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Ephemeroptera: Heptageniidae of Gunnison County, Colorado

Epeorus deceptivus
Flat headed mayfly

(McDunnough) 1924
Updated 2 Mar 2022
TSN 100632

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Allan,JD and Feifarek,BP 1988 Prey preference in stoneflies: a comparative analysis of prey vulnerability. Oecologia, 76(4), pp.496-503.

Alvarez,M and Peckarsky,BL 2013 The influence of moss on grazers in high-altitude streams: food, refuge or both? Freshwater Biology, 58(9) 1982-1994. PDF

Edmunds,GF; Allen,RK 1964 The Rocky Mountain species of Epeorus (Iron) Eaton (Ephemeroptera: Heptageniidae). Journal of the Kansas Entomological Society 37 (4) 275-288. Abstract PDF

Lehmkuhl,DM 1968 Observations on the life histories of four species of Epeorus in western Oregon (Ephemeroptera: Heptageniidae). Pan-Pacific Entomologist 44(2):129-137. PDF

McCafferty,WP; Durfee,RS; Kondratieff,BC 1993 Colorado mayflies (Ephemeroptera): an annotated inventory. Southwestern Naturalist 38 3, 252-274. PDF
     Discussed as Iron deceptivus. There are museum specimens mentioned from the Crystal River, East River and Gunnison River. Quote from page 260: "This species is evidently restricted to the intermountain West (Edmunds and Allen, 1964) "

McCafferty,WP and Provonsha, AV The Mayflies of North AmericaSpecies List (Version 8Feb2011)
     Here is the geographic range and synonyms:
Epeorus deceptivus (McDunnough), 1924 [CAN:FN,NW;USA:FN,NW,SW]
    * Cinygma deceptiva McDunnough, 1924 (orig.)
    * Iron deceptivus (McDunnough), 1924 (comb.)

McDunnough,J 1924 New Canadian Ephemeridae with notes, II. Canadian Entomologist 56, 90-98, 113-122, 128-133.

McIntosh,AR; Peckarsky,BL and Taylor,BW 2002 The influence of predatory fish on mayfly drift: extrapolating from experiments to nature. Freshwater Biology 47, 1497-1513. PDF

Peckarsky,BL 1990 Habitat selection by stream-dwelling predatory stoneflies. Canadian Journal of Fisheries and Aquatic Sciences 48, 1069-1076.

Peckarsky,BL 1991a A field test of resource depression by predatory stonefly larvae. Oikos 61 (1) 3-10.

Peckarsky,BL 1991b Is there a coevolutionary arms race between predators and prey? A case study with stoneflies and mayflies. Advances in Ecology 1, 167-180.

