A routine commute through Ithaca’s East Lawn Cemetery in the spring of 2022 led to an extraordinary scientific discovery that has reshaped understanding of wild bee populations and the ecological value of unexpected urban habitats. Rachel Fordyce, then a lab technician at a Cornell University entomology lab, noticed an unusual abundance of bees during her walk from East Hill Plaza to work. This seemingly simple observation catalyzed a research effort that identified one of the largest and oldest known aggregations of ground-nesting bees ever documented, an estimated 5.5 million individual "regular mining bees" ( Andrena regularis) concentrated within a 1.5-acre area. This staggering number is comparable to over 200 honeybee hives and significantly surpasses the human population of Manhattan, underscoring the immense scale of this hidden ecological treasure.
The Serendipitous Discovery and Unfolding Research
The journey to this groundbreaking revelation began modestly. Fordyce, accustomed to her scenic shortcut through the cemetery, observed the remarkable density of bees during one particular walk. Intrigued by the sheer numbers, she collected several specimens in a jar and brought them to her supervisor, Bryan Danforth, a distinguished professor of entomology in Cornell’s College of Agriculture and Life Sciences. Her simple statement, "These are all over the cemetery," set in motion a comprehensive study that would captivate the scientific community.
The initial identification confirmed the insects as Andrena regularis, a solitary wild bee species known for nesting underground. Unlike the more commonly recognized honeybees, A. regularis does not form colonies but rather individual females construct and provision their own nests. These bees are crucial pollinators for a variety of crops and wild plants, including New York’s economically significant apple orchards.
The subsequent research, primarily spearheaded by Steve Hoge ’24, then an undergraduate researcher in Danforth’s lab, delved into the biology and ecology of this massive aggregation. Hoge’s work culminated in a study published on April 13 in the journal Apidologie, providing the first detailed scientific account of this phenomenon. The study’s findings not only illuminate the sheer scale of the aggregation but also emphasize the critical, yet often overlooked, role of solitary bees in maintaining ecosystem health and supporting agricultural productivity.
Unearthing Millions: The "Regular Mining Bee" and Its Vital Role
The Andrena regularis, or regular mining bee, represents a significant portion of global bee diversity. While honeybees ( Apis mellifera) garner most public attention, they constitute only a tiny fraction of the world’s estimated 20,000 bee species. In reality, about 75% of bee species are solitary ground-nesters, making A. regularis a prime example of the most common bee lifestyle. These bees play an indispensable role in ecosystems worldwide, contributing significantly to the pollination of both wild flora and agricultural crops. Their distinct life cycle and preferences for specific environmental conditions make them unique and valuable.
Female A. regularis meticulously construct individual nests underground, typically comprising a main tunnel with several lateral chambers. Each chamber is provisioned with a ball of pollen and nectar, collected from various flowering plants, which serves as the sole food source for a single developing larva. An egg is laid on this provision mass, and the larva then consumes it, developing through several instars before pupating. One particularly intriguing aspect of A. regularis biology, as highlighted by Hoge, is their overwintering strategy. Unlike many other bee species that overwinter as larvae or pupae, A. regularis overwinters as adults. This allows them to emerge exceptionally early in the spring, perfectly timed to coincide with the bloom of crucial early-season flowers, including apple blossoms.
In New York, these bees typically emerge in April, when daytime temperatures consistently reach around 70 degrees Fahrenheit (21 degrees Celsius). This early emergence makes them invaluable pollinators for crops like apples, cherries, and other stone fruits, which are among New York State’s signature agricultural commodities. The close proximity of Cornell Orchards, located just about a third of a mile from East Lawn Cemetery, likely plays a significant role in supporting such a massive bee population by providing an abundant and reliable food source during their critical emergence period. Furthermore, the bees exhibit a preference for sandy soils, which are present in large quantities within the cemetery, providing ideal nesting conditions.
Before this study, surprisingly little scientific information was available on A. regularis. Hoge noted that one of the most detailed references dated back to 1978, underscoring the research team’s opportunity to significantly advance the understanding of this species’ biology and ecological importance. The discovery at East Lawn Cemetery thus not only reveals an astounding aggregation but also provides a crucial living laboratory for studying these poorly understood, yet vital, pollinators.
