Leaves aren’t the only things hanging from the trees in downtown Toledo these days.
Blue pouches, called “water pillows,” are clipped to the branches of trees on Jackson Street and in Civic Center Mall, attracting a swarm of insects that are the subject of a Bowling Green State University lab research project examining water stress among arthropods, or the extent to which bugs such as crickets might be eating leaves for hydration.
Building on prior research, Kevin McCluney, an assistant professor in BGSU’s biology department, and a group of students have been spending afternoons and evenings at three spots in northwest Ohio, counting bugs in part to determine what conditions prompt arthropods — invertebrate animals with an exoskeleton, segmented bodies, and jointed appendages — to eat more leaves than they might otherwise because they need water.
“Throughout the eastern U.S., there has been increasing [pest] damage to urban landscaping trees,” Mr. McCluney said. “That has been causing some pretty serious problems because these trees provide a lot of services to humans ... and they cost cities a lot of money to deal with dead or dying trees. And so there has become this really big question: Why is that happening?”
Researching in Raleigh, N.C., last summer, Mr. McCluney and a colleague found that when arthropods were wanting for water — or “water stressed” — more damage was found on leaves of the area’s landscaping maple trees. Now, through the Ohio project that began in early June and is to run through August, Mr. McCluney wants to find out whether the same water demand exists in a large city like Toledo, a small city like Bowling Green, and sand dunes like Oak Openings. Urban areas in the eastern United States generally are hotter and drier than the regions around them, Mr. McCluney said.
Arthropods suck water out of the water pillows, so every few days, researchers from Mr. McCluney’s lab go into the field, place water pillows — some with water, some not — on and around trees, and later count how many critters have stuck to them. They also take measurements, including the surrounding area’s temperature, humidity, and soil moisture.
Late Tuesday afternoon, Mr. McCluney and Nadya Mirochnitchenko, a BGSU student and research assistant, set out amid strong winds to count arthropods on the water pillows they had clipped to branches and put on the ground beneath them an hour earlier. Some arthropods spend their lives on the ground and others in trees, Mr. McCluney said. A few minutes into culling the data, Ms. Mirochnitchenko, 20, saw an ant on a wet water pillow, consuming water.
The goal, Mr. McCluney said, is to develop relationships that might exist between certain conditions and increased water demand from arthropods. He said he looks at the Ohio research as “pilot data.” If this effort yield good results, further research will be needed, he said.