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Stoneflies - Plecoptera: Taeniopterygidae of Gunnison County, Colorado

Taenionema pallidum
Common Willowfly

(Banks, 1902)
Updated 22 Jan 2019
TSN 102827


Males and Females are macropterous (have long wings). The tiny lobe on tergum ten and narrow epiproct separate this from T. pacificum males. The only sure way to separate Taenionema spp nymphs from Neumoridae is by the short 2nd tarsal segment. Nymphs tend to curl up when preserved in ethanol. A complete diagnosis may be found on page 196 with illustrations on page 226 of Stanger and Baumann (1993).


Small to large streams.

Life History

Stanger and Baumann (1993) report this species has the longest emergence time of any species in the genus. Adults may be collected from Feburary to August. Adults are often found on Salix spp (willow). Kondratieff and Baumann (2002) and Baumann et al (1977) note that this species may be collected as late as August above 3000 meters in Colorado. Most emergence occurs from April to June.

Locations Collected

White Pine Creek and Soap Creek (Stark et al 1973).


Brachyptera (subgenus Taenionema) pallida is a synonym used in Stark et al 1973. Other older publications may refer to this species as Nemoura pallidum. T. nigripennis (Banks) is still split out in Baumann et al 1977. Name endings changed from feminine to neuter (or -a -um and -is to -e) in 1974 after George Steyskal pointed out the details of the Greek root of the word Taenionema (Steyskal, 1976).

Good Links

On this website:
Key to Taenionema Females
Key to Taenionema Males
Taenionema pacificum

Other Websites:
Map - Kondratieff, Boris C. and Richard W. Baumann (coordinators). 2000. Stoneflies of the United States. Jamestown, ND: Northern Prairie Wildlife Research Center Online. (Version 12DEC2003). http://www.npwrc.usgs.gov/resource/distr/insects/sfly/usa/248.htm

Adult Photo - by Riley Nelson from the Web of Life

Nymph Photo by Riley Nelson from the Web of Life


Banks,N 1902 Notes and descriptions of Perlidae. Canadian Entomologist 34:123-125.
     Described as Nemoura pallida.

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 54: "This species is very similar to T. pacifica and some records may have been confused for these two species in the past. The adults emerge from April to June. "
And from page 53, a discussion of T. nigripenne (synonymized by Stanger and Baumann 1993): "This is a very common species in creeks in the Rocky Mountains. Adults exhibit both light and dark color phases. Emergence occurs from March to August."

Carlisle,DM; Clements,WH 2003 Growth and secondary production of aquatic insects along a gradient of Zn contamination in Rocky Mountain streams. Journal North American Benthological Society 22(4), 582-597. Abstract and entire paper
     "Early instars of Taenionema pallidum and Doddsia occidentalis (subfamily Brachypterinae:Taeniopterygidae), were indistinguishable, so these species were lumped because they had similar life histories and growth patterns. -snip-- Production of Taenionema pallidum/Doddsia occidentalis was not statistically different among reference and low Zn streams, but these species were absent from the intermediate and high Zn streams."

Carlisle,DM; Clements,WH 2005 Leaf litter breakdown, microbial respiration and shredder production in metal-polluted streams. Freshwater Biology 50, 380-390. Abstract
     Quote from abstract: "3. Dissolved Zn concentrations varied eightfold among two reference and three polluted streams. Total secondary production of shredders was negatively associated with metal contamination. Secondary production in reference streams was dominated by Taenionema pallidum. Results of previous studies and the current investigation demonstrate that this shredder is highly sensitive to metals in Colorado headwater streams. Leaf litter breakdown rates were similar between reference streams and declined significantly in the polluted streams. Microbial respiration at the most contaminated site was significantly lower than at reference sites.
4. Our results supported the hypothesis that some shredder species contribute disproportionately to leaf litter breakdown. Furthermore, the functionally dominant taxon was also the most sensitive to metal contamination. We conclude that leaf litter breakdown in our study streams lacked functional redundancy and was therefore highly sensitive to contaminant-induced alterations in community structure. We argue for the necessity of simultaneously measuring community structure and ecosystem function in anthropogenically stressed ecosystems."

Duffield,RM and Nelson,CH 1998 Stoneflies (Plecoptera) in the diet of brook trout (Salvelinus fontinalis Mitchell) in Libby Creek, Wyoming, USA. Hydrobiologia 380, 59-65.
     Quote from page 64: "Only a single species of Taeniopterygidae was recovered from the samples. Taeniomena pallidum was represented by adult females and was present from May through July."

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 393: "Stanger and Baumann (1993) considered T. nigripenne (Banks), a species previously reported from Colorado by Stark et al. (1973) and Baumann et al. (1977), as a synonym. Taenionema pallidum is a common species of small to large-sized streams of the Mountain and Plateau regions, and adults can be collected as late as August at elevations above 3,000m."

Short,RA; Canton,SP and Ward,JV 1980 Detrital processing and associated macroinvertebrates in a Colorado mountain stream. Ecology, 61(4), 727-732. PDF
     Taenionema nymphs were found in all 4 of the plant species used to make leaf packs; alder, willow, aspen and pine.

Stanger,JA; Baumann,RW 1993 A revision of the stonefly genus Taenionema (Plecoptera: Taeniopterygidae). Transactions of the American Entomological Society 119 3, 171-229.

Stark,BP; Oblad,BR; Gaufin,AR 1973 An annotated list of the Stoneflies (Plecoptera) of Colorado Part I. Entomological News 84 9, 269-277.
     Discussed as Taenionema nigripenne.

Stewart,KW 2009 New descriptions of North American Taenionema larvae (Plecoptera: Taeniopterygidae). Illiesia 2009 5(12):128-145. PDF

Steyskal, GC 1976 Notes on the nomenclature and taxonomic growth of the Plecoptera. pp 408-410. In: A report on the fifth international symposium on Plecoptera. RW Baumann, ed. Proc. Biol. Soc. Washington. 88:399-428.

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 T. pallidum nymph on page 67, figure 27.


subgenital plate
tergum 10
nymph leg
Brown, Wendy S. 2004 Plecoptera or Stoneflies of Gunnison County, Colorado