East Lawn Cemetery: An Unexpected Biodiversity Hotspot
The discovery at East Lawn Cemetery strongly reinforces the emerging understanding that cemeteries, particularly older ones, can function as crucial refuges for biodiversity, especially within increasingly urbanized landscapes. Established in 1878, East Lawn Cemetery has a long history of relatively undisturbed land use. Historical records indicate that Andrena regularis has been present at the site since at least the early 1900s, suggesting a century-long, perhaps even longer, continuous presence of this population.
Scientists explain that cemeteries offer several unique advantages that make them ideal habitats for ground-nesting bees and other wildlife. Firstly, the land is typically peaceful and rarely disturbed by intensive human activity or development. Unlike agricultural fields or residential areas, cemeteries generally maintain stable soil structures and minimal tilling, which is essential for underground nesters. Secondly, and critically for insect populations, cemeteries are often largely free of pesticides and herbicides. The maintenance practices in many older cemeteries prioritize preserving the solemnity and natural beauty of the grounds rather than intensive chemical management. This creates a chemical-free haven in environments where pesticide use is widespread.
Keven Morse, the superintendent of East Lawn Cemetery, whose family has managed the nonprofit cemetery for 46 years, attests to its rich biodiversity. He has observed a wide array of wildlife, including deer, geese, hawks, foxes, coyotes, and, of course, countless bees. Morse recounted his experience, 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." His observations highlight the long-standing presence of these bees and the cemetery’s role as a consistent habitat. The undisturbed nature of the grounds, coupled with specific soil compositions (like sandy soil), creates an almost perfect microhabitat for A. regularis.
This phenomenon is not isolated to East Lawn. Research from other parts of the world has similarly identified cemeteries as significant green infrastructure elements, harboring uncommon plants, insects, birds, and even small mammals, especially in urban settings where natural habitats are fragmented. The East Lawn discovery elevates this concept, demonstrating the potential for cemeteries to host aggregations of pollinators on a scale previously unappreciated, offering invaluable insights into urban conservation strategies and the preservation of ecological services within human-dominated landscapes.
Quantifying the Unseen: The Innovative Research Methodology
Estimating a population of 5.5 million individual bees, primarily nesting underground, required innovative and meticulous research methods. The Cornell team adopted a new monitoring technique utilizing emergence traps. These small, mesh tents, typically covering less than a square meter of ground, are designed to funnel emerging insects into glass jars placed at their apex. This method allows researchers to capture and count a representative sample of insects emerging from the soil within a defined area. As Danforth noted, "You capture a whole community of animals coming out of the ground with this approach."
Between March 30 and May 16, 2023, the research team strategically placed ten such emergence traps throughout the cemetery. Over this period, they collected an astounding 3,251 insects, representing 16 distinct species of bees, beetles, and flies. Crucially, Andrena regularis overwhelmingly dominated these samples, confirming the species’ profound prevalence within the cemetery grounds.
To extrapolate the total population estimate, researchers used the number of bees captured in each trap to calculate the average bee density per square meter across the cemetery’s approximately 6,000 square meters of suitable habitat. Based on these calculations, the estimated total population ranged from about 3 million to 8 million bees, with the most robust average estimate settling at 5.5 million. This statistical approach, grounded in systematic sampling, provides a reliable quantitative measure of the aggregation’s size.
The emergence traps also provided valuable insights into the bees’ emergence patterns, revealing subtle yet significant differences between sexes. Male A. regularis consistently appeared first during warm periods in April, preceding the emergence of females by several days. This protandry, where males emerge before females, is a common reproductive strategy in many insect species. As Hoge explained, "The males come out first and wait for the females, so that they have the best opportunities to mate and pass on their genes." This synchronized emergence ensures that males are ready to mate as soon as females become available, maximizing reproductive success for the species. The detailed data gathered through this methodology offers a deeper understanding of the behavioral ecology of A. regularis, which was previously poorly documented.
