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Stoneflies - Plecoptera: Chloroperlidae of Gunnison County, Colorado

Key to Adult Sallflies or Triznaka

1a. Anterior black mark on head as long as wide, often extending posteriorly to medain ocellus; median pronotal stripe broad, little produced laterally on posterior margin; little or no pigmentation on pronotal rugosities.
1b. Anterior mark on head twice as wide as long, not extending to median ocellus; median pronotal stripe much produced laterally at anterior and posterior margins; heavy pigmentation on pronotal rugosities.

Aedeagus with numerous large dark ventral spines at base (Baumann and Kondratieff 2008, figs. 12-14, 22, 29); pronotal rugosities strongly marked with black


Key and drawings modified from:
Baumann,RW, Gaufin,AR and Surdick,RF 1977 The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208.

Baumann,RW and Kondratieff,BC 2008 A review of the western North American genus Triznaka (Plecoptera: Chloroperlidae) with a new species from the Great Basin, USA. Proceedings of the Entomological Society of Washington 110(2)345-362.

Kondratieff,BC and Baumann,RW 2012 A new species of the western North American genus Triznaka from Oregon (Plecoptera: Chloroperlidae). Illiesia, 8(02)10-15. PDF
     Provides a key to all known North American species of Triznaka.

Good Links

Key to Male Triznaka
Brown, WS 2004 Plecoptera or Stoneflies of Gunnison County, Colorado