Rusty Patched Bumble Bee

the first bumble bee species listed under the Endangered Species act

A hiker along the Appalachian Trail could see up to 18 different species of bumble bees from Georgia to Maine, oftentimes seen buzzing from flower to flower in spring through late summer. Bumble bees, although small in size and rarely seen for more than a few seconds, are yet another integral piece to the A.T. experience that often go unnoticed. These keystone species in the genus Bombus are some of the most effective pollinators among the entire suite of pollinating insects on the Trail. Hikers who stumble across a ripe blueberry or blackberry along the Trail may have the pollinating bumble bees to thank. Bumble bees also pollinate many important food crops such as tomatoes, peppers, raspberries, blueberries, chives, cucumbers, apples, strawberries, alfalfa, and more. To put these pollination services into perspective, the total economic output of all pollinators in the U.S. is estimated at three billion dollars.

One species of bumble bee that historically spanned the entire A.T. landscape is the rusty patched bumble bee (RPBB). The RPBB is rather large compared to other species in the genus. The workers and males have a distinct rusty patch (hence the name) on the top of their abdomen. Unfortunately, the beautiful sounds of RPBB’s bustling about has been silenced over the last three decades leading to the RPBB being the first bumble bee species listed under the Endangered Species Act. The RPBB’s entire population has dropped by 87 percent since the 1990s, with the only current recorded (2007-2020) population near the A.T. occurring within Sky Meadows State Park near Front Royal, Virginia. There are many variables that scientists attribute to this decline, including an introduction of deadly pathogens from European bees, the increased use of pesticides like neonicitinoides, climate change, small population dynamics, and habitat loss and degradation. Ill-timed or excessive mowing/tilling/grazing, monoculture farms, reforestation, invasion from non-native plants, and development are all forms of habitat loss and degradation. RPBB’s are also ground nesters so soil disturbance has the potential of destroying a colony and/or a colony’s queen.

Only five counties in the state have current RPBB occurrences, one of which is found along the A.T. in Sky Meadows State Park while all other occurrences are found west of the Trail in Central Virginia. The latest discovery of the RPBB in Bath County, Virginia, along an old Forest Service road pollinating Rhododendron at a higher elevation than is typical, has shed new light and a sense of optimism for this species known habitat requirements. Prior to this discovery, RPBB’s were mostly expected to be found in lowland open fields with a wide array of flowering plants. With a decline in healthy early-successional habitats across eastern U.S. forests, it was thought that the RPBB’s fate was rather grim. Now that habitat requirements have potentially expanded, RPBB could be found in many small canopy openings or even along many portions of the A.T. This discovery also provides further recognition that the over 5,000 acres of early-successional habitat that the Appalachian Trail Conservancy (ATC) cooperatively manages is increasingly important and has the potential to harbor additional RPBB populations.

This exciting news still comes with the realization that a lot of work must be done. Fortunately, the U.S. Fish and Wildlife Service developed and released a draft recovery plan in September of 2019, which land managers along the A.T. will utilize in high priority locations. One way hikers and volunteers can help is by participating in a new citizen science effort led by the Xerces Society called Bumble Bee Watch in which citizens all over the country can survey and inventory bumble bee species with no previous entomological experience required. As the recovery effort for this species continues, ATC staff alongside our partners will continue to search for this elusive bumble bee while also providing suitable habitat in high priority areas along the Trail.

The RPBB is a seemingly small part of the A.T. visitor experience, but one that could disappear from the Appalachian Trail completely. This steep decline is not an unfamiliar story for many pollinators across the United States and more specifically for a lot of endemic species across the Appalachian Trail landscape.

But what is the value of these declining species to the Trail experience? The value of the A.T. is most often represented as a human resource for recreation, recuperation, and in Benton MacKaye’s words “a refuge from the scramble of everyday worldly commercial life.” What is commonly overlooked is the fact that the health, value, and uniqueness of this refuge is inextricably linked to the health and intrinsic value of endemic species within the Appalachian forest ecosystem. Only through increased conservation and cooperative management efforts can this refuge continue to be protected and it can start with something as small as the rusty patched bumble bee.

For more information about bumble bees visit: xerces.org/bumblebees