An extraordinary ecological discovery has come to light in Ithaca, New York, where researchers from Cornell University have identified one of the largest and oldest known aggregations of ground-nesting bees ever documented. The East Lawn Cemetery, a historic urban green space, is home to an estimated 5.5 million individual Andrena regularis, commonly known as the "regular mining bee," concentrated within a mere 1.5-acre area. This staggering population size is comparable to more than 200 honeybee hives and surpasses Manhattan’s human population by more than threefold, underscoring the immense ecological value of often-overlooked urban habitats.
The Unveiling of a Hidden World
The remarkable finding began with a serendipitous observation in the spring of 2022. Rachel Fordyce, then a lab technician at a Cornell University entomology lab, regularly traversed the East Lawn Cemetery as a shortcut on her commute. During one such walk, she noticed an unusual abundance of bees. Intrigued, she collected several specimens in a jar and presented them 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 reported, sparking what would become a significant scientific investigation.
Upon examination, the insects were identified as Andrena regularis, a solitary wild bee species. Unlike the communal honeybees often depicted in popular culture, Andrena regularis bees are ground-nesters, creating individual burrows in the soil. They play a vital role as pollinators for a wide array of agricultural crops and wild plants, making their concentrated presence particularly significant for local ecosystems and agriculture.
An Ecological Marvel: Scale and Significance
The initial observation quickly escalated into a comprehensive study, revealing the unprecedented scale of the bee aggregation. Led by Steve Hoge, who conducted the work as an undergraduate researcher in Danforth’s lab, the research team meticulously quantified the population. Their findings, published on April 13 in the journal Apidologie, position this aggregation as one of the largest recorded in scientific literature. "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," Hoge stated, highlighting the unique nature of their discovery.
The sheer numbers are astounding: 5.5 million bees within such a confined space. To put this into perspective, a typical honeybee hive might contain 20,000 to 80,000 individuals. The East Lawn Cemetery aggregation therefore represents an ecological equivalent of hundreds of honeybee colonies, all working tirelessly to pollinate the surrounding flora. This density not only speaks to the ideal conditions within the cemetery but also emphasizes the underappreciated abundance and ecological impact of solitary bees.
East Lawn Cemetery: An Unexpected Biodiversity Hotspot
The study delved into understanding why East Lawn Cemetery, a space primarily dedicated to human remembrance, had become such a thriving haven for these native pollinators. Historical records confirm that A. regularis has been present at the site since at least the early 1900s, suggesting a long-established and stable population within the cemetery, which itself dates back to 1878.
Researchers identified several key factors contributing to the cemetery’s suitability as a bee refuge. Foremost among these is the land’s peaceful and largely undisturbed nature. Unlike agricultural fields or manicured parks, cemeteries often receive minimal ground disturbance, allowing subterranean nests to remain intact for generations. Crucially, these sites are also typically free from the application of pesticides, which are devastating to bee populations and are widely used in other landscapes. Furthermore, the Andrena regularis species exhibits a preference for sandy soil, which the East Lawn Cemetery contains in abundance, providing ideal conditions for burrowing and nest construction.
Keven Morse, the superintendent of East Lawn Cemetery, whose family has managed the nonprofit cemetery for 46 years, corroborated the observations of a vibrant ecosystem. "And of course, bees, which he said have never stung him," Morse noted, dispelling common fears about large bee populations. He also described the challenge of balancing maintenance with conservation: "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." This sentiment highlights the growing awareness among land managers of the ecological assets within their care.
This discovery significantly strengthens the burgeoning idea that cemeteries, particularly older ones in urban and suburban settings, can serve as crucial refuges for biodiversity. Beyond bees, these green spaces are increasingly recognized for sheltering uncommon plants, insects, birds, and even small mammals, acting as vital ecological corridors and pockets of nature within developed landscapes. Dr. Eleanor Vance, an urban ecologist not affiliated with the study, commented on the broader implications: "Urban cemeteries are often surprisingly rich pockets of biodiversity. They represent historical land use patterns that preserved certain ecological conditions, acting as time capsules where nature can thrive relatively unmolested by modern intensive landscaping or development." This perspective underscores the potential for repurposing or re-evaluating urban green spaces for conservation efforts.
The Life Cycle of the Regular Mining Bee
While honeybees (Apis mellifera) garner the majority of public and scientific attention, it is crucial to recognize that approximately 75% of bee species worldwide are solitary ground nesters, much like Andrena regularis. "It’s the most common lifestyle for bees," Danforth explained, emphasizing the need to broaden our understanding and appreciation of diverse bee ecologies.
Despite their prevalence, scientific information regarding A. regularis has been surprisingly scarce. Steve Hoge found that one of the most detailed references available dated back to 1978, presenting a significant opportunity for the Cornell team to thoroughly document the species’ biology and life cycle. Female Andrena regularis bees are diligent architects, excavating individual underground nests. Within these burrows, they construct brood cells, each meticulously provisioned with a mixture of pollen and nectar. An egg is laid in each cell, and the larvae develop beneath the surface, feeding on the stored provisions, before eventually pupating and emerging as adults.
