Nova Scotia Spiny Crawler Mayfly

Eurylophella bicoloroides (McDunnough, 1938)

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Insecta (Insects)
State Protection
Not Listed
Not listed or protected by New York State.
Federal Protection
Not Listed
State Conservation Status Rank
Not Ranked - State conservation status not yet assessed.
Global Conservation Status Rank
Vulnerable globally - At moderate risk of extinction due to rarity or other factors; typically 80 or fewer populations or locations in the world, few individuals, restricted range, few remaining acres (or miles of stream), and/or recent and widespread declines.


Did you know?

Mayflies possess several traits thought to be present in some of the earliest insect: They have tails and cannot fold their wings over there body. These traits make mayflies a living example of some of Earth’s more primitive insects (McCafferty 1998).

State Ranking Justification

Additional studies are needed to determine the status of Nova Scotia Spiny Crawler in New York. There are three known locations that were reported prior to 1987.

Conservation and Management


Though there is little documentation of this species, it can be said that there may be many possible threats to Eurylophella bicoloroides and its genus, in general. For example, alterations to this species' habitat could have the potential to cause stress or mortality. Though no research has been done specifically, threats such as the warming of waterways, pollution, and changes in streamflow may all have potential impacts. Structures, such as dams, can alter streamflow and change stream temperature (Zaidel et al. 2021). In addition, deforestation or tree removal along steam banks increases stream temperature (Souza et al. 2020). The use of some agricultural pesticides have been found to increase mortality of some mayfly species (Pristed et l. 2016).

Conservation Strategies and Management Practices

Any measures to reduce water contamination or hydrological alteration such as agricultural run-off, shoreline development, and damming that would affect river flow should be considered when managing for this species (NYS DEC 2005). Consider reducing road salt usage in transportation corridors near streams (NYSDEC 2005). Maintaining a forested buffer around the river would be beneficial to many aquatic macroinvertebrates as it helps reduce siltation and pollution from activities such as farming, logging, and construction. Additionally, where construction is taking place near water systems, measures to reduce siltation as much as possible are recommended. This could include disturbing only the work area to maintain as much vegetation as possible to reduce runoff, working in phases to allow for more centralized control of sedimentation, using sediment traps or ditches to direct runoff away from the river or, stabilizing soil by seeding, mulching, use of blankets, or wool binders. Protect slopes by using silt fences or fiber rolls.

Research Needs

Very little scientific data are available for Eurylophella bicoloroides; its habits, diet, and behavior are relatively unknown. Additionally, it has a very spotty range throughout the Northeast. A better understanding of habitat requirements, especially in aquatic environments, will allow for better management strategies to protect E. bicoloroides.



This species is found within small to medium streams, such as 2nd to 7th order streams (Funk and Sweeny 1994). Generally speaking, species within the genus Eurylophella are usually found in areas of low current velocity, particularly along the margins of streams, where submerged snags and organic debris are present (Funk and Sweeny 1994).

Associated Ecological Communities

  • Confined river (guide)
    The aquatic community of relatively large, fast flowing sections of streams with a moderate to gentle gradient.
  • Rocky headwater stream* (guide)
    The aquatic community of a small- to moderate-sized perennial rocky stream typically with a moderate to steep gradient, and cold water that flows over eroded bedrock, boulders, or cobbles in the area where a stream system originates.
  • Unconfined river* (guide)
    The aquatic community of large, quiet, base level sections of streams with a very low gradient.

* probable association but not confirmed.


New York State Distribution

Nova Scotia Spiny Crawler has been reported from four waterbodies in the following counties in New York: Delaware, Oneida, and Schoharie (Myers et al. 2021, Myers et al. 2010).

Global Distribution

The Nova Scotia Spiny Crawler geographic range has been described occurring from Nova Scotia, Vermont, New York, and Pennsylvania (NatureServe 2022, Myers et al. 2010). According to Funk and Sweeny (1994) this species can have a patchy distribution within is geographic range.

Identification Comments

Identifying Characteristics

Larvae of the Spiny Crawlers family (Ephemerellidae) are known to be 5-15 mm in length at maturity excluding the tail. McCafferty (1998) describes the body as "cylindrical or flattened" and the "long axis of the head tends to be vertically oriented...Blunt to sharp spines are often present dorsally on head, thorax, and/or abdomen". The abdominal segment usually has spines on the sides; gills are not present. Adults Spiny Crawlers have short veins along the margin of the fore wings that are not attached to any other veins (McCafferty 1998).

Characters Most Useful for Identification

Spiny Crawlers larvae lack gills on the abdominal segment. All other mayfly larvae have gills.

Best Life Stage for Proper Identification



Nova Scotia Spiny Crawler Mayfly
Eurylophella bicoloroides (McDunnough, 1938)

  • Kingdom Animalia
    • Phylum Arthropoda (Mandibulates)
      • Class Insecta (Insects)
        • Order Ephemeroptera (Mayflies)
          • Family Ephemerellidae

Additional Resources


Funk, David H., B.W. Sweeny. 1994. The larvae of eastern North American Eurylophella tiensuu (Ephemeroptera: Ephemerellidae). Transitions of the American Entomological Soceiety 120:2009-286.

McCafferty, Patrick W. 1998. Aquatic entomology: the fisherman's and ecologists' illustrated guide to insects and their relatives. Boston, Mass.: Science Books International.

Myers, L. W., B. C. Kondratieff, D. E. Ruiter T. B. Mihuc. 2021 New York and New England Aquatic insect database, Lake Champlain Research Institute, SUNY Plattsburgh, Plattsburgh, NY.

Myers, Luke, Timothy Mihuc, and Boris Kondratieff. 2010. Draft report: Mayflies (Ephemeroptera), Stoneflies (Plecoptera), and Caddisflies (Trichoptera) of the Upper Hudson, Lake Champlain, and Northeastern Lake Ontario watersheds (New York State): A baseline inventory with management considerations for SGCN and other rare and possibly imperiled species.

NatureServe. 2022. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available (Accessed: March 1, 2022).

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

Pristed, Mathias J. S., M. Bundschuh, J.J. Rasmussen. 2016. Multiple exposure routes of a pesticide exacerbate effects on a grazing mayfly. Aquatic Toxicology 178: 190-196.

Souza, Francine N., Rodolfo Mariano, Tassio Moreia, and Sofia Campiolo. 2020. Influence of the landscape in different scales on the EPT community (Ephemeroptera, Plecoptera and Trichoptera) in the Atlantic Forest region. Environmental monitoring and assessment 129: 391-391.

Zaidel, Peter A., A. H. Roy, K. M. Houle, B. Lambert, B. H. Letcher, K. H. Nislow, C. Smith. 2021. Impacts of small dams on stream temperature. Ecological indicators 120:6-11.

About This Guide

This guide was authored by: Every, Zane W.

Information for this guide was last updated on: June 30, 2022

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Eurylophella bicoloroides. Available from: Accessed July 19, 2024.