Basis for Former Listing
Vertrees's ceraclean caddisfly is known in Minnesota from 39 specimens. These have all been collected from localities within a 40 km (25 mi.) radius in and around Itasca State Park. These occurrences are widely disjunct from the other known populations in western North America where the species is also uncommon. Further inventory work is needed to delineate the range of this caddisfly. Vertrees's ceraclean caddisfly was listed as a special concern species in Minnesota in 1996.
Basis for Delisting
The Minnesota specimens of C. vertreesi were collected in habitats considered atypical for this species, and are separated from other known populations by more than 1000 km (620 mi.). Recent examination of C. vertreesi specimens suggests that they may actually be that of a similar and more common species, C. resurgens. Thus, special concern status is not necessary until a positive identification can be confirmed. Ceraclea vertreesi was delisted in 2013.