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Stoneflies - Plecoptera: Perlidae of Gunnison County, Colorado

Claassenia sabulosa
Giant Golden Stone, Shortwing Stonefly


Updated 23 February 2024
TSN 102932
Claassenia sabulosa nymph underwater
Claassenia nymph from Cochetopa Creek, August 2016


Nymphs are found under stones in swift riffles where food is abundant in streams and rivers throughout the county.

Life History

Semivoltine, 2 -3 year life cycle, present at 3000m and lower. More common at lower elevations.

Fuller and Stewart (1977) noted C. sabulosa emerges from August to September in the Gunnison River at the Lost Canyon Resort. Nymphs born in October ate whatever was available in the stream. As they grew, they became more selective in their diets. From May to September nymphs selected Chironomids and had a small amount of detritus in their guts. By August they were exclusively carnivorous. Larger nymphs entering their second year ate caddiflies randomly in October and did not eat Chironomid larvae. Their diet was unchanged by the following May. In their second summer, large nymphs consistently selected Chironomids and Mayflies. Large nymphs collected in December had empty guts.

Richardson and Gaufin (1971) found this species is highly carnivorous. Guts contained 91% animal matter. They macerate their prey with well developed mouthparts making identification of gut contents more difficult. Ephemeroptera, Simuliidae, Chironomidae, and Trichoptera larvae were found in their guts. Some guts contained animals swallowed whole, making identification easier. Baetidae and Heptageniidae were common and Ephemerella sp. were also found. Plecoptera nymphs were not common, but when found comprised a large portion of the gut.

Locations Collected

Cement Creek, Lake Fork of the Gunnison, Gunnison River at Soap Creek, Gunnison River at the Lost Canyon Resort, Cebolla Creek, Cochetopa Creek


Older publications may refer to this species as Perla sabulosa.

Good Links

On this website:
Perlidae Introduction

Other Websites:
Photos, Map, Museums, DNA - Barcode of Life Data System

Plecoptera Species File Claassenia sabulosa

Hatch Chart for the Gunnison Gorge & Black Canyon from Cimarron Creek Guides in Montrose

Photos of the Short-Wing Stone in the Yakima River. http://www.worleybuggerflyco.com/insectidentifa/yakima_shortwing_stonefly.htm


Alexander,KD and Stewart,KW 1996 Description and theoretical considerations of mate finding and other adult behaviors in a Colorado population of Claassenia sabulosa (Plecoptera: Perlidae). Annals of the Entomological Society of America 89(2), 290-296.
     Abstract: " Adult behaviors of a Colorado Gunnison River population of Claassenia sabulosa (Banks) are reported. Synchronized emergences began in late July 1992 and early August 1993; each emergence lasted ~2 wk. Eighty-nine percent of nymphs crawled out of shallow water onto emergent stones near the shoreline for transformation, predominantly on dark nights beginning at nightfall. Males emerged significantly earlier in the night than females, their molting times were significantly shorter, and they began immediately searching near the shoreline on isolated stones partially exposed above the water surface. Male mate searching consisted of circling and scrambling over high areas and angular sections of the emergent rock encounter sites. Males encountering a molting female guarded her and began attempting copulation when her genitalia became exposed. Copulations lasted ~62 s, and males subsequently guarded females to delay or reduce further matings by other males. A few unguarded, individual females were observed mating up to 9 times with as many as 5 males. Most females were mated for the 1st time before hardening. Both sexes were active only during the 2-h period just after dusk. When not engaged in mating, they scurried over the water surface between emergent stones and the shore. At all other times, they remained inactive under stones or debris on the stream bank, typically within 1 m of the shoreline. Females with extruded egg masses scrambled over the water surface between emergent stones, washing eggs directly into shallow water. Females were never observed flying and could not be induced to fly. Drumming, by males, did not appear to be a primary requisite for mate finding. Evolution of mate finding behaviors in relation to drumming and other behaviors is discussed, and a paradigm for evolution from a drumming-assisted mate locating method to a search-intensive, encounter site specific method is proposed for this population."

Alexander,KD and Stewart,KW 1997a Further considerations of mate searching behavior and communication in adult stoneflies (Plecoptera); first report of tremulation in Suwallia (Chloroperlidae). In: Ephemeroptera and Plecoptera: Biology-Ecology-Systematics. Eds: Landolt,P; Sartori,M MTL, Fribourg, 107-112.
     They observed adults on the banks of the Gunnison River in 1992 and 1993. They describe Claassenia sabulosa mating behavior as being nocturnal and groundscambling. The males emerge and start running around on the stones at the rivers edge and across the water to new stones looking for females. When they find a female, they usually mate immediately. Sometimes the males drum on the stones, but the females probably cannot hear or feel them.

