Hydroptila novicola Blickle and W.J. Morse, 1954
Basis for Former Listing
Hydroptila novicola is known in Minnesota from approximately 30 localities in the northeastern portion of the state, most recently in 2001. These occurrences are disjunct from the other known populations of this species in the northeastern and southeastern United States. Further inventory work is needed to find additional populations of H. novicola and delineate its range in the state. H. novicola was listed as a special concern species in Minnesota in 1996.
Basis for Delisting
Extensive sampling was conducted between 1999-2001 during which several additional populations of H. novicola were found in northern Minnesota. These occured in a variety of habitats suggesting the species isn't restricted by habitat. Based on these data, H. novicola appears to be more common and widespread in Minnesota than it was once thought to be, making special concern status unnecessary. Hydroptila novicola was delisted in 2013.
Caddisfly species can only be identified by examining their abdominal processes under a microscope. No identification manuals are available for species of Hydroptila. Macroscopically, adults of H. novicola are about 3 mm (0.12 in.) long with light brown wings. Larvae of Hydroptila are 3-5 mm (0.12-0.2 in.) long with cases compressed and composed of 2 silken valves covered with a layer of sand grains (Wiggins 1996). Larvae and females of H. novicola are unknown.
Hydroptila novicola has not been positively correlated with its natal habitat. Larvae of Hydroptila are found in both lakes and streams (Wiggins 1996). Collections of this species in 1999 and 2000 were near meandering silt-bottomed streams of various sizes.
Biology / Life History
All known collections of H. novicola adults have occurred in July. Larvae are unknown but likely reach peak maturity in early summer. No further specific life history data are known for this species, but larvae likely feed by piercing the cells of filamentous algae and consuming the contents (Wiggins 1996).
Conservation / Management
No specific conservation measures or management strategies can be developed for this species until the larval habitat is confirmed. Few data are available on general Hydroptila tolerance to anthropogenic disturbances.
Conservation Efforts in Minnesota
Field surveys, in conjunction with a University of Minnesota study on the caddisflies of Minnesota (Houghton et al. 2001), are being conducted to search for additional populations of this species.
References and Additional Information
Houghton, D. C., and R. W. Holzenthal. 2003. Updated conservation status of protected Minnesota caddisflies. The Great Lakes Entomologist 36(1-2):35-40.
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.
Wiggins, G. B. 1996. Larvae of the North American caddisfly genera (Trichoptera), Second edition. University of Toronto Press, Ontario, Canada. 457 pp.