Ecological Dynamics: Parasitism and Conservation Concerns
The study at East Lawn Cemetery not only documented the impressive aggregation of Andrena regularis but also shed light on the complex ecological interactions within this bee community. A significant finding was the documentation of brood parasitism by nomad (or "cuckoo") bees, specifically Nomada imbricata. These fascinating, often brightly colored, bees do not construct their own nests or provision their offspring. Instead, they exhibit a kleptoparasitic lifestyle, waiting until A. regularis females have meticulously prepared and provisioned their underground brood cells. Once the host bee has completed her work, the Nomada imbricata female stealthily enters the cell and lays her own egg.
Upon hatching, the nomad larvae exhibit a brutal efficiency, killing the host Andrena regularis larva and then consuming the carefully stored pollen and nectar intended for the mining bee’s offspring. This parasitic relationship represents a natural, albeit challenging, aspect of the ecosystem’s balance. While the presence of parasites indicates a healthy and complex food web, a high incidence of parasitism can exert pressure on host populations, especially when combined with other environmental stressors.
This discovery, while remarkable, comes at a time of increasing global concern over pollinator decline. Habitat loss, pesticide use, climate change, and diseases pose significant threats to bee populations worldwide. Solitary bees, despite their critical ecological role, often receive less attention than social bees like honeybees. The sheer size and historical continuity of the Andrena regularis aggregation at East Lawn Cemetery underscore the urgent need for dedicated conservation efforts for all bee species.
Broader Implications and Conservation Imperatives
The findings from East Lawn Cemetery carry profound implications for pollinator conservation, urban planning, and agricultural sustainability. The discovery serves as a powerful testament to the ecological value of seemingly ordinary urban green spaces and challenges conventional thinking about where significant biodiversity can be found.
For New York State, the identification of such a massive aggregation of A. regularis is particularly significant given the state’s robust apple industry. These early-emerging bees are crucial for the successful pollination of apple orchards, directly contributing to the state’s economy. The research elevates the perceived value of solitary ground-nesting bees, demonstrating their abundance and importance as crop pollinators. Bryan Danforth emphasized this, stating, "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."
The Cornell study provides a compelling case for rethinking land management practices in urban and suburban areas. Local municipalities, urban planners, and cemetery managers now have a clear example of how undisturbed, pesticide-free spaces can become vital sanctuaries for keystone species. Keven Morse’s proactive approach to mowing, mindful of the bee populations, exemplifies the kind of stewardship that can foster coexistence and conservation.
To further locate and protect similar nesting sites, Danforth and his colleagues have launched a global citizen science initiative. This program encourages individuals worldwide to report any ground-nesting bee aggregations they encounter. This collaborative effort aims to harness the power of public observation to map and protect these crucial, often hidden, pollinator strongholds. "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."
Official responses from institutions like Cornell University highlight the pride in their researchers’ contributions to ecological science and their commitment to sustainability. The New York State Department of Agriculture would likely view these findings as crucial for understanding and supporting agricultural productivity, potentially influencing state-level pollinator protection initiatives. Local conservation groups would undoubtedly leverage this discovery to advocate for the preservation of urban green spaces and the adoption of pollinator-friendly landscaping practices.
The collaborative nature of the research, involving postdoctoral researchers Jordan Kueneman and Katherine Odanaka, undergraduate students Steve Hoge ’24 and Cassidy Dobler ’26, and lab technician Rachel Fordyce, underscores the importance of diverse scientific contributions. Funding for this pivotal research was provided by the Cornell Atkinson Center for Sustainability, the National Science Foundation, and the Federal Capacity Funds program, reflecting the broad recognition of its ecological significance.
The remarkable discovery at East Lawn Cemetery serves as a powerful reminder that biodiversity thrives in unexpected places, often hidden in plain sight. It compels a re-evaluation of urban landscapes, transforming cemeteries from mere resting places into dynamic ecosystems vital for the health of our planet and the future of agriculture. Protecting these vast, intricate networks of life is not just a scientific endeavor but a societal imperative.
