Using Insects to Track Climate

Three nudes recline, flapping swans and splashing fish behind them shooting powerful jets of water up and over their heads. The iconic Swann Fountain at Logan Square in front of the Academy is a major tourist draw that also reels in a fair amount of locals looking to cool off in the summer heat.

But it’s the steady stream of flying insects that get captured in the fountain’s spray and sucked down into the expansive pool below that commands the attention of entomologist Isabelle Betancourt.

The insects Academy entomologist Isabelle Betancourt collects are being added to the Entomology Collection for a long term study on biodiversity and climate change. Photo and videos by Carolyn Belardo

One recent day she donned knee-high rain boots, grabbed a fine-mesh net, tucked a vial of ethanol into her back pocket, and stepped gingerly into the fountain. Then she waded slowly, methodically in a circle around Alexander Stirling Calder’s sculptures in search of floating insects. And there were a lot of them.

June beetles, scarab beetles, tortoise beetles, ladybugs, dragonflies, fireflies, ants. At the end of her second rotation around the fountain, Betancourt, and Drexel University sophomore Augustus Madden who is interning with her, had collected more than 100 bugs.

These they dropped into a vial with preservatives to take back to the Academy’s Entomology Collection, where they will be sorted, identified, and stored along with the other 3.5 million insect specimens dating back to the institution’s founding in 1812.

This is the third year for the Swann Fountain Insect Survey that Betancourt, a curatorial assistant of entomology, leads and plans to continue indefinitely.

“Insects are intimately intertwined with our environment. They serve important ecological roles, and they are great bioindicators,” Betancourt said. “The presence or absence of certain insect species indicate changes in the surrounding environment.

“The insect samples we collect at Swann Fountain can tell us more about what insects are flying through Philadelphia and how the Philadelphia environment is changing over time. Along with answering the question about what insects are hanging out in Center City Philadelphia, the project will also show when they are here,” she said.

Each insect species has a unique relationship with the environment, and so its presence sends a message.

Comparing the specimens and data year after year can reveal changes in the composition of insect species and give researchers insight into shifts in the climate and the conditions of the surrounding environment. For example, certain insects are more pollution sensitive and others are more pollution tolerant.

“We are learning when to expect certain species to show up in the fountain at a certain time of year. In future samples (whether they are 5, 10, 25, or 50 years from now),  an insect type that doesn’t show up or shows up in unusually high number or at a different time of year will indicate an environmental change that we might want to examine,” Betancourt said.

 

And then there are the surprises.

“Some of the insects in the fountain came from surrounding plants in the park, but others were just passing through,” said Betancourt, who calls herself an urban entomologist. “One year we found a Pine Barrens cicada, but the Pine Barrens is way across the Delaware River in New Jersey. We were also surprised to find a phantom crane fly which is typically found in wetland habitats.”

Mark your calendars: Hundreds of insects that Isa collected in the fountain will be on display at the Academy for Bug Fest, Aug. 12 and 13. To purchase tickets online at a discount, click on the button below.

buy tickets to the Academy of Natural Sciences

If you’d like to connect with Betancourt and learn more about the insect world, tune in to her weekly interactive live insect-themed broadcasts on Periscope every Tuesday at 2 p.m.,  
www.periscope.tv/isabetabug

 

Post by Carolyn Belardo

To read a recent The Philadelphia Inquirer story on the project, visit philly.com.

To see a video report from CBS Philly, visit cbsphilly.com.