that East Lawn Cemetery harbors one of the largest and oldest documented aggregations of ground-nesting bees ever recorded. Scientific estimates suggest that within a mere 1.5-acre expanse, the site is home to an astonishing population of approximately 5.5 million individual bees. This density is staggering, comparable to the combined populations of over 200 honeybee hives and exceeding Manhattan’s human population by more than threefold.
"I’m sure there are other large bee aggregations that exist around the world that we just haven’t identified, but in terms of what is in the literature, this is one of the largest," stated Steve Hoge ’24, the lead author of the study detailing these findings, which was published on April 13 in the prestigious journal Apidologie. Hoge conducted this groundbreaking work as an undergraduate researcher under Danforth’s mentorship.
The Unexpected Haven: Why a Cemetery Became a Bee Metropolis
The research undertaken at East Lawn Cemetery delves into the biology of these often-overlooked solitary wild bees, while simultaneously underscoring their profound importance as pollinators for economically significant crops. Apples, a cornerstone of New York’s agricultural landscape, are among the beneficiaries of these industrious insects.
Professor Danforth emphasized the broader implications of the discovery: "The research elevates the value of solitary ground-nesting bees and shows just how abundant these bees are, how important they are as crop pollinators, and that we need to be aware of these nest sites and preserve them." Historical records provide compelling evidence of A. regularis‘ presence at East Lawn Cemetery dating back to at least the early 1900s, a testament to the site’s long-standing suitability as a habitat. The cemetery itself boasts a rich history, having been established in 1878.
This remarkable finding lends significant weight to the growing understanding that older cemeteries can serve as critical refuges for biodiversity. Urban cemeteries, in particular, are increasingly recognized for their capacity to shelter a diverse array of flora and fauna, including rare plant species, various insect populations, and even mammals like deer and foxes.
Keven Morse, the superintendent of East Lawn Cemetery, has witnessed this rich biodiversity firsthand during his family’s 46-year stewardship of the nonprofit grounds. He recounts observing a menagerie of wildlife, from deer and foxes to coyotes and hawks, alongside the ubiquitous bees. "And of course, bees, which he said have never stung him," Morse remarked, highlighting the docile nature of these pollinators. He further elaborated on the noticeable concentration of bees in specific areas, noting, "I just felt bad having to mow in certain areas. There’s probably three or four sections where they really migrate heavy, there’s a lot of them."
The unique suitability of cemeteries as bee habitats can be attributed to several factors. These tranquil landscapes are typically characterized by minimal human disturbance and, crucially, a general absence of pesticide application. This peaceful, undisturbed environment provides the ideal conditions for ground-nesting bees to establish and maintain their colonies.
Beyond the Honeybee: The World of Solitary Ground Nesters
While honeybees often capture public attention, the reality of the bee world is far more diverse. Approximately 75% of all bee species are solitary ground nesters, mirroring the behavior of A. regularis. "It’s the most common lifestyle for bees," Professor Danforth affirmed, highlighting the underappreciated ecological significance of this group.
Steve Hoge’s initial exploration into the scientific literature concerning A. regularis revealed a surprising scarcity of detailed information. The most comprehensive existing references dated back to 1978, presenting a compelling opportunity for his team to meticulously document the species’ biology.
The life cycle of the female A. regularis involves the meticulous construction of underground nests. Within these subterranean chambers, she provisions individual cells with a mixture of pollen and nectar, serving as sustenance for her offspring. Eggs are laid in these cells, and the larvae develop entirely beneath the earth’s surface before emerging as adult bees.
"This species overwinters as adults, which is relatively rare, and that’s part of the reason why they come up out of the ground so early in the spring, timed to the apple bloom," Hoge explained. This early emergence is a critical adaptation, aligning their activity with the blooming period of vital food sources. These bees are not only crucial for apple pollination but also visit a variety of fruit trees and wildflowers that bloom in the early spring. In the temperate climate of New York, they typically emerge in April, coinciding with the consistent arrival of daytime temperatures around 70 degrees Fahrenheit.
The proximity of Cornell Orchards, situated approximately one-third of a mile from the cemetery, likely plays a supporting role in sustaining this massive bee population by offering an abundant supply of spring blossoms. Furthermore, Danforth pointed out the bees’ preference for sandy soil, a geological characteristic abundant in East Lawn Cemetery, further contributing to its appeal as a nesting site.
Unveiling the Numbers: Innovative Methods for Counting Millions
To accurately estimate the bee population and meticulously study their emergence patterns, the research team employed a novel monitoring technique: emergence traps. These ingenious devices, consisting of small mesh tents covering less than a square meter of ground, effectively funnel emerging insects into collection jars.
"You capture a whole community of animals coming out of the ground with this approach," Danforth explained, underscoring the method’s comprehensive nature. Between March 30 and May 16 of 2023, the researchers strategically deployed 10 such traps across the cemetery grounds. The collected samples yielded an impressive 3,251 insects, representing a diverse community of 16 species, including bees, beetles, and flies. The overwhelming majority of these specimens were identified as A. regularis.
By extrapolating the number of bees captured in each trap to the cemetery’s estimated 6,000 square meters of suitable habitat, the researchers calculated an average bee density. This data allowed them to estimate the total population, which ranged from approximately 3 million to a remarkable 8 million individuals, with a central estimate of 5.5 million.
Beyond population numbers, the emergence traps also provided valuable insights into the timing of male and female bee emergence. The data revealed that male bees emerge first, capitalizing on warmer periods in April. Females typically follow several days later. "The males come out first and wait for the females, so that they have the best opportunities to mate and pass on their genes," Hoge elaborated on this critical reproductive strategy.
The Shadow of Parasitism and the Call for Conservation
The study also shed light on a natural threat to the A. regularis population: brood parasitism by nomad bees, specifically identified as Nomada imbricata. These "cuckoo" bees employ a cunning strategy, waiting until the female A. regularis has meticulously prepared her underground brood cells. At this opportune moment, the nomad bee lays her own eggs within these prepared cells.
Upon hatching, the nomad larvae exhibit aggressive behavior, consuming the host bee larvae and appropriating the vital stores of pollen and nectar intended for the mining bee offspring. This parasitic relationship highlights the intricate ecological dynamics at play within the cemetery ecosystem.
In response to these findings and the pressing need to protect such vital habitats, Danforth and his colleagues have initiated a global citizen science endeavor. This initiative encourages the public to report any ground-nesting bee aggregations they encounter, thereby contributing to a broader understanding and cataloging of these crucial sites.
"These populations are huge, and they need protection," Danforth stated with urgency. "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." The implications of such a loss extend far beyond the immediate ecological impact, potentially affecting agricultural yields and the health of wild plant communities.
The research team’s significant contributions were further acknowledged with the inclusion of postdoctoral researchers Jordan Kueneman and Katherine Odanaka, undergraduate students Steve Hoge ’24 and Cassidy Dobler ’26, and lab technician Rachel Fordyce as co-authors on the study. Funding for this critical research was generously provided by the Cornell Atkinson Center for Sustainability, the National Science Foundation, and the Federal Capacity Funds program, underscoring the widespread recognition of its importance. The discovery at East Lawn Cemetery serves as a powerful reminder of the hidden biodiversity that exists in unexpected places and the urgent need for conservation efforts to protect these invaluable natural resources.
