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Stoneflies - Plecoptera: Nemouridae of Gunnison County, Colorado

Zapada frigida - Frigid Forestfly

(Claassen) 1923
Updated 29 Dec 2016
TSN 102601
Zapada oregonensis groups and Z. haysi nymph comparison of cervical gills

The animal on the left is a Zapada haysi/oregonensis group and the animal on the right is Z. frigida. Notice the long thin cervical gills on the Z. frigida nymph.


This animal is present in Splains Gulch and the Coal Creek drainage. Also, look for Z. frigida at higher elevations and in smaller spring fed creeks. The genus Zapada was previously named Nemoura. Older publications may refer to this species as Nemoura frigida.

Good Links

On this website:
Introduction to Zapada

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Photo - Nymph from Michael Wigle Photography.
     Look at the cervical gills, which appear as white filaments under the neck.


Baumann, RW Gaufin, AR, Surdick, RF 1977: The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208.
     In the keys, adult wings are uniformly brown, Other Zapada species have mottled wings. Adult males, females and larvae all have cervical gills (gills on their neck) which are 12-15 times as long as wide. This is in contrast to Z. oregonensis group and Z. haysi larvae which have 4 simple gills that are less than 10 times as long as wide.
Quote from page 46: "The nymphs are usually found in small headwater streams and spring fed creeks. This species is found primarily in the northwest but is never common. The adults emerge from March to August."

Bottorff,RL and Bottorff,LD 2007 Phenology and diversity of adult stoneflies (Plecoptera) of a small coastal stream, California. Illiesia 3(1):1-9 PDF 292 Kb

Claassen,PW 1923 New species of North American Plecoptera. Canadian Entomologist 55, 257-263,281-292.
     Described as Nemoura frigida.

Jones,TS and Resh,VH 1988 Movements of adult aquatic insects along a Montana (USA) springbrook. Aquatic insects, 10(2), 99-104. PDF
     Abstract: " The occurrence and movement patterns of adult insects along a forested springbrook near Flathead Lake, Montana, USA, were studied during three 15-day periods from 19 June through 9 August 1985, using a two-sided Malaise trap. Of the Plecoptera, numbers of males and gravid females of Malenka flexura gravid females of Zapada frigida and total numbers of Paraperla wilsoni were significantly higher for downstream-flying adults during one to three periods. Of the Trichoptera, numbers of males of Anagepetus debilis were significantly higher for upstream flying adults during one period, and males of Lepidostoma cascadense and gravid females of L. spicata were significantly higher for downstream-flying adults during another period. In none of the 26 species examined in these three orders did females show a statistically significant pattern of upstream flight."

Kondratieff,BC and Baumann,RW 2002 A review of the stoneflies of Colorado with description of a new species of Capnia (Plecoptera: Capniidae). Transactions of American Entomological Society 128 3, 385-401.
     Quote from page 392: "Zapada frigida is a common species of the Pacific Northwest, but has only been collected in Boulder, Hinsdale, Summit and Grand counties, from several areas of the high mountain region. "

Needham,JG and Claassen,PW 1925 A Monograph of the Plecoptera of North America. Entomological Society of America, Lafayette, Indiana. 397 pages.
     Discussed as Nemoura frigida.

Stark,BP; Oblad,BR; Gaufin,AR 1973 An annotated list of the Stoneflies (Plecoptera) of Colorado Part I. Entomological News 84 9, 269-277.

Brown,WS 2005 Plecoptera or Stoneflies of Gunnison County, Colorado