Basis for Former Listing

Vertrees's Long-horned Caddisfly (Ceraclea vertreesi) 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 Vertrees's Long-horned Caddisfly 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 the specimens suggests that they may actually be that of a similar and more common species, C. resurgens (Resurgent Long-horned Caddisfly). Thus, special concern status is not necessary until a positive identification can be confirmed. Vertrees's Long-horned Caddisfly was delisted in 2013.

  References and Additional Information

Hilsenhoff, W. L. 1987. An improved biotic index of organic stream pollution. Great Lakes Entomologist 20:31-39.

Houghton, David C. 2012. Biological diversity of the Minnesota caddisflies (Insecta, Trichoptera). ZooKeys 189:1-389.

Houghton, D. C., R. W. Holzenthal, M. P. Monson, and D. B. MacLean. 2001. Updated checklist of the Minnesota caddisflies (Trichoptera) with geographic affinities. Transactions of the American Entomological Society 127(4):495-512.

Minnesota Department of Natural Resources. 2012. Statement of need and reasonableness. Minnesota Department of Natural Resources. Division of Ecological and Water Resources. St. Paul, Minnesota. 337 pp.

Monson, M. P. 1994. The caddisflies (Insecta: Trichoptera) of the Lake Itasca region, Minnesota, and a preliminary assessment of the conservation status of Minnesota Trichoptera. Thesis, University of Minnesota, Saint Paul, Minnesota. 135 pp.

Morse, J. C. 1975. A phylogeny and revision of the caddisfly genus Ceraclea (Trichoptera: Leptoceridae). Contributions of the American Entomological Institute 11:1-97.

Resh, V. H., and J. D. Unzicker. 1975. Water quality biomonitoring and aquatic organisms: the importance of species identification. Journal of the Water Pollution Control Federation 47:9-19.

U.S. Forest Service. 1999. Population viability assessment in forest plan revision. Statement of purpose and reason. Draft species data records: Ceraclea vertreesi (Denning). United States Forest Service, Region 9.

Wiggins, G. B. 1996. Larvae of the North American caddisfly genera (Trichoptera), Second edition. University of Toronto Press, Ontario, Canada. 457 pp.