Plecoptera: Perlidae of Gunnison County, ColoradoHesperoperla pacifica
Golden Stonefly, Willow fly, Pacific Stonefly, Small golden stone, Golden stone, Big Golden stonefly(Banks 1900)
Updated 1 Mar 2010
TSN 102972
Habitat
Nymphs live in swift water in streams and rivers throughout the county and nation.
Life History
H. pacifica remain in the stream as a nymph for 2 or 3 years, the fancy word for that is semivoltine.
Richardson and Gaufin (1971) found that H. pacifica was primarily a carnivore eating 88% animal matter and 12% plant matter. They ate primarily Ephemeroptera, Chironomidae and Trichoptera. The highest proportion of chironomidae larve were found in specimens from the Taylor River. Richardson and Gaufin think a large part of the detritus and plant matter in the guts of these animals is from the gut of their prey.
Fuller and Stewart (1977) noted this species is semivoltine and emerged from June to July in the Gunnison River at Lost Canyon Resort. First year nymph guts were 85% animal material from their first appearance in August - September through the following July. Chironomidae larve always had a high electivity and were over 60% of the gut contents in all months except May. In May Ephemeroptera nymphs showed a higher electivity. Small numbers of other aquatic insects appeared in the guts, but electivity for them was always negative. Second year nymphs also fed on animal matter (85%) in most months. They elected to eat more Trichoptera larvae in the fall and winter inspite of the fact that Chironomid larvae were abundant. By the next June-August, mature nymphs shifted back to Chironomids. H. pacifica showed a consistent negative electivity for Ephemeroptera nymphs except in May during the first year of their development. They either avoided feeding on the common Oligochaetes from July through September or did not encounter them while hunting.
Local Research Results
Small predators preyed on small prey and big predators showed a preference for medium sized prey. Size selectivity varied with predator size. Percent attacks per encounter by small predators were strongly biased towards small prey, Large stoneflies were weakly biased towards large prey. Capture success was greater and handling times were shorter with small prey compared to large prey (Allan et al 1987b).
Locations Collected
Taylor River, Lake Fork of the Gunnison River, Gunnison River at the Lost Canyon Resort.
Notes
Older publications may refer to this species as Acroneuria pacifica.
Good Links
On this website:
Perlidae Introduction
Other Websites:
References
Allan,JD; Flecker,AS; McClintock,NL (1987): Prey preference of stoneflies: sedentary vs mobile prey. Oikos 49(3), 323-331.
Allan,JD; Flecker,AS; McClintock,NL (1987): Prey size selection by carnivorous stoneflies. Limnol. Oceanogr. 32(4), 864-872.
Banks N. 1900 New genera and species of Nearctic Neuropteroid Insects. Transactions of the American Entomological Society 26:239-259.
Described as Acroneuria pacifica.
Baumann,RW; Gaufin,AR; Surdick,RF 1977 The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208.
Quote from page 162: "This species is the most widely distributed stonefly species in the Rocky Mountains. Throughout its range it exibits a wide variation in size, wing length, coloration and shape of the female subgenital plate. However, in all cases studied, the aedeagus and ova are uniform. The adults emerge from April to October."
Buchwalter,DB; Cain,DJ; Martin,CA; Xie,L; Luoma,SN; Garland,JT 2008 Aquatic insect ecophysiological traits reveal phylogenetically based differences in dissolved cadmium susceptibility. Proceedings of the National Academy of Sciences 105 24, 8321-8326.
DeWalt,R Edward; Stewart,Kenneth W (1995): Life histories of stoneflies (Plecoptera) in the Rio Conejos of southern Colorado. Great Basin Naturalist 55, 1-18.
Fuller,RL; Stewart,K,W 1977 The food habits of stoneflies (Plecoptera) in the Upper Gunnison River, Colorado. Environmental Entomology 6, 293-302.
Kondratieff,BC; 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: " This extremely widespread western North American species can be collected in almost all types of streams, ranging from rheocrenes to large rivers throughout the Mountain and Plateau Provinces of Colorado."
Molles,MC and Pietruszka,RD 1983 Mechanisms of prey selection by predaceous stoneflies: roles of prey morphology, behavior and predator hunger. Oecologia 57(1) 25-31. Abstract
Rader,Rb and Belish, TA 1999 Influence of mild to severe flow alterations on invertebrates in three mountain streams. Regulated Rivers: Research & Management. 15(4)353 - 363.
Discussing Hesperoperla pacifica among a few other critters, they comment that "some stoneflies declined or were even locally extirpated" by severe flow alterations due to dams and water abstraction of their habitat.
Richardson,JW; Gaufin,AR 1971 Food habits of some western stonefly nymphs. Transactions of American Entomological Society 97, 91-121.
Discussed as Acroneuria pacifica.
Sandberg,JB 2009 Vibrational communication (drumming) of the western nearctic stonefly genus Hesperoperla (Plecoptera: Perlidae). Illiesia 2009 5(13):146-155. PDF
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 (gills) on page 46.
Stark,BP; Gaufin,AR 1976 The nearctic genera of Perlidae (Plecoptera). Miscellaneous Publications of the Entomological Society of America 10, 1-80. page 30.
Stewart,KW; Stark,BP 2002: Nymphs of North American Stonefly Genera. 2nd edition The Caddis Press, Columbus, Ohio. 510 pages.
Illustrations of nymph on page 344-345, figures 13.21-13.22
Adams,R and Simmons,D 1999 Ecological Effects of Fire Fighting Foams and Retardants. CONFERENCE PROCEEDINGS Australian Bushfire Conference, Albury
http://www.csu.edu.au/special/bushfire99/papers/adams/
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; 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 Hesperoperla pacifica nymph on page 66.
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subgenital plate |
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genital hooks |
head |
terga |
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