Allan,JD 1982 Feeding habits and prey consumption of three setipalpian stoneflies (Plecoptera) in a mountain stream. Ecology 63(1), 26-34. Abstract PDF

Banks,N 1900 New genera and species of Nearctic Neuropteroid Insects. Transactions of the American Entomological Society 26:239-259.
     Described as Perla sabulosa.

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
     Quote from page 164: "The genus Claassenia is represented in the Nearctic by one species which is distributed in western North America and east in Canada to the Hudson Bay. Males lack processes on abdominal terga one to nine, contrary to the other members of the Perlinae (fig. 467). The ninth sternum bears a large oval hammer. The subgenital plate of the female is not produced (fig 468). The nymphal occiput is charaterized by a regularly spaced, complete spinule row (fig. 22). The pronotum is fringed laterally with short, peg-like spines."
Quote from page 165: "This species is a top carnivore and the mature nymphs are extremely active. It emerges from June to September. "

Clements,WH 1999 Metal tolerance and predator-prey interactions in benthic macroinvertebrate stream communities. Ecological Applications 9, 1073-1084.
     Abstract: "Predicting responses of benthic communities to contaminants requires an understanding of both direct and indirect effects. I examined the influence of previous exposure to heavy metals on metal tolerance and susceptibility of benthic communities to stonefly predation in experimental streams and field cages. Benthic communities obtained from a reference stream, the Cache la Poudre River (PR), and a metal-polluted stream, the Arkansas River (AR), in Colorado were exposed to a mixture of Cd, Cu, and Zn at ~2× the U.S. EPA chronic criterion level (2.2 µg Cd/L, 24 µg Cu/L, and 220 µg Zn/L) for 10 d in stream microcosms. Effects of metals on survival were significantly greater on mayflies (Ephemeroptera) from the unpolluted PR than from the metal-polluted AR. Metal exposure also significantly increased drift of Rhithrogena hageni, the dominant mayfly in the unpolluted stream but had no effect on invertebrates from the AR. In a second experiment, communities from the two locations were exposed to predatory stoneflies (Claassenia sabulosa) in stream microcosms. Stonefly predation significantly reduced total macroinvertebrate abundance, number of taxa, and abundance of Baetis tricaudatus (Ephemeroptera) and R. hageni. Mayflies from the metal-polluted AR were also more susceptible to stonefly predation, but these results were probably influenced by differences in initial prey density. Results of caging experiments conducted at PR and AR field sites were consistent with results of laboratory experiments and showed that stonefly predation significantly reduced abundance of B. tricaudatus and R. hageni; however, effects of predation in the AR were relatively weak because of high prey immigration. Results of these experiments suggest that abiotic factors influence the outcome of species interactions in metal-polluted streams. Ecosystems disturbed by contaminants, particularly those polluted for relatively long periods of time, provide excellent opportunities to study these interactions."

DeWalt,RE; Hopkins,H; Neu-Becker,U and Stueber,G 2024 Claassenia sabulosa (Banks, 1900). Plecoptera Species File. Retrieved on 2024-01-13 at https://plecoptera.speciesfile.org/otus/932374/overview
     I read one or another of the stonefly webpages from Plecoptera Species File regularly and sometimes add papers or other information I learned to the website you're reading https://www.gunnisoninsects.org/ :-)

DeWalt,RE and Stewart,KW 1995 Life histories of stoneflies (Plecoptera) in the Rio Conejos of southern Colorado. Great Basin Naturalist (55) 1-18. PDF

Dosdall,LM and Giberson,DJ 2014 Stoneflies (Plecoptera) of the Canadian Prairie Provinces. Arthropods of Canadian Grasslands, 3: 201-229. PDF
     Nymph photo on page 202.

