A study at the Rio Botanical Garden shows the importance of urban green spaces for the conservation of stingless bees

One study published this month in the scientific journal “Rodriguesia” highlights the essential role of stingless bees in pollination, particularly in the Atlantic Forest. The research also indicates that urban green spaces serve as refuges for the nests of these species during the breeding season, given the increasing loss of natural habitats.

Titled “Diversity and nesting characteristics of stingless bees in an urban green area, the Botanical Garden of Rio de Janeiro,” the study, conducted by agronomist Maria Lucia França Teixeira, identified a significant diversity of stingless bees in the Rio de Janeiro Botanical Garden—an important green space within the urban context—and studied their nests.

So-called stingless bees because they have atrophied stingers, these bees pose no risk to the population and are essential for the survival of a large portion of native plants, ranging from low-growing species to large trees. If they become extinct, the reproduction of wild plants will be compromised.

Over the course of eight years of monitoring at the Rio Botanical Garden arboretum, 94 nests belonging to 13 species were recorded, with Tetragonisca angustula standing out as the most abundant. Most of the nests were found in trees, but the researcher also observed bees occupying walls, monuments, and even the ground—an indication of these species’ ability to adapt to the urban environment.

Maria Lucia França Teixeira, who is responsible for the institution's meliponary, points out that urbanization has reduced native vegetation and natural habitats, leading stingless bees to migrate to urban areas, where they find potential nesting sites—a process involving the selection, construction, and occupation of nests—such as large trees — often hollow and old — and artificial substrates, including stone walls.

“In this context, the study aimed to analyze the diversity and nesting characteristics of stingless bees in the arboretum, identifying factors that influence the establishment and maintenance of their nests in an urban environment,” says the agricultural engineer.

According to the article, stingless bees account for about 70% of foraging bees—those that leave the nest in search of resources such as nectar and pollen—in the tropical forests of the Atlantic Forest. Brazil is home to 244 described species of stingless bees and about 89 species that have not yet been described. In the state of Rio de Janeiro, 22 species have already been recorded, although studies on stingless bees in urban areas are still scarce.

The study’s findings highlight the importance of conserving stingless bee nests in urban green spaces. The diversity and abundance of pollinators are linked to connectivity between green areas. The Botanical Garden’s arboretum is connected to fragments of Atlantic Forest and other green areas, such as Tijuca National Park, serving as an ecological corridor and urban refuge for pollinators.

- Despite the environmental pressures typical of urban settings, such as human presence and land management, the diversity of stingless bees in the Botanical Garden’s arboretum remains high, functioning as an ecological corridor within the city – emphasizes Maria Lúcia.

According to the researcher, this scenario is the result of a combination of resource availability, the preservation of old trees, and ecological connectivity.

- The creation, maintenance, and expansion of ecological corridors are fundamental strategies for preventing the extinction of native pollinators, including stingless bees. These actions are reinforced by initiatives such as environmental education, public policies, and research focused on the conservation of these species,” she concludes.

The article is available at https://www.scielo.br/j/rod/a/Mn36zhy96hpp8NGCKfXrWmL/?lang=en