WOODSTOCK, Ill. (AP) — The sighting of an endangered bee at a college campus in northeastern Illinois has inspired a survey of the flora and fauna in the area.

Loyola University Chicago student Kevin White spotted the rusty patched bumblebee last year at the ecology campus in Woodstock, the Chicago Tribune reported . The bee had a distinctive brown stripe on its back.

“I started taking pictures because the markings on it were so different,” said White, an environmental science major. “Over the next two weeks, we found it four times at the same spot.”

Federal officials declared the species endangered earlier this year, making it the first bee in the continental U.S. to receive that designation. It can be found in the Midwest and Northeast, according to the Fish and Wildlife Service.

The BioBlitz survey documented more than 250 plants, animals and insects on the 98-acre (40-hectare) campus, which features various ecosystems such as savannah, woodlands and wetlands. More than 80 people participated in the Saturday event.

The rusty patched bumblebee wasn’t spotted during the survey. The Rev. Stephen Mitten, the director of research at the ecology campus, said it’s still early for the insects. He also said that they’ll likely reappear on campus this summer.

“Why would it leave? We haven’t done anything to make it go away,” Mitten said.

Researchers are studying what factors may have led to the bees’ decline, said Louise Clemency, field supervisor at the Fish and Wildlife Service’s Illinois office.

“It seems very likely that it’s a combination of stressors that include new diseases from managed and captive bumblebee colonies or potentially new pesticides being used on the landscape, particularly for agriculture,” she said.

Residents should report sightings of the bee to researchers in order to help them identify where to focus conservation efforts, Clemency said.