Fuller,RL and Stewart,KW 1977 The food habits of stoneflies (Plecoptera) in the Upper Gunnison River, Colorado. Environmental Entomology (6) 293-302.
     Abstract: "Gut contents of 1,463 stonefly nymphs, comprising 10 species, from the Gunnison River, Colorado, were analyzed from Dec., 1974-Oct., 1975, in relation to food availability. Pteronarcella badia fed primarily on detritus and moss. Perlidae and Perlodidae mature nymphs were all carnivorous, but showed considerable seasonal-developmental shifting in diets and preference during earlier stages. Early instar Isoperla fulva nymphs were herbivore-detritivores, then gradually shifted through an omnivorous to carnivorous diet as development proceeded. Claassenia sabulosa and Hesperoperla pacifica remained carnivorous throughout development. Dominant prey groups were chironomids, mayflies and caddisflies. Horn's Coefficient of Dietary Overlap showed significance among all predator species for major food categories, but subtle mechanisms such as prey species-and size-selectivity and temporal succession provided sufficient partitioning of the abundant food resources to allow for coexistence. Large Claassenia sabulosa nymphs in August selected more mayflies after dark than in the afternoon. No behavioral selection by predacious stoneflies was indicated for the chironomids Ablabesmyia sp., Cricotopus sp., Prodiamesa sp., and Rheotanytarsus sp."

Fuller,RL and Stewart,KW 1979 Stonefly (Plecoptera) Food habits and prey preference in the Dolores River, Colorado. American Midland Naturalist, 101(1) 170-181. First page

Hassage,RL; DeWalt,RE and Stewart,KW 1988 Aggregation of Pteronarcella badia nymphs and effects of interaction with Claassenia sabulosa (Plecoptera). Oikos, pp.37-40.
     Abstract: " Claassenia sabulosa (Banks) and Pteronarcella badia (Hagen) stonefly nymphs were examined for distributional responses in an experimental setting. In treatments with single individuals and groups of four, P. badia, a shredder, distributed itself in proportion to the available surface area among fibrous, non-food substrates of different sizes. In treatments with four and fourteen P. badia, the nymphs demonstrated aggregation, often with body contact. Its distribution became random and significantly different from substrate surface area in the presence of C. sabulosa, a predator, indicating an interspecific interaction."

Hassage,RL and Stewart,KW 1990 Growth and voltinism of five stonefly species in a New Mexico mountain stream. The Southwestern Naturalist, 35 (2)130-134.
     Abstract: "The nymphal growth and emergence of five stonefly species were determined by intensive sampling of leaf packs and mineral substrate in a riffle of a mountain stream in northern New Mexico. Isoperla fulva (n = 781) and Triznaka signata (n = 421) had late summer recruitment and slow univoltine life cycles, while nymphs of Prostoia besametsa (n = 2,009) were recruited in late fall and had a fast univoltine life cycle. Nymphs of Skwala parallela were apparently recruited in early summer or spring and were also univoltine. Classenia sabulosa had a semivoltine life cycle with nymphs recruited in late summer and early fall. Although they were of similar size at summer recruitment, nymphs of T. signata were generally smaller than those of I. fulva in fall and winter. Nymphs of P. besametsa grew rapidly during the coldest part of the year, achieving size equivalence with T. signata in December and February. The greatest nymphal growth rate was displayed by S. parallela; nymphs of this species reached 3.5 mm in head capsule width (HCW) by the end of the fall. Growth of C. sabulosa (which ultimately reaches 4-5 mm HCW) was much slower; this species required more than a single year of growth. Adult P. besametsa were first collected in April (n = 130) when they were most abundant; a few were also collected in May (n = 4) and June (n = 1). Skwala parallela adults (n = 13) were only collected in April. Adults of I. fulva (n = 37) were collected only during June, while those of T. signata were abundant in June (n = 22) and July (n = 33) with a single individual collected in August."

Heinold,B 2010 The mayflies (Ephemeroptera), stoneflies (Plecoptera), and caddisflies (Trichoptera) of the South Platte River Basin of Colorado, Nebraska, and Wyoming. M.S. Thesis, Colorado State University, Fort Collins, CO 375 pages. 148 distribution maps. PDF

Illies,J 1966 Katalog der rezenten Plecoptera. Das Tierreich - Eine Zusammenstellung und Kennzeichnung der rezenten Tierformen. (Das Tierreich) 82:435

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 395: "The beautifully patterned nymph of this species can be abundant in many medium to large Mountain and Plateau streams. The brachyterous males can be found under loose stones along the edges or moving from rock to rock, searching for females at night. DeWalt and Stewart (1995) presented the life history of this species in Colorado, and Alexander and Stewart (1996) discussed the adult biology."

