Doing good for bumble bees takes finding out what’s bad for them.
Sarah Scott, a CFAES entomology doctoral student, is studying how the fuzzy, buzzy, black-and-yellow pollinators get exposed to heavy metals in their environment—and what it can mean to their survival.
Scott, at CFAES’ Waterman Agricultural and Natural Resources Laboratory, poses near hives housing bumble bees’ domesticated cousins. (Photo: Ken Chamberlain, CFAES.)
Tackling causes of pollinator decline
Supported by a highly competitive National Science Foundation graduate research fellowship, Scott hopes to contribute to what’s known about pollinator decline: the mysterious drop-off in bumble bees, honey bees, and other insect pollinators around the world, including in the United States and in Ohio.
Scott’s goal, she says, is to “really understand how human factors affect pollinators, and where to best add habitat for them.” Her advisor is CFAES entomology professor Mary Gardiner.
Wild bumble bees, like honey bees, collect pollen from flowers and live in colonies.
Heavy metals, which are toxicants, come from both natural and human sources, including factory emissions, vehicle exhaust, and dust from old lead paint. Sometimes, in urban areas, they can get in the soil, where plants may take them up. Do foraging pollinators take them up, too?
Research based at Waterman farm
To find out, Scott keeps several hundred bumble bees inside each of 12 room-sized tents at CFAES’ Waterman Agricultural and Natural Resources Laboratory, located at Ohio State’s Columbus campus.
She feeds her subjects pollen and sugar water containing realistic, real-world concentrations of one or a combination of four heavy metals: cadmium, chromium, arsenic, and lead.
Eventually, she collects the bees, measures the heavy metals in their bodies, and counts the numbers of pupae, larvae, and adults—signs of the colony’s health, or lack of it.
For now, Scott isn’t certain how wild bumble bees get exposed to heavy metals. It could be from pollen, water, or dust. One possibility: the bees’ hairy bodies, which carry a slight electrical charge, might serve as “flying Swiffers,” she says.
Pollinators key for crops
Pollinator decline, whose possible causes also include pesticides and parasites, is a problem for more than pollinators. Food crops that need insect pollination—about a third of the crops grown around the world, including in America—are at risk, too.
Scott, whose first field research experience (as a Michigan State University undergraduate) involved elephants and other large mammals in Uganda, said she’s happy to be working with their tiny friends now. She says she hopes her findings get put to use in creating new, healthy habitat for them.
“The strength of science is how far its impact goes,” Scott says. “What’s the point of learning something if it’s just going to sit on a bookshelf?”