Peckarsky,BL 1996 Alternative predator avoidance syndromes of stream-dwelling mayfly larvae. Ecology, 77(6), pp.1888-1905. PDF
     Abstract: "Experiments were conducted to compare the patterns, mechanisms, and costs of predator avoidance behavior among larvae of five species of mayflies that co-occur with the predatory stoneflies, Megarcys signata and Kogotus modestus in western Colorado streams. Mayfly drift dispersal behavior, use of high vs. low food (periphyton or detritus) patches, microhabitat use, positioning, and activity periodicity were observed in the presence and absence of predators in circular flow-through chambers using natural stream water. Also, distances from predators at which prey initiated escape responses were compared among prey and predator species. Costs of predator avoidance behavior were assessed by measuring short-term (24 h) feeding rates of mayflies in the presence or absence of predatory stoneflies whose mouthparts were immobilized (glued) to prevent feeding. The intensity and associated costs of predator avoidance behavior of mayfly species were consistent with their relative rates of predation by stoneflies. Megarcys consumes overwintering generation Baetis bicaudatus > Epeorus longimanus > Cinygmula = Ephemerella; Kogotus consumes summer generation Baetis > Epeorus deceptivus = Cinygmula; Megarcys eats more mayflies than Kogotus. While Megarcys induced drift by Baetis, Epeorus, and Cinygmula, this disruptive predator avoidance behavior only reduced food intake by Baetis and Epeorus. The morphologically defended mayfly species, Ephemerella, neither showed escape behavior from Megarcys, nor any cost of its antipredatory posturing behavior. Only Baetis responded by drifting from Kogotus. No mayfly species shifted microhabitats or spent less time on high-food patches in the presence of foraging stoneflies. However, predators enhanced the nocturnal periodicity of Baetis drift, which was negligible in the absence of stoneflies as long as food was abundant. Lack of food also caused some microhabitat and periodicity shifts and increased the magnitude of both day and night drift of Baetis. Thus, Baetis took more risks of predation by visual, drift-feeding fish not only in the presence of predatory stoneflies, but also when food was low or they were hungry. All other mayflies were generally nocturnal in their use of rock surfaces, as long as food was abundant. Finally, the distances at which different mayfly species initiated acute escape responses were also consistent with relative rates of predation. This study demonstrates alternative predator avoidance syndromes by mayfly species ranging from an initial investment in constitutive morphological defenses (e.g., Ephemerella) to induced, energetically costly predator avoidance behaviors (e.g., Baetis). Although the costs of Ephemerella's constitutive defense are unknown, experiments show that prey dispersal is the mechanism underlying fecundity costs of induced responses by Baetis to predators, rather than microhabitat shifts to less favorable resources or temporal changes in foraging activity. A conceptual model suggests that contrasting resource acquisition modes may account for the evolution and maintenance of alternative predator avoidance syndromes along a continuum from Baetis (high mobility) to heptageniids (intermediate mobility) to Ephemerella (low mobility). Prey dispersal (swimming) to avoid capture results in reduction of otherwise high fecundity by Baetis, which trades off morphological defense for enhanced ability to acquire resources. Thus, improved foraging efficiency is the selection pressure maintaining the highly mobile life style in Baetis, which increases resource acquisition and fecundity, offsetting the high mortality costs associated with this behavior."

Peckarsky,BL; Cowan,CA 1995 Microhabitat and activity periodicity of predatory stoneflies and their mayfly prey in a western Colorado stream. Oikos 74 3, 513-521.

Peckarsky,BL and Penton,MA 1989 Mechanisms of prey selection by stream-dwelling stonefly nymphs. Ecology 70(5) 1203-1218. Abstract

Radford,DS and Hartland-Rowe,R 1971 The life cycles of some stream insects (Ephemeroptera, Plecoptera) in Alberta. The Canadian Entomologist, 103(4) 609-617.
     Names have changed since 1971:
1971 Name 2020 Name
Nemoura besametsa Prostoia besametsa
Epeorus deceptivus Epeorus deceptivus
Epeorus longimanus Epeorus longimanus
Ephemerella coloradensis Drunella coloradensis
Arcynopteryx aurea Perlinodes aurea
Nemoura cinctipes Zapada cinctipes
Nemoura columbiana Zapada columbiana
Nemoura oregonensis Zapada oregonensis
Cinygmula ramaleyi Cinygmula ramaleyi
Ephemerella doddsi Drunella doddsi
Rhithrogena doddsi Rhithrogena hageni
Abstract: " The life histories of Nemoura besametsa, Epeorus deceptivus, Epeorus longimanus, and Ephemerella coloradensis are described as "fast seasonal" types and Arcynopteryx aurea, Nemoura cinctipes, Nemoura columbiana, Nemoura oregonensis, Cinygmula ramaleyi, Ephemerella doddsi, and Rhithrogena doddsi as "slow seasonal" types according to Hynes´ (1961) classification. All of the species are univoltine with the exception of N. cinctipes which may be bivoltine. There seems to be a correlation between life cycles and food availability. A means of ecological separation in the four Nemoura species is elucidated. Stream temperature was found to influence growth rates."

Brown,WS 2004 Mayflies (Ephemeroptera) of Gunnison County, Colorado, USA

"We never tire of each other, the mountain and I." --Lao Tzu