The Rusty-patched Bumblebee (Bombue affinis) has the dubious distinction of being the first bee to be listed as federally endangered. This formerly common bee species went into rapid and steep decline in the mid 1990s into the 2000s for reasons that are not entirely clear. Many historic sites that were traditionally occupied yearly failed to yield any bees despite intensive, targeted searches by experts. Theories for the decline include the introduction of a pathogen from managed colonies of commercial bumblebees used for crop pollination, habitat fragmentation, or pesticide use (Williams et al. 2014).
There are 15 records in the project database.