Stoneflies - Plecoptera: Perlodidae of Gunnison County, Colorado
Diura knowltoni (Frison 1937)
Updated 14 May 2016
Older publications may refer to this species as Dictyopterygella knowltoni.
On this website:
Key to Perlodidae Nymphs
Baumann,RW, Gaufin,AR and Surdick,RF 1977 The stoneflies (Plecoptera) of the Rocky Mountains. Memoirs of the American Entomological Society 31, 1-208.
Quote from page 125: "The genus Diura is composed of medium-sized, light brown stoneflies with short, conical submental gills. The mesosternal ridge pattern of both adults and nymphs lacks the transverse ridge and arms of the Y-ridge join the posterior corners of the furcal pits. Males are unique within the subfamily because they lack an epiproct (fig. 396). The tenth tergum of the male bears a membranous median triangle on the posterior edge and a few spinules on the dorsal surface. The subgenital plate of the female is briefly produced and truncate or slightly excavated(fig 397.) Only one species of Diura is recorded from the Rocky Mountains. The nymph is brightly colored with brown and yellow transverse stripes on the abdomen."
Quote from page 125: "This species is found in creeks and rivers but is seldom common. The adults emerge from April to June."
Billberg,GJ 1820 Enumeratio insectorum in museo Gust. Joh. Billberg. Typus Gadelianus. 138 pp.
Describes the genus Diura.
Frison,TH 1937 II. Descriptions of Plecoptera with special reference to the Illinois species. Illinois Natural History Survey Bulletin 21 3, 78-99.
Original description as Dictyopterygella knowltoni.
Gaufin,AR; Clubb,R and Newell,R 1974 Studies on the tolerance of aquatic insects to low oxygen concentrations. Great Basin Naturalist 34:45-59. PDF
The authors studied the acute short term tolerance of aquatic insects to low oxygen. They used the 96 hour Median Tolerance Limit. The TLm96 for D. knowltoni was 3.6mg/l and 32% oxygen saturation.
Knight,AW; Gaufin,AR 1966 Altitudinal distribution of stoneflies (Plecoptera) in a Rocky Mountain drainage system. Journal of the Kansas Entomological Society 39 4, 668-675. First page
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 397: "This species is uncommonly collected as adults, but good nymphal populations can be found in small to large-sized streams of the Mountain region, especially in the upper Colorado River basin."
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"
Stewart,KW and Stark,BP 2002 Nymphs of North American Stonefly Genera. 2nd edition The Caddis Press, Columbus, Ohio. 510 pages.
Photo of mature nymph patterns on page 107 figure 6.24. Illustrations of nymph on page 391-392, figures 14.19-14.20
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 Diura knowltoni nymph on page 75, figure 35.
Only visible easily on mature nymphs.
Notice the little knob below the short tooth. Not correct, Diura has no knob (Stewart and Stark, 2002).