Don’t let them Bee misunderstood

Proving the benefits of native bee with a bad reputation

Todd McLeish

Carpenter bees are among the largest bees in the Northeast, and since they burrow into wood – including houses – they have a bad reputation.

But University of Rhode Island junior Becky Gumbrewicz is hoping to change that reputation and demonstrate that the insects provide significant benefits to people, too.

The bees are important pollinators, but because they are so large they sometimes cannot get their head far enough into some flowers to collect nectar. 

So in a strategy called nectar robbery, they instead slit the side of the flowers to feed on the nectar without pollinating the flowers.

Gumbrewicz joined with graduate student Sara Tucker and URI Professor Steven Alm to see if the strategy had any negative implications for local blueberry crops.

“We know that carpenter bees are managed similarly to honey bees in Brazil and the West Indies to pollinate passion fruit, and in other parts of the world to pollinate eggplant, tomatoes and other vegetables and many types of flowers,” Gumbrewicz said. 

“We were looking to see if they are also beneficial to blueberry growers. If so, small farmers could use this native species for pollination rather than bringing in expensive honey bee hives.”

The research team collected 33,000 flowers that had fallen from blueberry bushes and conducted a wide variety of measurements to determine whether there was a correlation between flower size and whether the bees used the nectar robbery strategy.

“Nectar is the food source the bees are trying to get at while they’re simultaneously pollinating the flower,” explained Gumbrewicz, an environmental science major from Oxford, Conn. 

“But blueberry flowers are really tiny and sometimes pretty narrow. When a bee goes to a flower, the hope is that it gets pollen on itself and flies to another flower to pollinate. But because of the size of the carpenter bees, they sometimes use their maxillae to pierce the side of the flower to draw out the nectar with their tongue.”

She found that about 34 percent of the blueberry flowers she collected had slits in their side indicating a bee had robbed the flower of its nectar.

“But when we looked at the weight of the berries that developed from slit flowers and measured their sugar content, we found that there wasn’t a significant difference from fruit which developed from unslit flowers,” she said. “The slitting didn’t seem to have a detrimental effect on fruit yield. So the bees don’t harm the harvest and they do benefit the pollination.”

While Gumbrewicz said she is happy with her results and is pleased to confirm the beneficial role the bees play, she is also pleased with her first hands-on environmental research project.

“It was nice to get out in the field every day and earn this experience with some incredible people, and to study something that’s really important,” she said. “Bees are so important to our food and pollination services, so I really enjoyed working on a project that mattered and that, hopefully, a lot of people will see value in and will care about, too.”

Her research was supported by the URI Coastal Fellows program, a unique initiative designed to involve undergraduate students in addressing current environmental problems. Now in its 21st year, it is based at URI’s College of the Environment and Life Sciences. Students are paired with a mentor and research staff to help them gain skills relevant to their academic major and future occupations.

“I also love communicating my research to people,” added Gumbrewicz, who will present the results of her research to the URI community in December. She will also accompany Tucker to the annual meeting of the Entomological Society of America in Denver in November, where Tucker will present some of their research results. 

“I enjoyed explaining what I was doing and why it’s important, which validated some of the plans I have for my future. It was a great learning experience and a very gratifying experience overall.”

With two years to go before earning her undergraduate degree from URI, Gumbrewicz is beginning to formulate a plan for her future. She sees herself working in an entomology laboratory continuing her research on bees and other insects, or perhaps working in the fields of restoration ecology or environmental chemistry. 

She is planning on enrolling in graduate school, and perhaps even joining the Peace Corps afterwards to fulfill her dream of traveling the world to help those in need.

“I really just want to be able to conduct my own research one day and communicate the importance of it to the public. I want to raise awareness about the work I’m doing and why it all matters,” she said.