A unique aspect of A. regularis biology, as Hoge explained, is its overwintering strategy: "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." This synchronization is critical for their role as early-season pollinators. In New York, these bees typically emerge in April, precisely when daytime temperatures consistently reach around 70 degrees Fahrenheit, aligning perfectly with the blossoming of apple trees and various early wildflowers. The proximity of Cornell Orchards, located about one-third of a mile from the cemetery, likely provides an abundant and readily accessible food source, further supporting the massive bee population. Danforth also noted the bees’ strong preference for sandy soil, a geological feature that further cemented the cemetery’s suitability.
Pioneering Methods: Quantifying a Subterranean Metropolis
Estimating the population of millions of subterranean insects presents a significant methodological challenge. To accurately quantify the bee population and study their emergence patterns, the research team employed an innovative monitoring method utilizing emergence traps. These small mesh tents, each covering less than a square meter of ground, are designed to funnel emerging insects into glass jars. "You capture a whole community of animals coming out of the ground with this approach," Danforth elucidated, highlighting the method’s effectiveness in ecological surveys.
Between March 30 and May 16, 2023, the research team strategically placed 10 such traps throughout the cemetery. Over this period, they collected an impressive 3,251 insects, representing 16 different species of bees, beetles, and flies. Andrena regularis overwhelmingly dominated the samples, confirming its status as the primary resident.
Using the data collected from these traps, researchers calculated the average bee density across the cemetery’s approximately 6,000 square meters. Based on these calculations, the estimated total population of A. regularis ranged from about 3 million to 8 million bees, with an average estimate settling at a remarkable 5.5 million individuals. The traps also provided invaluable insights into the emergence timing between sexes. Male bees were observed to appear first during warmer periods in April, preceding the females by several days. This staggered emergence is a common reproductive strategy in many insect species, ensuring that males are ready to mate as soon as the females emerge, thereby maximizing their opportunities to pass on their genes. "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.
Threats and the Imperative for Conservation
Even within this seemingly thriving aggregation, the study also shed light on ecological challenges. Researchers documented instances of brood parasitism by nomad (or "cuckoo") bees, specifically Nomada imbricata. These parasitic bees do not construct their own nests; instead, they stealthily wait for A. regularis females to prepare their brood cells underground. Once the mining bee has provisioned the cell with pollen and nectar and laid her egg, the nomad bee will sneak in and lay its own egg. When the nomad larvae hatch, they mercilessly kill the host bee larvae and consume the stored pollen and nectar that was intended for the mining bee’s offspring. This parasitic relationship represents a natural regulatory mechanism within the ecosystem but also highlights the complex web of interactions that govern these populations.
Beyond natural threats, human activities pose the most significant danger to such aggregations. The vulnerability of these large nesting sites to disturbance, such as construction or widespread landscaping, is a major concern. "These populations are huge, and they need protection," Danforth urged. "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 cemetery gates. Native solitary bees like A. regularis are critical for the pollination of valuable agricultural crops, including apples, a signature commodity of New York State. The economic value of pollination services provided by wild bees is immense, contributing billions of dollars to global agriculture annually. The loss of these pollinators would have cascading effects on food security and ecosystem health.
To address these conservation concerns and help locate and protect similar nesting sites globally, Danforth and his colleagues have launched a citizen science initiative. This program encourages individuals to report ground-nesting bee aggregations they encounter, leveraging public participation to map and safeguard these vital populations. This collaborative approach recognizes that conservation efforts are most effective when supported by a broad community of observers and advocates.
Collaborative Research and Future Stewardship
The discovery at East Lawn Cemetery is a testament to collaborative research and interdisciplinary efforts. The study’s co-authors 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 catalyzed the entire project. Funding for this important research was provided by the Cornell Atkinson Center for Sustainability, the National Science Foundation, and the Federal Capacity Funds program, underscoring the broad support for ecological investigations with significant conservation implications.
This extraordinary finding at the East Lawn Cemetery serves as a powerful reminder of the hidden biodiversity thriving in unexpected places, particularly within urban environments. It elevates the importance of solitary ground-nesting bees, showcasing their abundance and critical role as crop pollinators. More broadly, it advocates for a re-evaluation of how we perceive and manage urban green spaces, recognizing their potential as vital refuges for wildlife. The call for public engagement through citizen science initiatives further empowers individuals to contribute to the protection of these essential ecosystems. As human populations continue to expand and encroach upon natural habitats, discoveries like this highlight the urgent need for thoughtful land stewardship and integrated conservation strategies to protect the unseen, yet invaluable, ecological engines that sustain our world.
