An ordinary walk through Ithaca’s East Lawn Cemetery by a Cornell University entomology lab employee has led to an extraordinary scientific discovery, revealing the cemetery as an unprecedented sanctuary for one of North America’s largest known aggregations of ground-nesting wild bees. What began as a casual observation by Rachel Fordyce in the spring of 2022 blossomed into a groundbreaking study, estimating a staggering 5.5 million individual Andrena regularis, commonly known as the "regular mining bee," concentrated within a mere 1.5-acre area. This remarkable finding, published on April 13 in the esteemed journal Apidologie, underscores the critical, yet often overlooked, ecological importance of urban green spaces and challenges conventional perceptions of cemeteries as solely places of solemn remembrance.
The initial spark for this extensive research occurred when Fordyce, who previously saved money by parking at Ithaca’s East Hill Plaza and walking through the cemetery on her commute to a Cornell University entomology lab, noticed an unusually dense presence of bees. "Bees were everywhere," she recalled, an observation that prompted her to collect samples in a jar. She presented her findings to her supervisor, Bryan Danforth, a professor of entomology in Cornell’s College of Agriculture and Life Sciences. "These are all over the cemetery," she informed him, initiating a chain of events that would redefine our understanding of local pollinator populations.
The meticulously identified insects were confirmed to be Andrena regularis, a solitary wild bee species vital for the pollination of a wide array of crops and native flora. This seemingly minor ecological anomaly at East Lawn Cemetery has now been recognized as one of the most significant and ancient aggregations of ground-nesting bees ever documented. The sheer density of this population is astonishing; researchers estimate it to be equivalent to more than 200 honeybee hives and to exceed Manhattan’s human population by over threefold.
A Serendipitous Discovery Ignites Scientific Inquiry
The discovery was spearheaded by Steve Hoge ’24, the lead author of the study, who conducted the intensive research as an undergraduate student in Danforth’s lab. His work aimed to illuminate the biology of these often-understudied wild bees, highlighting their indispensable role as pollinators for economically significant crops, including apples, a cornerstone of New York’s agricultural economy.
"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," stated Professor Danforth, emphasizing the study’s contribution to conservation efforts.
Historical records offer a crucial timeline for this remarkable bee haven. Andrena regularis has been documented at East Lawn Cemetery since at least the early 1900s, a testament to the site’s enduring suitability as a habitat. The cemetery itself, established in 1878, boasts a long history that predates modern urban development, providing a stable and undisturbed environment for these sensitive species.
This finding strongly reinforces the emerging scientific consensus that cemeteries can serve as invaluable refuges for biodiversity, particularly in urbanized landscapes. Older cemeteries, characterized by their mature trees, unmanicured areas, and minimal human disturbance, are increasingly recognized for their capacity to harbor a diverse array of plant, insect, bird, and mammal species that might otherwise struggle to survive in surrounding developed areas.
The Cemetery’s Appeal: A Haven for the Unseen
Keven Morse, the superintendent of East Lawn Cemetery, has personally witnessed the rich biodiversity of the grounds during his family’s 46 years of managing the non-profit institution. His observations include sightings of deer, geese, hawks, foxes, coyotes, and, of course, an abundance of bees. Morse humorously noted that these numerous bees have never posed a threat to him.
Morse’s practical experience on the grounds aligns with the researchers’ conclusions. "I just felt bad having to mow in certain areas," he admitted. "There’s probably three or four sections where they really migrate heavy, there’s a lot of them." This sentiment underscores the delicate balance between maintaining cemetery grounds and protecting their natural inhabitants.
The ecological advantages offered by cemeteries like East Lawn are multifaceted. Researchers attribute their success as bee habitats to several key factors: the relative peace and quiet of these grounds, the infrequent and minimal disturbance of the soil, and, crucially, the general absence of pesticides and herbicides. These elements create an ideal, undisturbed environment conducive to the life cycle of ground-nesting bees.
Understanding Solitary Ground-Nesting Bees
While the public’s attention is often captivated by the industrious honeybee, the reality is that the vast majority of bee species worldwide—approximately 75%—are solitary ground nesters, mirroring the lifestyle of Andrena regularis. "It’s the most common lifestyle for bees," Professor Danforth explained, highlighting the underrepresentation of these crucial pollinators in public awareness and scientific literature.
