Stoneflies - Plecoptera: Capniidae of Gunnison County, Colorado
Introduction to Capnia Pictet 1841
Snowflies, Winter Black stoneflies,Small Winter Stoneflies, Tiny Winter Blacks
Updated 20 Sept 2020
Provisional Species List
On this website:
Key to Capniidae Nymphs
Key to Capniidae Males
Key to Capniidae Females
Photo - from the Tree of Life by Riley Nelson http://tolweb.org/tree/eukaryotes/animals/arthropoda/hexapoda/plecoptera/capniidae/capniaalternative.html
PAN Pesticides database:
Baumann,RW 1979 Nearctic stonefly genera as indicators of ecological parameters (Plecoptera: Insecta). The Great Basin Naturalist, 241-244. PDF
The genus Capnia is present in both cold and warm lentic (stream or river) habitats, as well as cold lentic (lake) habitats.
Abstract: "Selected stonefly genera found in North America are classified as to their occurrence in: cold lotic, warm lotic, or lentic habitats. Most genera occur only in the cold lotic, but several occur both in cold and warm lotic systems. Few are found exclusively in warm lotic habitats and almost none in lentic. Lake or true lentic inhabits are found to usually be cold lotic species which have adapted to life in the wave-washed shores of cold mountain lakes. Even though data at the specific level would be even more useful, especially where different faunal regions are involved, stoneflies are probably the best insect indicators of aquatic environmental quality at the generic level."
Baumann,RW, Gaufin,AR and Surdick,RF 1977 The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208.
Quoted from page 61: "This genus is comprised of small, black species most of which are less than 10 millimeters in length. The cerci are as long as or longer than the entire body. The male epiproct is long and recurved over the abdomen in the form of a probe (fig 184). The male ninth sternum is usually modified or produced (fig. 175).
Capnia contains a large number of species and species complexes. When the genus is studied in more detail it is quite likely that it will be divided into several taxonomic units." See Nelson and Baumann, 1989 for a revision of this genus.
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
They collected Capnia coloradensis, C. confusa and C. vernalis among many other species. This river is southeast of Gunnison county, but has many of the same stoneflies.
Dodds GS and Hisaw FL. 1925. Ecological studies on aquatic insects. IV. Altitudinal range and zonation of mayflies, stoneflies and caddisflies in the Colorado Rockies. Ecology 6(4)380-390. Abstract PDF
Donald,DB 1980 Deformities in Capniidae (Plecoptera) from the Bow River, Alberta. Canadian Journal of Zoology 58, 682-686.
Gray,LJ and Ward,JV 1979 Food habits of stream benthos at sites of differing food availability. American Midland Naturalist 102 1, 157-167.
Hanson,JF 1946 Comparative morphology and taxonomy of the Capniidae (Plecoptera) American Midland Naturalist 35(1) 193-249 first page
Khoo,SG 1968 Experimental studies on diapause in stoneflies. I. Nymphs of Capnia bifrons (Newman). In Proceedings of the Royal Entomological Society of London. Series A, General Entomology 43 (1-3) 40-48. Oxford, UK: Blackwell Publishing Ltd.
Nebeker,AV and Gaufin,AR 1967 Geographic and seasonal distribution of the family Capniidae of western North America (Plecoptera). Journal of the Kansas Entomological Society 40(3)415-421 Abstract and first page
Nelson,RC; Baumann,RW 1989 Systematics and distribution of the winter stonefly genus Capnia (Plecoptera: Capniidae) in North America. Great Basin Naturalist 49, 289-363. PDF
Nelson,RC and Kondratieff,BC 1988 A new species of Capnia (Plecoptera: Capniidae) from the Rocky Mountains of Colorado. Entomological News 99 2, 77-80.
Nelson,SM and Roline,RA 1999 Relationships between metals and hyporheic invertebrate community structure in a river recovering from metals contamination. Hydrobiologia 397, 211-226.
They found Capnia sp. primarily in the hyporheic samples. The mean density in the surface samples was only 129 animals/meter² while in the hyporheic zone there was a mean of 11,524 animals/meter². That's two orders of magnitude more Capnia larvae down deep in the stream gravels compared to the surface substrate.
Pennack,RW and Ward,JV 1986 Interstital faunal communities of the hyporheic and adjacent groundwater biotopes of a Colorado mountain stream. Archiv für Hydrobiologie Suppl. 74 3, 356-396.
They found Capnia nymphs in the hyporheic zone of the South Platte river in the Front Range of Colorado at 1863 meters elevation.
Richardson, JS 2001 Life cycle phenology of common detritivores from a temperate rainforest stream. Hydrobiologia 455 (1) 87-95. DOI - 10.1023/A:1011943532162
Abstract: The timing of life cycles, including growth rates, was determined for eight common species of detritivorous insects in a second-order stream in southwestern British Columbia, Canada. Six of the species (Zapada cinctipes, Z. haysi, Malenka californica, M. cornuta, Capnia sp., and Lepidostoma roafi) had simple, univoltine life cycles. The leuctrid stonefly Despaxia augusta has a 2-year life cycle, with an apparent egg diapause of about 6 months. The chironomid Brillia retifinis produced at least three generations per year. The major growth periods for the set of species considered here span the entire year. Adults of several species exhibited seasonal declines in size at emergence, but one species had larger adults as the emergence period proceeded. Closely related taxa had more similar life cycle timing than more distantly related species suggesting a degree of phylogenetic constraint in phenology of their life cycles. The influence of the timing of leaf drop on timing of life cycles for these animals does not fit with proposed scenarios based on fast and slow leaf processing rates.
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. "
Short,RA; Canton,SP and Ward,JV 1980 Detrital processing and associated macroinvertebrates in a Colorado mountain stream. Ecology, 61(4), 727-732. PDF
Short,RA and Ward,JV 1981 Trophic ecology of three winter stoneflies (Plecoptera). American Midland Naturalist 105, 341-347.
Stewart,KW; Bottorff,RL; Knight,AW; Moring,JB 1991 Drumming of four North American euholognathan stonefly species, and a new complex signal pattern in Nemoura spiniloba Jewett (Plecoptera:Nemouridae). Annals of the Entomological Society of America 84 2, 201-206.
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 206 and 207: "Holarctic; 52 Nearactic species, distributed mostly in the West and Midwest. Adults small, black, under 12mm. Winter and spring emergence from February-April in the southern Ricky Mountain to May-July in the Yukon and high elevations. Nymphs light to medium brown in mineral substrates of small and large streams. The few known life histories suggest that most North American Capnia species probably have univoltine, fast life cycles with summer nymphal diapause. Nymphs are largely detritovores and many shred deciduous leaves in streams, The North American species in this genus were recently revised by Nelson and Baumann (1989). "
Brown, Wendy S. 2004 Plecoptera or Stoneflies of Gunnison County, Colorado
"Science has never drummed up quite as effective a tranquilizing agent as a sunny spring day." --W. Earl Hall