Photo Credit: Maria Overlay

The Endangered Rusty Patched Bumblebee


Years ago, buzzing through Indiana ecosystems, the rusty patched bumblebee was once widespread. It pollinated flowers and occupied habitats across the Hoosier state and filled an essential biological niche. But, within the last twenty years, rusty patched bumblebee populations have declined 87%, reaching the point that the IUCN, International Union for Conservation of Nature, has listed the species as critically endangered on their list of threatened species. This threatened bee species is essential to pollinator-plant ecosystems across Indiana’s grasslands and needs human intervention if its population is to rebound.

Threats via Habitat

With its natural range in the North East and Upper Midwest United States, the rusty patched bumble occupies grasslands and tail grass. But, due to habitat loss, most of these habitats have vanished in its natural range. This habitat loss contributes to the species decline, along with intensive farming, disease, pesticide use, and climate change. Prairies and grasslands have been converted to farms or developed areas such as cities, which shrinks the bee’s viable range and pushes the species towards extinction. In addition to habitat loss, pathogen spill-over from commercial bees and the use of pesticides threaten the species. The rusty patched bumblebee can absorb pesticide toxins in their habitats directly through their exoskeleton. The bee’s habitats are being made unlivable not only due to these toxins, but also due to climate change.

Threats via Climate Change

Climate change related factors such as extreme temperature increases, droughts, and late frost events drastically alter ecosystems, leading to more susceptibility to disease, fewer flowering plants, and asynchronicity between when plants flower and when the bees emergence. The major threats to the success and recovery of the species are numerous. Declining and isolated subpopulations of the bee that stem from factors like habitat loss and climate change lead to reduced genetic diversity. Agriculture encroaches onto the bee’s natural habitat and the Nosema bombi ( potentially has caused a sudden decrease in the bee’s population. While the rusty patched bumblebee plays a fundamental role in a healthy ecosystem, it also is vital as a pollinator for commercial products.

Bumblebees as Pollinators

Bumblebees are incredibly important pollinators of agricultural products. This includes crops such as blueberries, cranberries, and clove. And, bumblebees are almost the only insect pollinators of tomatoes. Economically, it has been estimated that native insect pollinators, mostly bees, account for 3 billion dollars of value annually in the United States. Vital to the environment and to important crops, two questions prevail.


What is being done to help the rusty patched bumblebee?

The rusty patched bumblebee is the first bumblebee species to be listed as endangered in the United States. According to Rebecca Riley, an attorney with the DNR, Department of Natural Resources, council, “Federal protections may be the only thing standing between the bumblebee and extinction.” Although, in addition to these protections that are unequivocally helping the species, there are several service programs aiming to assess, protect, and restore pollinators such as bumblebees.

What can you do to help the rusty patched bumblebee?

Above all, the most beneficial action for the rusty patched bumblebee that you can take is to grow native pollinator plants, such as milkweed, in your garden. National Geographic recommends bordering your fruits and vegetables with native flowers. In addition to this, avoid pesticides or other potentially harmful chemicals.

Wrap Up

Climate change and habitat loss challenge the rusty patched bumblebee’s population and recovery. The bee acts as an important pollinator for both commercial crops and wild, naturally occurring plants. Much can be done to counteract the bee’s decline, so join together and support this declining species. Grow native plants, avoid chemicals and support local conservation efforts—consider joining IWF today to support our ongoing pollinator conservation efforts. (