Malison,RL; DelVecchia,AG; Woods,HA; Hand,BK; Luikart,G and Stanford,JA 2020 Tolerance of aquifer stoneflies to repeated hypoxia exposure and oxygen dynamics in an alluvial aquifer. Journal of Experimental Biology, 223(16). PDF

Malison,RL; DelVecchia,AG; Woods,HA; Hand,BK; Luikart,G and Stanford,JA 2020 Tolerance of aquifer stoneflies to repeated hypoxia exposure and oxygen dynamics in an alluvial aquifer. Journal of Experimental Biology, 223(16). PDF

Martin, C.A., Luoma, S.N., Cain, D.J. and Buchwalter, D.B., 2007 Cadmium ecophysiology in seven stonefly (Plecoptera) species: delineating sources and estimating susceptibility. Environmental science & technology, 41(20), pp.7171-7177. PDF

Nelson,CH 2009 Surface ultrastructure and evolution of tarsal attachment structures in Plecoptera (Arthropoda: Hexapoda). Aquatic Insects, (31)523-545. Html
     The author used scanning electron microscopy (SEM) to image the plantar surfaces of the stonefly tarsomeres and pretarsus of Claassenia sabulosa and a number of other species.
Quote from page 533 " Tarsus and pretarsus of this species shown in Figure 32 resemble the previously described perlodid Megarcys signata shown in Figure 31, except that tarsomere 1 is approximately one-third the length of tarsomere 3 and the arolium plantar surface bears a variable number of setae.quot;

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"

Richardson,JW and Gaufin,AR 1971 Food habits of some western stonefly nymphs. Transactions of American Entomological Society 97, 91-121.

Sanders,HO and Cope,OB 1968 The relative toxicities of several pesticides to naiads of three species of stoneflies. Limnology and Oceanography 13(1) 112-117. First page

Sheldon,AL 1980 Coexistence of perlid stoneflies (Plecoptera): predictions from multivariate morphometrics. Hydrobiologia, 71(1) 99-105. 1st two pages

Shepard,WD and Stewart,KW 1983 Comparative Study of Nymphal Gills in North American Stonefly Genera and a New, Proposed Paradigm of Plecoptera Gill Evolution. Miscellaneous Publications of the Entomological Society of America 13:1-57
     Illustration of nymphal osmobranchiae and gills on page 42.

South,EJ; Skinner,RK; DeWalt,RE; Davis,MA; Johnson,KP; Teslenko,VA; Lee,JJ; Malison,RL; Hwang,JM; Bae,YJ and Myers,LW 2021 A new family of stoneflies (Insecta: Plecoptera), Kathroperlidae, fam. n., with a phylogenomic analysis of the Paraperlinae (Plecoptera: Chloroperlidae). Insect Systematics and Diversity, 5(4), p.1. PDF
     Table 1 indicates a C. sablosa specimen was used in the phylogenetic analyses.

Stark,BP and Gaufin,AR 1976 The nearctic genera of Perlidae (Plecoptera). Miscellaneous Publications of the Entomological Society of America 10, 1-80.

Stark,BP and Sivec,I 2010 Systematic notes on the genus Claassenia Wu (Plecoptera: Perlidae), with description of a new species. Illiesia 6(24):303-314. PDF

Stewart,KW 2001 Vibrational communication (drumming) and mate-searching behavior of stoneflies (Plecoptera); evolutionary considerations. In Trends in Research in Ephemeroptera and Plecoptera (pp. 217-225). Springer US.
     Abstract: "A long recognized but little explored mode of intersexual communication in insects is use of low-frequency substrate-borne vibrational signals. Representatives of 10 insect orders are known to have adopted this mode; range of communication, informational content and receiver integration of signals and energy costs are discussed. Arctoperlarian stoneflies represent the epitome of evolution of vibrational communication. Their ancestral signals were monophasic volleys of evenly spaced drumbeats. Derived signals to achieve species-specificity and possibly to enable sexual.selection or some measure of reproductive fitness has involved modification of the ancestral form toward complex signals through: (1) changes in the rhythmic patterning of calls, (2) patterns of ♂-♀ duetting, and/or changes in the method of signal production such as rubbing or tremulation. Proposed paradigms for the evolution of vibrational communication and evolution of signal patterns are presented, with examples of the signals of several arctoperlarian species. The entire mating system of Arctoperlaria is discussed, and searching behavior in relation to vibrational communication is presented for Pteronarcella badia, Claassenia sabulosa, Perlinella drymo and Suwallia sp."

