Trichoptera: Rhyacophilidae of Gunnison County, Colorado
Green Rock Worms
Updated 12 Feb 2012
Green when alive although color fades to white in ethanol. Anal proleg lacks apical-lateral spine or spur. Clumps of long branched filamentous gills on the abdomen are easily seen in the field on medium to large larvae.
Common in the East River, Coal Creek and tributaries. The Illinois Natural History Survey (INHS) Database shows this species present at "Parlin at US 50". Allan (1975) reports this species from Cement Creek.
On this website:
Introduction to Rhyacophila
Photos, Map, Museum specimens, DNA - Barcodinglife.org
Allan,JD 1975 The distributional ecology and diversity of benthic insects in Cement Creek, Colorado. Ecology 56:1040-1053. PDF
Banks,N 1911 Descriptions of new species of North American Neuropterid Insects. Transactions of American Entomological Society 37, 335-360.
Banks describes this species for the first time.
Banks, N. 1914. American Trichoptera- notes and descriptions. Canadian Entomologist 46:149-156, 201-204, 252-258, 261-268.
Described as R. acropedes, considered a synonym of R. brunnea by Smith and Manual, 1984 (see below).
Buchwalter,DB; Cain,DJ; Clements,WH; Luoma,SN 2007 Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects. Environmental Science and Technology 41, 4821-4828.
Abstract: "Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunnea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. "
Dobrin, Michelle and Donna J. Giberson 2004 Life history and production of mayflies, stoneflies, and caddisflies (Ephemeroptera, Plecoptera, and Trichoptera) in a spring-fed stream in Prince Edward Island, Canada: evidence for population asynchrony in spring habitats? Can. J. Zool./Rev. Can. Zool. 81(6): 1083-1095. Abstract
Has life history for R. brunnea from Prince Edward Island spring brooks.
Herrmann,SJ; Ruiter,DE and Unzicker,JD 1986 Distribution and records of Colorado Trichoptera. Southwestern Naturalist 31 4, 421-457.
They note the habitat for this species is streams and rivers, the altitudinal range is 2012 to 3261m and adult collection dates are 2 April to 6 September. Quote from page 450: "This rhyacophilid is abundant in Colorado throughout its altitudinal range. Smith and Manual (1984) synonymized R. acropedes Banks 1914 with R. brunnea. All Colorado records before 1984 would be listed as R. acropedes "
Mecom,JO 1972 Productivity and distribution of Trichoptera larvae in a Colorado mountain stream. Hydrobiologia 40(2): 151 - 176. ISSN: 0018-8158 (Paper) 1573-5117 (Online) DOI: 10.1007/BF00016789 Abstract
Discusses this species as R. acropedes. Has life history data from the St Vrain River in Colorado.
Peckarsky,BL 1980 Influence of detritus on colonization of stream invertebrates. Canadian Journal of Fisheries and Aquatic Sciences 37, 957-963.
Discusses this species as R. acropedes.
Peckarsky,Barbara L; Dodson,Stanley I; Conklin,Don J 1985 A key to the aquatic insects of streams in the vicinity of the Rocky Mountain Biological Lab, including chironomid larvae from streams and ponds. Colorado Division of Wildlife, Denver CO. 47 pages.
They include R. acropedes in a larval key. This is probably R. brunnea.
Rader RB and Ward JV. 1988 Influence of regulation on environmental conditions and the macroinvertebrate community in the upper Colorado River. Regulated Rivers: Research and Management 2:597-618.
Discussed as R. acropedes. Quote from page 611: "The reference site was represented by twelve species of caddisflies, including relatively abundant populations of Arctopsyche grandis and Rhyacophila acropedes. Trichopterans at the regulated site, however, were represented by nine rare and three slightly more abundant caddisflies (Hydroptila sp., Brachycentrus americanus, and Hesperophylax designatus). The abundance of net-spinning caddisflies was significantly reduced in the regulated site compared to both reference and recovery locations (p=0.05), as has been reported by several workers (Armitage and Capper, 1976; Müller, 1962; Ward, 1987). "
Smith,SD 1968 The Rhyacophila of the Salmon river drainage of Idaho with special reference to larvae. Annals of the Entomological Society of America 61 3, 655-674.
Has a key to larvae that includes R. acropedes, which we now know as R. brunnea. However the author could not distinguish R. acropedes from the larvae of R. vao. R. vao has been reported from Summit County in Colorado, so it may be present in Gunnison County.
Smith, S. D. 1984 Larvae of Nearctic Rhyacophila, part I: acropedes group. Aquatic Insects 6:37-40.
Smith SD and KL Manuel 1984 Reconsideration of the nearctic species of the Rhyacophila acropedes subgroup based on adults (Trichoptera: Rhyacophilidae). In Proc. Fourth Int. Symp. Trichoptera, JC Morse, ed Dr. W. Junk, The Hague.
Synonymizes R. acropedes as Rhyacophila brunnea.