Bee research progresses, new questions emerge

With boxes of bees in hand, Paige Hickman, ’17, paid a second visit to Sam Droege, wildlife biologist, at the USGS Bee Identification and Monitoring Lab in Beltsville, Maryland as part of research they began at Allegheny College over the summer.

There, Hickman, along with Erica Moretti, ’17, spent over nine hours sorting through and organizing close to a thousand specimens of wild bees—meaning, all bees excluding honey bees, which are domesticated—collected between July and September 2016.

Last time Hickman visited the Beltsville lab, her samples turned up one insect that did not fit into any known species and has since been under investigation as to whether it might represent an entirely new species of bee.

This time around, the team did not encounter any new unknown samples. But they did find a new surprise.

Out of the 96 species of bees represented by the hundreds of samples they examined, the team found a specimen of Hylaeus pictipes, a species that had not yet been sampled in the continental United States, making it technically invasive.

“It took Sam [Droege] a little while, because we didn’t know it was here [in Pennsylvania],” said Beth Choate, associate professor of environmental science at Allegheny. “I know they have found some in Canada before—Ontario, I believe. When Sam isn’t quite sure what something is, he takes pictures and sends them out to the few folks who are out collecting and identifying these bees.”

H. pictipes had formerly been sampled in Mississauga, Ontario by Jason Gibbs, research associate at Michigan State University, according to Choate. Hickman said that the species is native to Europe, but that it could have come to the western hemisphere by the transportation of crops produced in Europe.

Droege developed the key found on that Hickman and Moretti have been using in their research for identifying bees down to the genus and species level.

“He goes through them pretty quickly, and then takes some time with the ones that are more challenging and take more digging around to find out,” Moretti said. “Now we’re essentially sitting on a pile of data.”

Even with his experience in the field, Droege occasionally comes across specimens that need to be sent out to more specialized labs. The group came across specimens that fell under the genus Sphecodes, which Droege could not identify down to the species level on his own.

“There are labs dedicated to certain genera of bees that are trying to re-evaluate what should be a species and what shouldn’t,” Hickman said. “So [Droege] took one of our Sphecodes samples to send to one of those labs.”

Droege will use the sampling data to update his key and his website, according to Hickman and Choate. The latter includes information like species range and recorded appearances, all of which have a relevant role in pollinator research.

Hickman and Moretti’s research fits into a national trend within the academic community of cataloguing local native pollinators. Once Droege sends Hickman and Moretti a final copy of all the species they uncovered, the team will have a reference guide—as well as a physical collection of specimens—for what can be found in the way of bees in the Meadville area.

In a 2010 report, published by the Journal of the Kansas Entomological Society, titled, “A Checklist of the Bees (Hymenoptera: Apoidea) of Pennsylvania,” over 370 species of bees have been reported in the state of Pennsylvania. At the time of the report’s writing, 150 of these had not yet been found in the state.

Scientists are now more interested than ever in native bee populations because of native bees’ intricate—and often unknown—relationship with honey bees, whose populations are in global decline, according to the report. For example, in one citation within the report, the presence of native bees caused a fivefold increase in honey bee efficiency on sunflowers.

The work done by Hickman and Moretti branches from a preliminary investigation done by Hillary Krill, ’15, in summer 2014. Interested in local pollinators, Krill used a method for trapping bees from one of Droege’s papers in order to survey the local populations of wild bees around Allegheny’s campus.

Moretti, then a rising sophomore, helped Krill trap bees. The following summer, Moretti used the skills she had developed and the methods they had perfected to expand the survey to downtown Meadville and north of campus, around the RobertsonAthletic Complex. One summer later, Kaye Moyer, ’19, joined the team.

“Usually with entomological papers, if you want to publish, you need two seasons of sampling,” Moretti said. “Paige [Hickman] stayed on last summer with [Moyer].”

The two summers’ worth of sampling resulted in a large reference collection, and the information coming out of Droege’s lab could help students at Allegheny take the reins of future studies on pollinators.

“We’ve got a great diversity study in urban environments and the resources they provide,” Choate said. “The big interest is, can we look at agricultural fields, and what are we finding in those?”

Meet the women behind the buzz who made bee research possible

Paige Hickman

For Hickman, an environmental science and Spanish double major, the bee species data gathered in Beltsville will help advance her senior comprehensive project to its next phase. Hickman is interested in looking at the relationship between wild bees and local plants—specifically, how the diversity of one might affect the diversity of the other.

Native bees, like any organism, coevolve with living things in the world around them. Because pollination is essentially a symbiotic relationship between bee and plant, native bees tend to be strongly associated with the plants they pollinate.

Hickman is examining if diversity in native bees changes in areas with more or less local plants. Urban areas tend to have more ornamental plants, or those bred for decoration, which have not coevolved with local pollinators. Because the two have no evolutionary history together, native bees often cannot access the pollen of ornamental plants.

From their sampling, the team will know how many bees and how many bee species visited each sampling site over the course of the two summers. It could then be determined how bee diversity and numbers change from Robertson to Allegheny to downtown Meadville.

Erica Moretti

Instead of plant diversity, Moretti is interested in burrowing surfaces, which can be pervious or impervious, or easy or difficult to burrow into, respectively. Pervious surfaces are things that bees naturally nest in, such as soil, trees or grassy areas. Impervious surfaces are things one would find in an urban setting: concrete, brick or soil that has been compacted by traffic or development.

Moretti plans on using Allegheny’s geographic information system lab in Carr Hall to map out sampling sites. Once the bee collection data is in, she will have a complete picture of how bees are distributed along a gradient of pervious and impervious areas, including raw numbers of bees and species diversity.

“The first round of analysis is: do we see a change in the total number of bees from areas with more pervious surfaces to areas with less pervious surfaces?” Moretti said. “Then, specifically, I’ll be looking at each of these species and classifying them based on how the bees nest.”

Moretti hypothesizes that she will find less soil nesters in the downtown Meadville sampling sites. These findings would be consistent with the larger observed trend in the scientific community.

Beth Choate

Choate’s research prior to coming to Allegheny involved predatory ants in lowbush blueberries.

Often the predators of pests, ants in those field systems were something of a cosmopolitan predator; no one had looked at exactly what they were eating until Choate became interested in them. Her work began with figuring out whether they were causing an economic loss based on their dietary habits.

For her postdoctoral research, Choate expanded her repertoire to look at the suite of predatory insects that were involved in wheat ecosystems.

“I went from focusing on one thing to what’s in the soil, what’s on the plants [to] what’s on the soil surface crawling around,” Choate said.

After coming to Allegheny, Choate examined soil insects living in the Bousson reserve. Choate would like to see the sampling projects that she and her students have undertaken expand into areas related to agricultural fields.

“We’ve got a great diversity study in urban environments and the resources they provide,” Choate said. “The big interest is, can we look at agricultural fields, and what are we finding in those?”