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Rusty Patched Bumble Bees Spotted

August 7, 2023 11:59 AM
© © Steve Barten

A federally endangered rusty patched bumble (Bombus affinis) bee was discovered at a Lake County forest preserve last week. This was the first recorded sighting of the rare species at this preserve and joins a handful of other recent bumble bee detections.

The rusty patched bumble bee population has declined by 87% over the past 20 years, according to the U.S. Fish and Wildlife Service. It's one of 10 bumble bee species in Illinois and, in 2017, became the first pollinator protected under the federal Endangered Species Act. Habitat loss, pesticide use, climate change, intensive farming and possibly disease are factors for the decrease in numbers.

Dan Sandacz, restoration ecologist at the Lake County Forest Preserves, was monitoring interactions between plants and pollinators. He observed and recorded all types of insect pollinators, including bees, moths, butterflies and beetles.

“I had a stroke of luck and detected the federally endangered rusty patched bumble bee,” he said. “I observed it pollinating bee balm or wild bergamot (Monarda fistulosa).”

Bumble bees are a keystone species in high quality ecosystems. Their work is necessary for wildflowers to reproduce and to create seeds and fruits that feed wildlife and humans, experts say.

Over the past few months, the rusty patched bumble bee has been spotted four other forest preserves in the county.

Healthy woodlands, grasslands and tallgrass prairies are essential to the rusty patched bumble bee's survival. “The work we do across the forest preserves to restore and maintain healthy, diverse landscapes helps bee species thrive,” said Natural Resources Director Pati Vitt.

The species have entirely black heads, but only workers and males have a rusty reddish patch centrally located on their back.

“I was over the moon excited when I spotted the bee!” Sandacz said. “Steve Barten, the volunteer I was working with, captured pictures. It's rewarding to see first-hand the results of the Forest Preserves restoration and management efforts, which created critical habitat for this endangered species."

Educating the public about the vast conservation effort to save the bees is also part of the Forest Preserves plan. The rusty patched bumble bee is one of the last bee species to go into hibernation. Queens are the first to emerge in early spring. Their long colony life stretches from April through September requiring a constant supply of nectar and pollen from a diversity of native flowers.

“Restoring land provides a place for native plants and wildlife,” Vitt said. “It also increases biodiversity and makes our landscapes sustainable for future generations.”