What began as a cost-saving commute for a Cornell University entomology lab employee has blossomed into a groundbreaking scientific discovery, revealing East Lawn Cemetery in Ithaca, New York, as a sanctuary for an astonishingly vast population of wild bees. Rachel Fordyce, an employee in Cornell’s College of Agriculture and Life Sciences, noticed an unusual abundance of bees while walking through the cemetery in the spring of 2022 as a shortcut to her workplace. Her keen observation, a simple act of noticing the natural world around her, led researchers to identify one of the largest and oldest known aggregations of ground-nesting bees ever documented.
The insects, identified as Andrena regularis, commonly known as the "regular mining bee," are solitary wild bees that excavate nests underground. These unassuming insects play a critical role in pollination, benefiting both agricultural crops and wild plant species. The scale of the aggregation found at East Lawn Cemetery has astounded scientists, with estimates suggesting the 1.5-acre site is home to approximately 5.5 million individual bees. This concentration is reportedly more than 200 times the number of bees found in typical honeybee hives and surpasses the human population density of Manhattan threefold.
Steve Hoge ’24, the lead author of the study published on April 13 in the journal Apidologie, expressed his surprise at the magnitude of the discovery. "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. He conducted this significant research as an undergraduate researcher in the lab of Professor Bryan Danforth, a prominent entomologist at Cornell.
Unveiling a Bee Haven: The Cemetery’s Enduring Appeal
The research undertaken by the Cornell team delved into the biology of these often-overlooked wild bees, simultaneously underscoring their vital importance as pollinators for economically significant crops. Apples, a signature commodity of New York State, stand to benefit considerably from the presence of Andrena regularis.
Professor Danforth emphasized the broader implications of the findings. "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," he explained. The historical presence of A. regularis at East Lawn Cemetery dates back to at least the early 1900s, with the cemetery itself established in 1878. This long-standing coexistence highlights the cemetery’s consistent suitability as a habitat.
The discovery reinforces the growing understanding that cemeteries can serve as crucial refuges for biodiversity. Older cemeteries, particularly those situated in urban environments, have a documented history of providing sanctuary for a variety of flora and fauna, including rare plants, diverse insect populations, and various bird and mammal species.
Keven Morse, superintendent of East Lawn Cemetery, has witnessed this rich biodiversity firsthand during his family’s 46 years managing the nonprofit institution. He has observed a wide array of wildlife, including deer, geese, hawks, foxes, and coyotes, in addition to the abundant bee populations. Morse noted that the bees have never posed a threat to him, even when he had to navigate around areas with particularly heavy bee activity. "I just felt bad having to mow in certain areas," Morse recalled. "There’s probably three or four sections where they really migrate heavy, there’s a lot of them."
The researchers attribute the cemetery’s success as a bee habitat to several key factors. The environment is inherently peaceful and rarely subjected to disruptive human activities. Crucially, these areas are typically free from the widespread use of pesticides, which can be detrimental to pollinator populations. This undisturbed, low-intervention setting creates an ideal environment for ground-nesting bees to thrive.
The Dominance of Solitary Ground Nesters
While honeybees often capture public attention, the scientific community increasingly recognizes the significance of other bee species. Approximately 75% of all bee species are solitary ground nesters, mirroring the lifestyle of Andrena regularis. "It’s the most common lifestyle for bees," Professor Danforth confirmed, highlighting the widespread nature of this nesting behavior.
When Hoge embarked on his research into A. regularis, he discovered a surprising paucity of scientific literature. One of the most detailed references he could find dated back to 1978, presenting an opportunity for his team to significantly contribute to the understanding of this species’ biology.
The life cycle of the female A. regularis involves constructing intricate underground nests. Within these subterranean chambers, she meticulously deposits eggs, provisioning each with a mixture of pollen and nectar. The developing larvae mature beneath the surface, eventually emerging as adult bees. A unique aspect of this species’ biology, as Hoge pointed out, is its overwintering as adults. This allows them to emerge exceptionally early in the spring, a timing that often coincides with the blooming of crucial early-season plants like apple trees.
"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. Their foraging activities also extend to fruit trees and wildflowers that bloom in the early spring. In New York, their emergence typically occurs in April, coinciding with sustained daytime temperatures around 70 degrees Fahrenheit. The proximity of Cornell Orchards, located about a third of a mile from the cemetery, likely plays a supportive role by providing a continuous source of nectar and pollen during the critical spring blooming period. Furthermore, the cemetery’s soil composition, which is rich in sand, is particularly favored by A. regularis for nest construction.
Quantifying a Million-Strong Community: Innovative Counting Methods
To accurately estimate the bee population and meticulously document their emergence patterns, the research team employed an innovative monitoring technique. They utilized emergence traps, which are small, permeable mesh structures designed to cover less than a square meter of ground. These traps effectively capture insects as they emerge from their subterranean nests, funneling them into collection jars.
"You capture a whole community of animals coming out of the ground with this approach," Professor Danforth described, emphasizing the comprehensive nature of the method. Between March 30 and May 16 of 2023, the research team strategically deployed 10 of these traps across various locations within the cemetery.
The traps yielded a remarkable collection of 3,251 insects, representing 16 different species of bees, beetles, and flies. The overwhelming majority of these captured specimens were Andrena regularis. By analyzing the number of bees collected in each trap and considering the total area of the cemetery, which is approximately 6,000 square meters, the researchers were able to calculate an average bee density. This data allowed them to estimate the total bee population within the cemetery, arriving at a range of approximately 3 million to 8 million individuals, with a mean estimate of 5.5 million.
The emergence traps also provided valuable insights into the timing of male and female emergence. Male bees, Hoge observed, were the first to appear, emerging during warmer periods in April. Females typically followed several days later. This staggered emergence is a crucial reproductive strategy. "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. This ensures that mating opportunities are maximized as soon as females are ready to reproduce.
Threats to an Ancient Ecosystem: Parasites and Conservation Imperatives
Beyond cataloging the sheer numbers, the study also shed light on the ecological interactions within the cemetery’s bee community. Researchers documented instances of brood parasitism by nomad bees, specifically Nomada imbricata, also known as "cuckoo" bees. These parasitic bees exhibit a unique predatory behavior: they patiently wait for A. regularis females to construct and provision their brood cells before surreptitiously laying their own eggs within them.
Upon hatching, the nomad larvae are programmed to eliminate the host bee larvae and consume the stored pollen and nectar. This parasitic relationship highlights the delicate balance of the ecosystem and the vulnerabilities faced by the mining bee population.
Recognizing the critical importance of these nesting sites and the potential threats they face, Professor 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. The goal is to create a comprehensive database that can aid in identifying and protecting similar habitats worldwide.
"These populations are huge, and they need protection," Professor Danforth urged, emphasizing the urgency of conservation efforts. "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 underscores the need for greater awareness and proactive conservation strategies.
The study’s collaborative nature is evident in its list of co-authors, which includes 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 this remarkable investigation. Funding for this significant research was generously provided by the Cornell Atkinson Center for Sustainability, the National Science Foundation, and the Federal Capacity Funds program, demonstrating a collective commitment to understanding and protecting vital pollinator populations. The discovery at East Lawn Cemetery serves as a powerful reminder of the biodiversity that can exist in unexpected places and the critical role that citizen science and dedicated research play in its preservation.
