The first specimen of this species known from North America was collected in 1951, in Placerville, in the west central Sierra Nevada Mountains of California (Strohecker 1955). In 1963, Rentz reported numerous records in the vicinity of the first collection, creating the clump of dots on the above map. The five isolated dots are for records of specimens collected or photographed much more recently: California, 2002; Oregon, 2004, 2009, 2010; Washington, 2010.
In the map above, based on Ron Lyons’ (2012) paper, dots for the extreme north and south of California (Siskiyou and San Diego counties), were added in 2020.
The records for Union County, Oregon and for Santa Clara, San Benito, Monterey, San Louis Obispo, and Santa Barbara counties in California are from research grade records from iNaturalist.
