Prepared by S. Colla and A. Taylor-Pindar

The Rusty-patched Bumble Bee has a distinctive rusty-coloured patch bordered by yellow on the first half of its abdomen and is medium to large in size. Like most bumble bee species the Rusty-patched Bumble Bee has an annual life cycle and a diversity of habitat is required to provide the necessary features/structures for each stage.

The Rusty-patched Bumble Bee was one of the most common species of bumble bee seen in southern Ontario up until the 1980s. Since then the species has exhibited a drastic decline and it is now virtually absent throughout its historical range. The species is currently listed as endangered on the Species at Risk in Ontario (SARO) List under the Endangered Species Act, 2007 (ESA). The only locality within Ontario where the Rusty-patched Bumble Bee has been seen in the last five years is Pinery Provincial Park (Lambton County) despite widespread surveys in Ontario. Historically the Rusty-patched Bumble Bee was common from southern Ontario, east to Quebec, south to Georgia and west to the Dakotas.

There are several threats that may have led to the drastic decline in the species including pathogen spillover, the use of pesticides, habitat fragmentation and habitat loss. Knowledge gaps exist that should be addressed in order to assure the survival of the species. This includes a lack of information on the current population at Pinery Provincial Park and throughout its historic range.

The recovery goal for the Rusty-patched Bumble Bee is to ensure the species' long-term survival in Ontario by restoring and maintaining self-sustaining populations. This will be achieved through protection (and restoration to self- sustaining levels, if required) of the one extant population at Pinery Provincial Park and the establishment of additional populations within the species' historic range in Ontario, if feasible.

The protection and recovery objectives are to:

  • protect, maintain and improve habitat in Pinery Provincial Park where the Rusty-patched Bumble Bee is known to be extant;
  • attempt to establish a captive rearing program (contingent upon the availability and capture of reproductive individuals), if feasible;
  • implement a monitoring program for Pinery Provincial Park and surrounding areas where the Rusty-patched Bumble Bee is known to be extant;
  • survey historically occupied sites and suitable habitat to determine population status and species distribution; and
  • initiate research to address knowledge gaps for the Rusty-patched Bumble Bee.

The area prescribed as habitat in a habitat regulation under the ESA should include the locations where the Rusty-patched Bumble Bee has been collected in the past 15 years: Pinery Provincial Park, the Humber River in Toronto, Manestar Tract in Norfolk County, University of Western Ontario campus, High Park in Toronto, Darlington Provincial Park and Guelph. Within these locations floral diversity is particularly important as it provides resources for foraging. Features used for overwintering, such as abandoned rodent burrows and rotting wood, are also critical to ensure habitat remains suitable within these locations.

It is recommended that if the Rusty-patched Bumble Bee is found at any new locations, the habitat regulation should be updated to include those locations.

If individuals are found at any location it is recommended that habitat be prescribed as a 2 kilometre radius around the area where the individual was seen. A radius of 2 kilometres was chosen as it is known that bumble bee species can forage approximately 1000 to 1750 metres.