Stewart,KW and Stark,BP 2002 Nymphs of North American Stonefly Genera. 2nd edition The Caddis Press, Columbus, Ohio. 510 pages.
     Illustration of nymph (from the Gunnison River in Gunnison County!) habitus on pages 333-334 figure 13.13-13.14

Stewart,KW and Szczytko,SW 1983 Drift of Ephemeroptera and Plecoptera in two Colorado rivers. Freshwater Invertebrate Biology. 2(3)117-131. PDF

Thorp,RA; Monroe,JB; Thorp,EC; Wellnitz,T and Poff,NL 2007 Food and habitat relationships of Claassenia sabulosa (Plecoptera: Perlidae) in the upper Colorado River, Colorado. Western North American Naturalist 67(1) 57-62. PDF
     Abstract: " Streambed surveys were conducted along the upper Colorado River, Colorado, to describe the distributions of Claassenia sabulosa larvae in relation to current speed and to determine their diets. We also addressed diel feeding periodicity by sampling during both day and night. Claassenia sabulosa was more abundant in riffle habitats than in runs. A positive relationship existed between C. sabulosa abundance and stream current, with larval size increasing with current speed. Chironomidae, Baetidae, and Simulidae collectively accounted for 93% of the prey found in stonefly guts; however, these categories were not consumed equally by all C. sabulosa. Smaller C. sabulosa primarily ate chironomids, and larger individuals consumed more baetids. Only a slight difference existed in the percentage of empty guts between night- and day-collected stoneflies, and ranges of prey per gut at night were higher than those in the day, suggesting that these stoneflies may forage more intensively at night."

Thorp,RA; Kondratieff,BC; Thorp,EC; Odenbeck,PB and Jarrett,MJ 2008 The life cycles of Claassenia sabulosa and Hesperoperla pacifica (Plecoptera: Perlidae) in two Colorado streams. Western North American Naturalist, 68(3) 311-318. PDF
     Abstract: "We compared the life cycles of Claassenia sabulosa (Banks 1900) and Hesperoperla pacifica (Banks 1900) (Plecoptera: Perlidae) in allopatry and sympatry by studying 4 populations in 3 streams of the South Platte River Watershed, Colorado. We estimated 2-year life cycles for both C. sabulosa and H. pacifica in allopatry and sympatry. Evidence of egg diapausing and extended larval recruitment was noted for both species in allopatry and sympatry. There were no apparent differences in larval growth, larval recruitment, or adult emergence periodicity between allopatric and sympatric populations of C. sabulosa. In contrast, allopatric and sympatric H. pacifica populations exhibited differences in the timing of larval growth, larval recruitment, and adult emergence. We feel that the differences in the life cycles of these populations were likely related to water temperature because a substantial water temperature difference (degree days of 1761 and 2563) occurred between study reaches. In sympatry, H. pacifica adults began emerging 2 weeks earlier than C. sabulosa, when water temperature reached 9°C. The emergence of H. pacifica was synchronous and male biased. The emergence of C. sabulosa was protandrous and male biased and began when water temperature reached 17°C. Claassenia sabulosa emergence was extended and lasted for 6 weeks during July and August. The abundance of C. sabulosa adults during this period corresponded closely to fluctuations in water temperature."

The United States Geological Survey (USGS) National Water Quality Assessment Data Warehouse (NAWQA) shows this species is present in Gunnison County. Data as of 1Sep2005

Ward,JV, Kondratieff,BC and Zuellig,RE 2002 An Illustrated Guide to the Mountain Stream Insects of Colorado. 2nd ed. University Press of Colorado, Boulder, Colorado. 219 pages.
     Illustration of C. sabulosa nymph on page 71, figure 31.

Ziegler,DD and Stewart,KW 1977 Drumming behavior of eleven Nearctic stonefly (Plecoptera) species Annals of the Entomological Society of America. 70(4)495-505.

Zuellig,RE; Heinold,BD; Kondratieff,BC and Ruiter,DE 2012 Diversity and Distribution of Mayflies (Ephemeroptera), Stoneflies (Plecoptera), and Caddisflies (Trichoptera) of the South Platte River Basin, Colorado, Nebraska, and Wyoming, 1873-2010.U.S. Geological Survey Data Series 606, 257 p. PDF - caution 46MB

Zwick,P 1973 Insecta: Plecoptera Phylogenetisches System und Katalog. Das Tierreich - Eine Zusammenstellung und Kennzeichnung der rezenten Tierformen., 94, 465 pp.



subgenital plate


genital hooks


Brown,WS 2004 Stoneflies (Plecoptera) of Gunnison County, Colorado