Stoneflies - Plecoptera: Nemouridae of Gunnison County, Colorado
Malenka flexura - Twisted Forestfly(Claassen 1923)
Updated 25 Feb 2017
NotesThe genus Malenka was previously named Nemoura. Older publications may refer to this species as Nemoura flexura.
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ReferencesBaumann,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 32: "This species occurs commonly in springs, creeks and small rivers. The adults emerge from March to December. " They show M. flexura is present in Gunnison County.
Claassen,PW 1923 New species of North American Plecoptera. Canadian Entomologist 55, 257-263, 281-292.
Jones,TS and Resh,VH 1988 Movements of adult aquatic insects along a Montana (USA) springbrook. Aquatic insects, 10(2), 99-104. PDF
Abstract: " The occurrence and movement patterns of adult insects along a forested springbrook near Flathead Lake, Montana, USA, were studied during three 15-day periods from 19 June through 9 August 1985, using a two-sided Malaise trap. Of the Plecoptera, numbers of males and gravid females of Malenka flexura gravid females of Zapada frigida and total numbers of Paraperla wilsoni were significantly higher for downstream-flying adults during one to three periods. Of the Trichoptera, numbers of males of Anagepetus debilis were significantly higher for upstream flying adults during one period, and males of Lepidostoma cascadense and gravid females of L. spicata were significantly higher for downstream-flying adults during another period. In none of the 26 species examined in these three orders did females show a statistically significant pattern of upstream flight."
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 392: "The type locality of this species is Boulder County. It has a spotty distribution, which corresponds to it's affinity for habitats influenced by spring-fed water sources. "
Marden,JH and Kramer,MG 1994 Surface-skimming Stoneflies: A possible intermediate stage in insect flight evolution. Science, 266(5184) 427-430. PDF
Discusses Malenka flexura as Nemoura flexura.
Abstract: " Insect wings appear to have evolved from gills used by aquatic forms for ventilation and swimming, yet the nature of intermediate stages remains a mystery. Here a form of nonflying aerodynamic locomotion used by aquatic insects is described, called surface skimming, in which thrust is provided by wing flapping while continuous contact with the water removes the need for total aerodynamic weight support. Stoneflies surface skim with wing areas and muscle power output severely reduced, which indicates that surface skimming could have been an effective form of locomotion for ancestral aquatic insects with small protowings and low muscle power output. "
Stewart,KW and Stark,BP 2002 Nymphs of North American Stonefly Genera. 2nd edition The Caddis Press, Columbus, Ohio. 510 pages.
Illustration of nymph on page 190-191, figure 9.5-9.6
Williams,MC; Lichtwardt,RW 1987 Two new Trichomycete species from Zapada spp. (Stonefly) nymphs with an unusual distribution. Mycologia 79, 473-478.
They found the Trichomycete fungus Genistelloides helicoides in the hindguts of M. flexura.
Brown,WS 2004 Plecoptera or Stoneflies of Gunnison County, Colorado
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