Bombus franklini (Frison)
franklini (Frison, 1921:147 [Bremus]) examined
1 name

TAXONOMIC STATUS: This species has been treated as conspecific with B. occidentalis by Milliron (1971), but has since been shown to be very distinct in morphology by Plowright & Stephen (1980) and Williams (1991 [pdf]), in enzyme mobilities by Scholl, Thorp & Obrecht (1992), and in COI barcodes (Williams et al., 2012 [pdf]).

MORPHOLOGY: photos of male genitalia.

DISTRIBUTION: W Nearctic Region. B. franklini has one of the narrowest distributions of any bumble bee species world-wide. All recent specimens have been collected within a 60 mile (97 km) radius of Grants Pass, Oregon (Thorp, 1970, 2003, 2005; Thorp et al., 1983). This species has shown dramatic declines in its former range and abundance since 1995 (Thorp, 2003, 2005; Thorp & Shepherd, 2005; IUCN, 2008).

IUCN CONSERVATION STATUS: Preliminary assessment as CRITICALLY ENDANGERED (Williams & Osborne, 2009) by criterion A2 (IUCN, 2001, 2008) that it is inferred to have undergone a >80% population reduction since 1995, that the causes may not be reversible and may not yet have ceased, based on few records of individuals in the last four years. There are suggestions that it may be extinct (Buchmann et al., 2008). The last known record is from 2006 (R. Thorp, in litt.).