Hoge’s initial foray into researching A. regularis revealed a surprising dearth of comprehensive scientific information. One of the most detailed references available dated back to 1978, presenting the research team with a significant opportunity to contribute substantially to the understanding of this species’ biology.
The life cycle of the female A. regularis is a marvel of natural engineering. She meticulously excavates individual underground nests, provisioning each chamber with a carefully collected mixture of pollen and nectar. Upon completion, she lays a single egg in each cell. These larvae then develop in complete isolation beneath the earth’s surface, feeding on their stored provisions until they mature into adult bees.
A particularly intriguing aspect of this species’ biology is its overwintering strategy. "This species overwinters as adults, which is relatively rare," Hoge elaborated. "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." This early emergence is crucial, as it synchronizes their activity with the blooming periods of early-season plants, including fruit trees and wildflowers. In the New York region, these bees typically emerge in April, coinciding with consistently warmer daytime temperatures reaching around 70 degrees Fahrenheit.
The proximity of Cornell Orchards, situated approximately one-third of a mile from the cemetery, likely plays a significant role in sustaining this immense bee population by offering a continuous and abundant source of spring floral resources. Furthermore, Professor Danforth pointed out the bees’ specific habitat preference: sandy soil, which the East Lawn Cemetery possesses in ample quantities. This geological characteristic is a vital component in the bees’ ability to construct their subterranean nests.
Innovative Methods Reveal Millions
To accurately quantify the bee population and meticulously study their emergence patterns, the research team employed a novel monitoring technique: emergence traps. These unobtrusive, small mesh tents, each covering less than one square meter of ground, are strategically placed to capture insects as they emerge from the soil. As the bees ascend, they are gently funneled into attached glass jars, allowing for precise collection and observation.
"You capture a whole community of animals coming out of the ground with this approach," Danforth remarked, underscoring the effectiveness of the method.
Between March 30 and May 16, 2023, the research team deployed ten of these emergence traps across various locations within the cemetery. The traps yielded an impressive collection of 3,251 insects, representing 16 distinct species of bees, beetles, and flies. The Andrena regularis species overwhelmingly dominated these samples, confirming its predominant presence.
By extrapolating the number of bees captured in each trap to the cemetery’s approximate 6,000 square meters, researchers calculated an average bee density. This calculation led to an estimated total population ranging from approximately 3 million to 8 million bees, with the average estimate settling at a remarkable 5.5 million individuals.
The meticulous data collected from the traps also provided valuable insights into the emergence timing differences between male and female A. regularis. Male bees were observed to emerge first, appearing during warmer periods in April, while females followed 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 explained, detailing the adaptive evolutionary strategy at play.
Parasitism and the Imperative for Conservation
The study also shed light on the ecological interactions within the bee community, documenting brood parasitism by nomad bees, specifically Nomada imbricata, also known as "cuckoo" bees. These parasitic bees exhibit a sophisticated survival tactic: they wait until A. regularis females have meticulously prepared and provisioned their underground brood cells before stealthily laying their own eggs within them.
Upon hatching, the nomad larvae are programmed to kill the host bee larvae and then consume the vital stores of pollen and nectar that were intended for the mining bee offspring. This parasitic relationship, while a natural phenomenon, highlights the complex dynamics within the cemetery’s ecosystem and the vulnerabilities faced by the native bee population.
Recognizing the critical need to protect such vital nesting sites, Danforth and his colleagues have initiated a global citizen science initiative. This program encourages the public to report any ground-nesting bee aggregations they encounter, thereby contributing to a broader understanding and mapping of these crucial habitats.
"These populations are huge, and they need protection," Danforth stressed. "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 potential loss of such a significant pollinator population due to unchecked development or habitat destruction is a stark reminder of the fragility of biodiversity and the urgent need for proactive conservation measures.
The collaborative effort behind this groundbreaking research included postdoctoral researchers Jordan Kueneman and Katherine Odanaka, undergraduate students Steve Hoge ’24 and Cassidy Dobler ’26, and lab technician Rachel Fordyce, whose initial observation sparked the entire investigation. Funding for this significant project was generously provided by the Cornell Atkinson Center for Sustainability, the National Science Foundation, and the Federal Capacity Funds program, underscoring the institutional commitment to advancing ecological research. The implications of this discovery extend far beyond Ithaca, serving as a powerful testament to the ecological value of often-overlooked urban landscapes and the profound impact of individual scientific curiosity.
