SOUTH KINGSTOWN, R.I. (WPRI) — While the results of a two-year study on bumblebees in Rhode Island concluded that one species was still around despite not being spotted in more than a decade, it also confirmed that four others have all but vanished from the state.
Elizabeth Varkonyi, a University of Rhode Island (URI) graduate student, worked alongside Professor Steven Alm to conduct a bumblebee survey across the entire state.
“There had never been a bumblebee survey of Rhode Island – or a statewide survey of any kind of bee – and there are some species in the URI historical insect collection that are no longer found in the state,” Varkonyi said.
Varkonyi said there used to be 11 species of bumblebee in Rhode Island, but only six of them have been spotted since 2014.
“I wanted to get a better idea of if those six were truly the only species found here,” she said.
Since 2019, Varkonyi, Alm and two other graduate students have captured bumblebees at 54 sites across the state, while also surveying an additional 48 sites with abundant flowers to see which species the bees were pollinating.
Varkonyi’s bumblee survey ended earlier this year, and of the more than 7,000 bees she documented, 82% were one of two species – the common eastern bumblebee or brown belted bumblebee.
The eastern bumblebee, she said, appears to be the most dominant across the state.
“That could be a factor contributing to our bumblebee decline, competition with this species,” she explained. “A lot of farmers purchase colonies of this species to pollinate their crops, and they might carry parasites or diseases that could be spread to wild populations of other species.”
The most notable finding, according to Varknoyi, was a single American bumblebee back in August. Until this year, the species hadn’t been spotted in Rhode Island in more than a decade.
“We were really only expecting to find the six species that we knew were here, so we couldn’t believe it when we found that seventh species,” she said.
Throughout the survey, Varkonyi also found 23 yellow bumblebees, which is another rare and declining species in Rhode Island. Three other bumblebee species were spotted during the survey, including the two-spotted bumblebee, half-back bumblebee and confusing bumblebee.
As expected, Varkonyi didn’t record any of the four remaining bumblebee species listed in the URI historical insect collection. She said while some of the species are still found in nearby states, the populations of each appear to be declining.
Varkonyi believes these species may be migrating northward due to climate change. She said this is concerning because the survey also concluded that the bee species all have their preferences when choosing which plants and flowers to pollinate.
“Having a higher diversity of bumblebee species is important because we found that each species has its own floral preferences,” Varkonyi explained. “Losing one species can negatively affect the flowers and crops it pollinates.”
The majority of the bumblebees surveyed over the last two years were found on a variety of plants, including bee balm, common St. John’s wort, yellow wild indigo and red clover.
Varkonyi was recently recognized for her work nationally at the annual meeting of the Entomological Society of America in Denver earlier this month, where her research poster won first place in the Systematics, Evolution and Biodiversity category.
While the recognition came as a surprise, Varkonyi said she’s really excited others are appreciating her findings.
“It’s good to see and it gives me a good feeling that people care about conserving bumblebees,” Varkonyi said.