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Stoneflies - Plecoptera:Chloroperlidae of Gunnison County, Colorado

Alloperla severa - Western Sallfly

(Hagen 1861)
Updated 22 May 2016


Adults are bright green, no abdominal stripe.

Life History

Adults emerge from May to September

Locations Collected

Widespread in Western North America, medium to small rivers. Recent research (Baumann and Kondratieff, 2008) restricts this species to the northern portion of North America. Our local species are likely to be Alloperla thalia.


The genus Alloperla was previously included in Perla. Older publications may refer to this species as Perla severa. This species was recently split into three taxa. Alloperla thalia is present in Colorado, we need to check our identifications!

Good Links

On this website:
Key to Alloperla females
Key to Alloperla males
Comparison of the two local species of Alloperla
Alloperla pilosa

Other Websites:
Adult Photo - Alloperla sp. from the Tree of Life http://tolweb.org/tree/eukaryotes/animals/arthropoda/hexapoda/plecoptera/slideshows/pleco1/sld033.htm

Photos, Map, Museum specimens, DNA - Barcodinglife.org


Baumann,RW, Gaufin,AR and Surdick,RF 1977 The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208. PDF
     "Discussion. - This species is common in creeks in the Rocky Mountain region. The adults emerge from May to September." Figure 484 Male terminalia, dorsal view, Figure 485 Male terminalia lateral view, Fihure 486 female terminalia ventral view on page 169.

Baumann,RW and Kondratieff, BC 2008 The Alloperla severa complex (Plecoptera: Chloroperlidae) of western North America. Illiesia 2008 4(6):66-75. PDF
     The authors split A. severa into three species A. severa, A. elevata and A. thalia. A. severa is restricted to northern North America. Alloperla thalia is present in Colorado and may be the species we have been calling A. severa.

Hagen,HA 1861 Synopsis of the Neuroptera of North America with a list of South American species. Smithsonian Miscellaneous Collections 4, 1-344.
     Described as Perla severa. Hagen's Glossary (pdf)

Lyon,ML and Stark,BP 1997 Alloperla (Plecoptera: Chloroperlidae) of western North America. Entomological News 108 5, 321-334.

Newell,RL; Baumann,RW and Stanford,JA 2008 Stoneflies of Glacier National Park and Flathead River basin, Montana. International Advances in the ecology, zoogeography, and systematics of mayflies and stoneflies. University of California Publications in Entomology, Berkeley and Los Angeles, pp.173-186. PDF
     Quote from page 176: "Stoneflies recorded from hyporheic habitats (pumped wells) included: Alloperla severa, Capnia confusa, Claassenia sabulosa, Diura knowltoni, Hesperoperla pacifica, Isocapnia crinita, I. grandis, I. integra, I. vedderensis, Isoperla fulva, Kathroperla, Paraperla frontalis, and P. wilsoni"

Ricker,WE 1992 Origin of stonefly names proposed by Ricker and collaborators. Perla, 18(1) 12 pages. PDF
      Quote from page 3: "*thalia Ricker 1952. Syn. severa Hagen. Thalia is the Muse of comedy, but I have forgotten what was amusing here. Hagen's name is evidently from Russian sever = north, the type being from the "Island of Unga, Russian America"."


subgenital plate

Brown, WS 2004 Stoneflies of Gunnison County, Colorado