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Plecoptera: Chloroperlidae of Gunnison County, Colorado

Introduction to Alloperla - Sallflies

Banks 1906
Updated 2 Mar 2015

Provisional Species List

Alloperla pilosa
Alloperla severa probably not present, see A. thalia below)
Alloperla thalia


Of the seven species of Alloperla in western North America, Gunnison County has two. "Adult Alloperla are distinguished from most other chloroperlid genera by their pale green or yellow body coloration, the lack of dark markings on the head and pronotum, and the reduced anal area of the hind wing with less than five anal veins" (Lyon and Stark 1997).

Good Links

On this website:
Key to Alloperla females
Key to Alloperla males

Other Websites:
Photo - Adult from the Tree of Life


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
     Quoted from page 167: "The adults of the genus Alloperla are bright green except for the yellow A. delicata. All but one species, A. pilosa, lack a dark abdominal stripe (fig 558). Some dusky patches may mark the head and pronotum, but they usually are free from dark coloring. In most species, the epiproct sonsists of a long curved rod-like base with a small process at the tip (fig 482)." They provide male and female keys as well as illustrations, geographic range, distribution and discussions for the 5 species of Alloperla found in the Rocky Mountains.

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.

Frison, T.H. 1935 New North American species of the genus Alloperla (Plecoptera: Chloroperlidae). Transactions of the American Entomological Society, 61:331-344.

Lyon,ML; Stark,BP 1997 Alloperla (Plecoptera: Chloroperlidae) of western North America. Entomological News 108 5, 321-334.
     They review all seven western species of Alloperla and present a key to adult males and females with eggs. They also provide descriptions and scanning electron micrographs of eggs and male epiprocts. Drawings of female subgenital plates are included.

Robinson,CT and Minshall,GW 1986 Effects of disturbance frequency on stream benthic community structure in relation to canopy cover and season. Journal of the North American Benthological Society, 237-248. PDF
     Abstract: " Field experiments were conducted to examine the effects of disturbance frequency on invertebrates and periphyton colonizing bricks in a third order Rocky Mountain (USA) stream. After an initial colonization period (30 days), sets of bricks were turned over at intervals of 0, 3, 9, 27, or 54 days. Invertebrate species richness and density were reduced as disturbance frequency increased. These trends were evident for both seasons (summer and fall) and sites (open vs. closed canopy). Invertebrate species diversity (H') displayed no effect during the fall experiment; however, H' was reduced at high frequencies of disturbance during the summer experiment. Baetis tricaudatus was the most abundant invertebrate on the substrata at both sites and seasons. Alloperla, Baetis, Cinygmula, Chironomidae, Drunella grandis, Hydropsyche, and Seratella tibialis increased in absolute abundances as disturbance frequency decreased. Four other abundant taxa (Capnia, Cleptelmis, Glossosoma, and Isoperla) displayed no clear response to disturbance in either absolute or relative abundances. Species in low abundance tended to colonize only the less frequently disturbed bricks. During both seasons, periphyton biomass increased as disturbance frequency decreased at the open canopy site, while no trend was apparent at the closed canopy site. Periphyton accumulation monitored over time and among treatments revealed that frequent disturbances maintained low standing crops at an open canopy site. These data suggest that disturbance frequency can directly influence the benthic community at the scale of individual rock "islands" by reducing invertebrate richness, total animal density, and periphyton biomass. The effect of disturbance on species diversity (H') was seasonal, further emphasizing the importance of considering seasonality in stream field studies. "

Roline,R 1988 The effects of heavy metals pollution of the upper Arkansas River on the distribution of aquatic macroinvertebrates. Hydrobiologia 160: 3-8.
     They sampled the Arkansas River upstream and downstream of mine drainage and clean water inputs in 1979 and 1980. After compositing 3 surber samplers in the field, they identified the macroinvertebrates to genus level and used a diversity index to evaluate the health of the macroinvertebrate community. Higher diversity is better. Diversity decreased downstream of heavy metal pollution from the Leadville Drain and California Gulch and increased downstream of clean water inputs.
Quote from page 8: "The plecopterans, Alloperla and Isoperla, were collected at all stations, showing a relative tolerance to heavy metals pollution. "

Stewart,KW and Ricker,WE 1997 The stoneflies of the Yukon. pgs 201-222 in Danks,HV and Downes,JA (Eds.), Insects of the Yukon. Biological Survey of Canada (Terrestrial Arthropods), Ottawa. 1034 pp.
     Quote from page 212: Eastern Palaearctic and Nearctic; 29 Nearctic species, only 7 of which are western, distributed from Kodiak Island, ALaska and Yukon to California and Wyoming. Adults yellow or light green, 6-12mm. Summer emergers, April in Mississippi to June-August in ALaska and Yukon. No detailed accounts of nymphal development, trophic dynamics or habitat partioning have been published.

Cerci of Alloperla Nymph
Cerci of Nymph
Epiproct of Male (the center thing is the epiproct, hooked up towards the viewer)
Epiproct of Male (the center thing is the epiproct, hooked up towards the viewer)
Lacinia of Nymph mouth
Lacinia of Nymph mouth
Pronotum of Nymph thorax
Pronotum of Nymph thorax

Brown, Wendy S. 2004 Plecoptera or Stoneflies of Gunnison County, Colorado

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